Tesi sul tema "Cucumber (Cucumis sativus L.)"

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
Esse trabalho teve como objetivo estimar a capacidade geral e específica de combinação, empregando-se um topcross entre linhagens e populações de pepino japonês. Foram obtidos 16 híbridos experimentais a partir de 2 populações testadoras (geração F2 de Yoshinari e de Natsusuzumi) e 8 linhagens S5 obtidas a partir do híbrido comercial Hokuho, também foi avaliado o híbrido F1 Hokuho, totalizando 27 tratamentos. O delineamento experimental utilizado foi em blocos casualizados com 4 repetições e cada parcela foi constituída de 4 plantas. Foram realizados dois experimentos em duas épocas, onde foram avaliadas as seguintes características relacionadas ao crescimento vegetativo da planta: comprimento das plantas, número de folhas, número de nós, número de brotações laterais e porcentagem de brotações. Também se avaliou o peso de frutos totais, peso de frutos comerciais, número total de frutos, número de frutos comerciais, porcentagem de frutos comerciais e peso médio de frutos comerciais. As análises de capacidades combinatória foram efetuadas de acordo com o modelo de Geraldi & Miranda Filho (1988). A população de Yoshinari (TY) apresentou, em média, melhor capacidade de se combinar com as linhagens de Hokuho. A linhagem L7 apresentou os maiores valores positivos da estimativa da CGC para a maioria das características avaliadas nos dois experimentos e os híbridos H1Y e H1N, que continham a linhagem L1 como parental, foram os que apresentaram maiores valores para a estimativa da CEC com as populações testadoras para a maioria das características avaliadas nos dois experimentos realizados, enquanto os que tinham a linhagem L5 como parental apresentaram os menores valores. Conclui-se, portanto, que há um alto potencial de se extrair linhagens de Yoshinari para cruzamentos com linhagens de Hokuho, a fim de se obter híbridos tão bons quanto o Hokuho.
The objective of the present work was obtain general and specific combining ability estimates, using a top cross between lines and japanese cucumber populations. It was obtained 16 experimental hybrids starting from 2 test populations (Yoshinari and Natsusuzumi) and 8 S5 lines obtained starting from the Hokuho commercial hybrid. The Hokuho hybrid F1 was also evaluated, totaling 27 treatments. The experimental design used was randomized block with four replications and for plant per plot. Were evaluated the following characteristics related to the vegetative growth of the plant: length of the plants, number of leaves, number of us, number of lateral produce and produce percentage. Related to the production it was evaluated: weight of total fruits, weight of commercial fruits, total number of fruits, number of commercial fruits, percentage of commercial fruits and weigh medium of commercial fruits. The analyses of combining ability were evaluated in agreement with the model of Geraldi & Miranda Filho (1988). The Yoshinari of population (TY) presented, on average, better combining ability with the lines of Hokuho, the lines L7 presented the largest positive values of gi for most of the evaluated characteristics in the two experiments and hybrids with the lines L1 it was the one that it presented larger values for CEC with the test populations for most of the evaluated characteristics in the two accomplished experiments, while the hybrids of lines L5 showed the smallest values. It is ended that there is a high potential of extracting lines of Yoshinari for crossings with lines of Hokuho, in order to obtain hybrid as good as Hokuho, with the advantage of being adapted to national conditions.

Orientador: Antonio Ismael Inácio Cardoso
Banca: Norberto da Silva
Banca: Maurício Dutra Zanotto
Banca: Paulo Cesar Tavares de Melo
Banca: Wilson Roberto Maluf
Resumo: Esse trabalho teve como objetivo estimar a capacidade geral e específica de combinação, empregando-se um "topcross" entre linhagens e populações de pepino japonês. Foram obtidos 16 híbridos experimentais a partir de 2 populações testadoras (geração F2 de Yoshinari e de Natsusuzumi) e 8 linhagens S5 obtidas a partir do híbrido comercial Hokuho, também foi avaliado o híbrido F1 Hokuho, totalizando 27 tratamentos. O delineamento experimental utilizado foi em blocos casualizados com 4 repetições e cada parcela foi constituída de 4 plantas. Foram realizados dois experimentos em duas épocas, onde foram avaliadas as seguintes características relacionadas ao crescimento vegetativo da planta: comprimento das plantas, número de folhas, número de nós, número de brotações laterais e porcentagem de brotações. Também se avaliou o peso de frutos totais, peso de frutos comerciais, número total de frutos, número de frutos comerciais, porcentagem de frutos comerciais e peso médio de frutos comerciais. As análises de capacidades combinatória foram efetuadas de acordo com o modelo de Geraldi & Miranda Filho (1988). A população de Yoshinari (TY) apresentou, em média, melhor capacidade de se combinar com as linhagens de Hokuho. A linhagem L7 apresentou os maiores valores positivos da estimativa da CGC para a maioria das características avaliadas nos dois experimentos e os híbridos H1Y e H1N, que continham a linhagem L1 como parental, foram os que apresentaram maiores valores para a estimativa da CEC com as populações testadoras para a maioria das características avaliadas nos dois experimentos realizados, enquanto os que tinham a linhagem L5 como parental apresentaram os menores valores. Conclui-se, portanto, que há um alto potencial de se extrair linhagens de Yoshinari para cruzamentos com linhagens de Hokuho, a fim de se obter híbridos tão bons quanto o Hokuho.
Abstract: The objective of the present work was obtain general and specific combining ability estimates, using a top cross between lines and japanese cucumber populations. It was obtained 16 experimental hybrids starting from 2 test populations (Yoshinari and Natsusuzumi) and 8 S5 lines obtained starting from the Hokuho commercial hybrid. The Hokuho hybrid F1 was also evaluated, totaling 27 treatments. The experimental design used was randomized block with four replications and for plant per plot. Were evaluated the following characteristics related to the vegetative growth of the plant: length of the plants, number of leaves, number of us, number of lateral produce and produce percentage. Related to the production it was evaluated: weight of total fruits, weight of commercial fruits, total number of fruits, number of commercial fruits, percentage of commercial fruits and weigh medium of commercial fruits. The analyses of combining ability were evaluated in agreement with the model of Geraldi & Miranda Filho (1988). The Yoshinari of population (TY) presented, on average, better combining ability with the lines of Hokuho, the lines L7 presented the largest positive values of gi for most of the evaluated characteristics in the two experiments and hybrids with the lines L1 it was the one that it presented larger values for CEC with the test populations for most of the evaluated characteristics in the two accomplished experiments, while the hybrids of lines L5 showed the smallest values. It is ended that there is a high potential of extracting lines of Yoshinari for crossings with lines of Hokuho, in order to obtain hybrid as good as Hokuho, with the advantage of being adapted to national conditions.
Doutor

Light and phytohormones, such as cytokinins, have been known to play a pivotal role in numerous physiological processes in plant cells. Previous work in our laboratory has revealed the light- and cytokinin- modulated changes both in the levels of specific tRNA species and their modified nucleotide contents, in addition to the characterization of specific tRNAs and tRNA genes from higher plants. The plant hormone cytokinin, which is of particular interest to us has been implicated to be involved in processes such as induction of cell division, plastid biogenesis and delay of senescence. Ongoing work in our laboratory also points towards the role of Ca2+ as a second messenger in cytokinin mediated gene expression. With the objective of isolation of specific tRNA genes which could then be used as probes to study the light- and phytohormone- induced changes in the levels of respective functional mature tRNAs, a previously isolated clone containing a 6.6kb insert that hybridized with 3 end labeled cucumber total cellular tRNA was sequenced by the dideoxy chain termination method. Sequence analysis of the 6.6 kb DNA fragment has revealed a chloroplast genome DNA fragment containing the trnNGUU and trnRACG genes in addition to the genes coding for the ribosomal RNAs 4.5S, 5S and 23S as well as the protein coding genes ccsA (cytochrome c-synthesis) and ndhD(NADH plastoquinone oxidoreductase).These genes were found to be arranged in the order-23S-4.5S-5S-trnRACG-trnNGUU-ccsA-ndhD. This shows a divergence from the gene organization in the completely sequenced chloroplast genomes of other higher plant species such as tobacco, maize, rice and Arabidopsis, especially with regard to the absence of a highly conserved trnLUAG gene that has been shown to be present in the trnNGUU-ndhD intergenic region. The cucumber chloroplast trnNGUU and trnRACG genes have shown very high homology (>90%) whereas ccsA and ndhD show 50-61% similarity to corresponding genes from chloroplast genomes of other plant species. The relative levels of tRNAArg and tRNAAsn were determined by Northern analysis using the tRNA gene probes, in etiolated excised cucumber cotyledons treated with light or phytohormones, such as cytokinin (BA) and auxin (2,4-D). Light and phytohormones were found to significantly increase the levels of tRNAArg unlike in the case tRNAAsn where no significant changes in the levels were observed. This result points towards the regulation of relative levels of specific tRNA species by light and cytokinin so as to match the codon usage of the mRNA population during light- and cytokinin- induced plant development in cucumber. Northern analyses were also performed to monitor the relative transcript levels of the plastid encoded ccsA and ndhD in etiolated excised cucumber cotyledons treated with light or phytohormones. ccsA transcript levels were found to be significantly reduced in auxin treated cucumber cotyledons where as exogenous application of cytokinin to either dark-grown or light exposed cotyledons did not seem to have any pronounced effect. ndhD transcripts were found to be up-regulated by cytokinin treatment or light exposure in comparison to un-treated controls probably indicating a point of overlap in the light/ cytokinin mediated signal transduction pathways. Auxin treatment on the other hand was found to down-regulate ndhD transcript levels also. Recent studies from our laboratory have demonstrated the involvement of a calcium-dependent protein kinase(CDPK) in the cytokinin-signal transduction pathway associated with the induction of pathogenesis-related proteins (chitinase and β 1-3 modulation of nuclear-encoded CDPK transcripts in response to light and exogenously added phytohormones such as cytokinins and auxin. Towards this end, partial CDPK cDNAs were generated from Cucumis Sativus by RT-PCR using degenerate primers designed based on the conserved regions of the known CDPK proteins available in the database, cloned in pGEM-T and sequenced. Sequence analysis of twenty partial cDNA clones revealed the presence of at least four CDPK isoforms in Cucumis sativus (CuCDPK 1-4). Of the four partial CDPK cDNAs, the tissue-specific expression level of CuCDPK3 was studied using the highly sensitive Taqman Analysis (Quantitative RT-PCR). The results obtained indicate that, in excised dark-grown cucumber cotyledons light and cytokinin were found to up-regulate the levels of CuCDPK3 unlike auxin, which was found to have no significant effect. In cucumber hypocotyls, which had the highest levels of CuCDPK3, light was found to have a down-regulatory effect whereas cytokinin and auxin did not bring about any significant changes in the levels of CuCDPK3. In cucumber root tissue, both light and cytokinin were found to have a down-regulatory effect on the levels of CuCDPK3, unlike auxin. The southern analysis of cucumber genomic DNA revealed a CDPK multi-gene family in cucumber. Since cytokinins have been known to play a role in both etioplast and chloroplast biogenesis and since various groups have recently reported the presence of higher plant homologues of bacterial cell-division protein FtsZ and the requirement of plant nuclear-encoded FtsZs for plastid division, efforts were also made to isolate and to study the expression of cucumber FtsZ in dark-grown cucumber cotyledon tissue treated exogenously with light/phytohormones. Towards this end, a partial FtsZ cDNA was generated from cucumber by RT-PCR using degenerate primers designed based on conserved regions of known plant FtsZ proteins. Results of the Taqman Analysis indicate that cytokinin, unlike auxin, mimics the action of light by increasing the levels of CuFtsZ transcripts in dark-grown cotyledon tissue suggesting the involvement of FtsZ in cytokinin-induced plastid-biogenesis.

This thesis is concerned with the following areas: first, the nature of the developmental modulations in mitochondrial function, and the role of coarse control, at the level of protein synthesis, in bringing them about; and secondly, the importance of mitochondrial reactions in the regulation of cellular metabolism. Changes in respiratory physiology in developing cotyledons have been characterised and correlated with changing metabolic phases. During lipid mobilisation, carbon is diverted away from the decarboxylating reactions of the TCA cycle, whereas the capacity exists for full cycle operation in the photosynthetic phase. Mitochondrial glycine oxidation, necessary for the maintenance of the photorespiratory cycle, is induced during photosynthetic development. The non-phosphorylating pathway of electron transport, via the alternative oxidase, is present, and the access of substrates to this pathway appears to be regulated such that high rates of succinate and glycine oxidation can occur simultaneously. These changes are brought about, at least in part, by protein synthesis. The steps regulating succinate oxidation by isolated cotyledon mitochondria have been determined using the quantitative techniques of metabolic control theory. During lipid mobilisation, succinate metabolism is regulated by the adenine nucleotide translocator and the processes of succinate uptake into the mitochondria. A mitochondrial r^ole in the integration of biosynthesis and degradation is proposed in the light of these results. In the photosynthetic phase, the regulation of succinate oxidation is by the steps of the respiratory chain. There is evidence to suggest that variation in succinate oxidation rates during development is a result of the synthesis of specific proteins. Studies into the pathway of pyruvate metabolism in developing cotyledons indicate that carbon may be diverted into the TCA cycle during chloroplast biogenesis, through pyruvate production by the mitochondrially located NAD-malic enzyme. It is suggested that this mitochondrial route of carbon entry would enable TCA cycle flux to be regulated by the demand for intermediates required for biosynthetic pathways, rather than the rate of sucrose production from lipid. Evidence is presented for the more conventional route of carbon entry into the TCA cycle from cytosolic pyruvate during the photosynthetic phase. Results indicate that the developmental modulation of pyruvate metabolism is regulated at the level of protein synthesis. Application of metabolic control theory to in vitro systems capable of hexose production from organic acids, provides further support for the proposed r^ole of mitochondria during lipid mobilisation. The adenine nucleotide translocator and other mitochondrial steps have significant flux control coefficients for hexose production in vitro. The results presented are used as the basis for the development of a hypothesis concerning the importance of mitochondria in the regulation of plant metabolism.

On the protected horticultural industry, the artificial lighting is a common practice under reduced natural light radiation or self-shading of the leaves at lower canopies. Those conditions affect the photosynthetic activity and the yield is limited. In the last decade, the use of lamps with LED technology for supplemental lighting has increased on high-latitude countries. LED lights are more energy efficient and have lower power consumption. On these lamps is possible to regulate the intensity (quantity) and the radiation (quality) on the ideal range of light spectrum in order to convert the luminous energy into chemical energy. Not reports of use of this technology were found at the tropics. Thus, the objective of this work was to evaluate physiological parameters related with the photosynthetic activity and the yield on mini-cucumber plants grown on protected environment with supplemental LED interlighting. At Piracicaba (Sao Paulo), Brazil, three experiments were conducted on LED interlighting equipped greenhouse, two at winter seasons (2015 and 2016 years) and one at summer season (2017 year) using mini-cucumber hybrid Larino. Through the three stands, was verified an increase on the photosynthesis in the leaves and the commercial productivity of the mini-cucumber due to the LED lighting use. This increase on the commercial yield ranged between 13 and 30%, being higher the effect on the summer season. At the first stand, in addition to the light effect, grafted plants were tested. On this case, the photosynthetic rate increased with grafted plants when treated with LEDs. However, the yield did not increase with grafting. Postharvest parameters as titratable acidity, total soluble solids and long shelf life did not increase as consequence of supplemental LED lighting. Studying the light response curves, it was verified that above a photosynthetic photon flux density of 400 μmol m-2s-1, plants treated with supplemental lighting showed higher values of net CO2 assimilation. The light compensation point was also higher on plants with LEDs. In the case of the CO2 response curve, plants treated with LED lighting verified higher increase on the CO2 assimilation rate when the plant internal CO2 concentration increased. Parameters like Rubisco carboxylase activity, rate of electron transport and leaf dark respiration were also higher on plants under supplemental LED lighting. The lower consumption of electricity and the yield increase on the summer stand allowed registering greater energy and light efficiency on this cycle when compared with the winter stands. For the same reason, the cost analysis revealed that only at the summer stand the LED interlighting was profitable. At that time, the total net income was positive and the benefit cost ratio favorable (1.15).
Na produção hortícola em ambiente protegido, o emprego de luz artificial é uma prática comum, quando condições de radiação natural reduzidas ou o autosombreamento das folhas nos estratos médio e inferior do dossel prejudicam a atividade fotossintética da planta, e consequentemente, limitam a produtividade. Na última década, em países de alta latitude, tem aumentado o uso de lâmpadas com tecnologia de luz LED para fazer essa suplementação luminosa. As luzes do tipo LED são mais eficientes energeticamente e apresentam baixo consumo de energia. Também nessas lâmpadas é possível regular a intensidade (quantidade) e a radiação (qualidade) na faixa ideal do espectro de luz visível para a conversão da energia luminosa em energia química. Em países de clima tropical, experiências dessa natureza não estão reportadas. Assim, foi realizado este trabalho com o objetivo de avaliar parâmetros fisiológicos relacionados com a atividade fotossintética e a produtividade de minipepino cultivado em um ambiente protegido com suplementação luminosa de tipo LED. Em Piracicaba (SP), foram conduzidos três experimentos em casa de vegetação, sendo realizados no inverno (anos 2015 e 2016) e no verão (ano 2017), usando plantas de minipepino híbrido Larino. Foi constatado nos três ciclos aumento na fotossíntese da planta e na produção de pepino comercial devido ao emprego da luz LED. Esse aumento no rendimento comercial variou entre 13 e 30%, sendo maior o efeito no ciclo do verão. No primeiro ciclo além do efeito da luz LED, plantas enxertadas foram testadas. Nesse caso, as plantas enxertadas mostraram também aumento na taxa fotossintética quando submetidas à suplementação luminosa, porém a produtividade não aumentou com a enxertia. Parâmetros de pós-colheita como acidez titulável, teor de sólidos solúveis e vida de prateleira não aumentaram pela suplementação com LED. Estudando as curvas de resposta à luz foi constatado que acima de 400 μmol m-2s-1 na densidade do fluxo de fótons, as plantas com suplementação luminosa mostraram valores maiores na taxa de assimilação líquida de CO2. O ponto de compensação à luz também foi superior em plantas com LED. No caso da curva de resposta ao CO2, as plantas tratadas com luz LED mostraram maior incremento na taxa de assimilação de CO2 quando a concentração interna de CO2 na planta aumentou. Parâmetros como atividade da Rubisco carboxilase, taxa de transporte de elétrons e a respiração obscura foram também maiores em plantas sob luz LED. O menor consumo de eletricidade junto com o aumento na produtividade no ciclo de verão favoreceu maior eficiência no uso da energia e da luz nesse ciclo, quando comparado com os ciclos de inverno. Por esse mesmo motivo, a análise de custos revelou que a suplementação luminosa com luz LED somente foi benéfica no ciclo de verão. Nessa época, a renda líquida total foi positiva e a relação custo beneficio favorável (1.15).

Cucumber root rot caused by Pythium aphanidermatum can be suppressed by introduced plant growth-promoting rhizobacteria (PGPR). Preliminary experiments clarified that this root disease could be suppressed by strains of Pseudomonas aureofaciens, P. corrugata, and P. fluorescens. To determine whether the mechanism was a systemic resistance induced by PGPR, a split root technique was employed on greenhouse cucumbers grown in soilless substrates. On the split roots, bacteria which were introduced into one side of the root were completely separated from pathogen challenged-inoculated roots-on the other side of the roots. Results from the series of experiments conducted with this design demonstrated that (i) the resistance against root rot induced by PGPR was systemic, (ii) germination of P. aphanidermatum zoospores was reduced in extracts from bacterized roots compared to non-treated control, and (iii) spread of Pythium mycelia was delayed and zoospore germination was inhibited on the distant induced root, compared to the non-bacterized control. Furthermore, enzyme analysis indicated that phenylalanine ammonia lyase, peroxidase and polyphenoloxidase increased on cucumber roots two days after they were bacterized with Pseudomonas strains 13 or 63--28. When the bacterized roots were challenged with P. aphanidermatum, these plant defense enzymes increased as the symptoms appeared, but this accumulation of enzymes was not any higher on roots induced with each of the Pseudomonas strains compared to the Pythium inoculated control. This enzyme stimulation was also systemically induced by PGPR or P. aphanidermatum on cucumber roots. The patterns of iso-peroxidase induced with the PGPR and P. aphanidermatum treatments were different. High levels of salicylic acid (SA) accumulated in bacteria-induced roots, as well as in pathogen-infected roots, which suggests that SA may be associated with cucumber resistance response. But exogenous application of SA did not induce any systemi

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Foram conduzidos dois experimentos na FCA/UNESP, objetivando avaliar a depressão causada por endogamia com sucessivas gerações de autofecundação em uma população de pepino do tipo japonês. No primeiro experimento foram avaliadas características de produção de frutos imaturos no período de 21/08/2002 à 29/11/2002 em ambiente protegido. No segundo experimento foram avaliadas características de produção e qualidade de sementes no período de 12/03/2003 à 13/06/2003 em condições de campo. A partir do intercruzamento entre plantas do híbrido Natsu suzumi foi obtida a geração F2, considerada como população S0. Obtiveram-se progênies S1, S2, S3, S4 e S5, através de autofecundações sucessivas pelo método do SSD ('Single Seed Descent'). Ao partir da mistura ao acaso de sementes de progênies com igual número de autofecundações sucessivas foram obtidas cinco populações denominadas de população S1 a população S5. Foram sete tratamentos (híbrido Natsu suzumi, populações S0 a S5) e o delineamento experimental foi em blocos ao acaso, com seis e quatro repetições no primeiro e segundo experimento, respectivamente e cinco plantas por parcela nos dois experimentos. No primeiro experimento (frutos imaturos) foram avaliados, número de folhas, comprimento da haste principal, número e massa de frutos, total e comercial, número de nós e porcentagem de brotações. No segundo experimento (frutos maduros) avaliaram-se características relacionadas com produção (número e massa de sementes por planta e por fruto) e qualidade de sementes (teste padrão de germinação, primeira contagem de sementes, índice de velocidade de germinação, massa de 100 sementes). Foram realizadas as análises de variância para cada característica, e as médias dos tratamentos foram comparadas pelo teste de Tukey (%). Também foram realizados análises de variância apenas com as seis...
Two experiments were set up at FCA/UNESP. The objective of this work was to evaluate the inbreeding depression with successive generations of self pollination in a cucumber Japanese population. It was studied one population F2 obtained from a commercial hybrid (Natsu suzumi) considered as S0 population. In the first experiment were appraised characteristics of production of immature fruits in the period of 21/08/2002 to 29/11/2002 in protected cultivation. In the second experiment were appraised seed production and quality in the period of 12/03/2003 to 13/06/2003 in open field conditions. It was obtained progenies S1, S2, S3, S4 and S5 through the 'Single Seed Descent' methodology. It was used randomized blocks with seven treatments (different generations of self pollination - S0 to S5 and the hybrid Natsu suzumi) six and four replicates in the first and second experiment and five plants per plot in both. In the first experiment (immature fruits) were evaluated number of leaves, length of the main stem, number and weight of fruits, total and commercial, number of nodes and vines percentage. In the second experiment (mature fruit) characteristic related with production were evaluated (number and weight of seeds per plant and per fruit) and quality of seeds (germination test, first counted of seeds, index of germination speed and weight of 100 seeds). The variance analyses were accomplished each characteristic and the averages of the treatments were compared by the test of Tukey (%). Also accomplished just with the six inbreed generations to evaluate the possible inbreeding depression (without including the commercial hybrid). In the comparison among the population differences were not observed for the characteristics appraised showing there were not production loss for inbreeding in this population. However, for the characteristics length of the main stem, number of total fruit, weight of seeds per fruit and seed number per fruit the commercial.

Orientador: Antonio Ismael Inácio Cardoso
Banca: Noberto da Silva
Banca: Keigo Minami
Resumo: Foram conduzidos dois experimentos na FCA/UNESP, objetivando avaliar a depressão causada por endogamia com sucessivas gerações de autofecundação em uma população de pepino do tipo japonês. No primeiro experimento foram avaliadas características de produção de frutos imaturos no período de 21/08/2002 à 29/11/2002 em ambiente protegido. No segundo experimento foram avaliadas características de produção e qualidade de sementes no período de 12/03/2003 à 13/06/2003 em condições de campo. A partir do intercruzamento entre plantas do híbrido Natsu suzumi foi obtida a geração F2, considerada como população S0. Obtiveram-se progênies S1, S2, S3, S4 e S5, através de autofecundações sucessivas pelo método do SSD ('Single Seed Descent'). Ao partir da mistura ao acaso de sementes de progênies com igual número de autofecundações sucessivas foram obtidas cinco populações denominadas de população S1 a população S5. Foram sete tratamentos (híbrido Natsu suzumi, populações S0 a S5) e o delineamento experimental foi em blocos ao acaso, com seis e quatro repetições no primeiro e segundo experimento, respectivamente e cinco plantas por parcela nos dois experimentos. No primeiro experimento (frutos imaturos) foram avaliados, número de folhas, comprimento da haste principal, número e massa de frutos, total e comercial, número de nós e porcentagem de brotações. No segundo experimento (frutos maduros) avaliaram-se características relacionadas com produção (número e massa de sementes por planta e por fruto) e qualidade de sementes (teste padrão de germinação, primeira contagem de sementes, índice de velocidade de germinação, massa de 100 sementes). Foram realizadas as análises de variância para cada característica, e as médias dos tratamentos foram comparadas pelo teste de Tukey (%). Também foram realizados análises de variância apenas com as seis... (Resumo completo, clicar acesso eletrônico abaixo)
Abstract: Two experiments were set up at FCA/UNESP. The objective of this work was to evaluate the inbreeding depression with successive generations of self pollination in a cucumber Japanese population. It was studied one population F2 obtained from a commercial hybrid (Natsu suzumi) considered as S0 population. In the first experiment were appraised characteristics of production of immature fruits in the period of 21/08/2002 to 29/11/2002 in protected cultivation. In the second experiment were appraised seed production and quality in the period of 12/03/2003 to 13/06/2003 in open field conditions. It was obtained progenies S1, S2, S3, S4 and S5 through the 'Single Seed Descent' methodology. It was used randomized blocks with seven treatments (different generations of self pollination - S0 to S5 and the hybrid Natsu suzumi) six and four replicates in the first and second experiment and five plants per plot in both. In the first experiment (immature fruits) were evaluated number of leaves, length of the main stem, number and weight of fruits, total and commercial, number of nodes and vines percentage. In the second experiment (mature fruit) characteristic related with production were evaluated (number and weight of seeds per plant and per fruit) and quality of seeds (germination test, first counted of seeds, index of germination speed and weight of 100 seeds). The variance analyses were accomplished each characteristic and the averages of the treatments were compared by the test of Tukey (%). Also accomplished just with the six inbreed generations to evaluate the possible inbreeding depression (without including the commercial hybrid). In the comparison among the population differences were not observed for the characteristics appraised showing there were not production loss for inbreeding in this population. However, for the characteristics length of the main stem, number of total fruit, weight of seeds per fruit and seed number per fruit the commercial.
Mestre

Thesis (PhD(Agric) (Agronomy))--University of Stellenbosch, 2009.
ENGLISH ABSTRACT: The use of capacitance water sensors for the scheduling of irrigation for hydroponic tomato and cucumber crops grown in coir was investigated in a series of laboratory and glasshouse experiments in the Free State province of South Africa. Laboratory experiments in a climate controlled chamber were conducted to accurately calibrate ECH2O capacitance sensors, models EC-10 and EC-20, in coir with an improved calibration procedure. Water content predictions by the coir-specific calibration and manufacturer’s calibration equations were compared to actual water content measured from mass loss of the coir sample. The manufacturer’s calibration equation indicated a poor accuracy of prediction, which mostly underestimated the volumetric water content, compared to the near perfect prediction of the coir-specific calibration of individual sensors. A rapid calibration procedure for EC-10 and EC-20 sensors was proposed to reduce the calibration time of the sensors and promote their commercial use for irrigation management in coir. The accuracy of prediction by the rapid calibration procedure for the plant available water content range was high for both EC-10 and EC-20 sensors and allowed for the compensation for variation between sensors. Glasshouse studies aimed to characterise the water retention and ability of coir to supply water to greenhouse tomato and cucumber crops through the continuous monitoring of medium water content in small and large growing bags with the EC-10 and EC-20 capacitance sensors during a drying cycle, compared to well-watered plants. Stages of crop water stress were identified and, based only on the plant’s response to the drying cycle, it was suggested that water depletion can be allowed to the point of mild water stress for both greenhouse tomato and cucumber crops, which can be detected by soil water sensors. In a second series of glasshouse experiments, the identified stages of crop water stress were used to determine and apply depletion levels in coir and compare this irrigation strategy to a well-watered treatment for greenhouse cucumber and tomato plants, with regard to the water balance components, yield and water use efficiency for different bag sizes. Results indicated that irrigation was successfully managed to the pre-determined water depletion levels for cucumber and tomato plants in coir, through the use of in situ calibrated capacitance sensors. For both crops the depletion of water varied between bag sizes, indicating that various bag sizes require different irrigation management strategies. Scheduling to the highest pre-determined by 124 L m-2 in the small and 240 L m-2 in the large bags for cucumbers and 427 L m-2 in the small and 487 L m-2 in the large bags for tomato plants, compared to the well-watered treatments. Yields achieved by the greenhouse tomato plants in the large growing bags and cucumber plants in the small and large bags were maintained or improved when scheduled to the highest depletion level (approximately 60% available water content) compared to the well-watered treatment. The combination of reduced irrigation and improved or maintained yields resulted in improved water use efficiencies (based on irrigation and transpiration) for the highest depletion level compared to the well-watered treatments. In all glasshouse experiments the well-watered treatment resulted in luxury water use by the plants. Finally, a study was conducted in order to compare crop water stress of greenhouse cucumber and tomato plants under luxury water supply and cyclic water deficit conditions. The comparison was based on the transpiration ratio and yield, while the use of capacitance sensors was evaluated for irrigation scheduling in coir for both crops. Transpiration data indicated that cucumber and tomato plants subjected to luxury water supply experience water stress earlier than plants subjected to cyclic water deficit conditions, irrespective of bag size. Results also indicated that irrigation scheduling according to water depletion levels in small bags is not yet recommended for greenhouse tomato and cucumber plants grown in coir, until further research is conducted. Scheduling to water depletion levels in large bags is, however, justified by the improved or maintained yields of the greenhouse cucumber and tomato plants. The estimated depletion levels for large bags beyond which yield are reduced was at 85% for tomatoes and 70% for cucumbers. In conclusion, the results clearly indicated that the use of capacitance sensors in large growing bags improves irrigation management of hydroponic cucumbers and tomatoes in coir by eliminating over-irrigation and improving water use efficiency. More research is needed before a conclusion can be made regarding irrigation scheduling with capacitance sensors in small growing bags.
AFRIKAANSE OPSOMMING: Die gebruik van kapasitansie water sensors vir besproeiingskedulering van tamatie en komkommer plante wat hidroponies in kokosveen gegroei is, is ondersoek in ‘n reeks laboratorium en glashuis eksperimente in die Vrystaat provinsie van Suid Afrika. Laboratorium eksperimente is uitgevoer in ‘n klimaat beheerde kas om ECH2O kapasitansie sensors, modelle EC-10 en EC-20, akkuraat te kalibreer vir kokosveen deur ’n verbeterde kalibrasie prosedure. Waterinhoud voorspellings deur die kokosveen spesifieke kalibrasie en die vervaardiger se kalibrasie vergelykings is vergelyk met die werklike waterinhoud wat gemeet is deur die kokosveen monster se massaverlies te monitor. Akkuraatheid van voorspelling deur die vervaardiger se kalibrasie vergelykings was swak en het meestal die volumetriese waterinhoud onderskat in vergelyking met die byna perfekte voorspelling deur die kokosveen spesifieke kalibrasie van individuele sensors. ’n Vinnige kalibrasie prosedure vir die EC-10 en EC-20 sensors is voorgestel om die kalibrasie tyd te verkort en die kommersiële gebruik van die sensors vir besproeiingsbestuur in kokosveen aan te moedig. Die akkuraatheid van voorspelling deur die vinnige kalibrasie prosedure, binne die grense van plant beskikbare waterinhoud, was hoog vir beide EC-10 en EC-20 sensors, terwyl die prosedure ook voorsiening maak vir variasie tussen sensors. Glashuis studies is uitgevoer om die water retensie en vermoë van kokosveen om water te voorsien aan tamatie en komkommer gewasse in kweekhuise, te karakteriseer. Dit is bereik deur die mediumwaterinhoud van klein en groot plantsakke deurlopend te monitor met behulp van die EC-10 en EC-20 kapasitansie sensors gedurende ’n uitdroging siklus, en dit te vergelyk met ’n waterryke behandeling vir elke gewas waarvolgens die plante agt keer per dag besproei is. Fases van gewas waterstremming is geïdentifiseer en, volgens die reaksie van die plant tot die drogingsiklus, is dit voorgestel dat wateronttrekking toegelaat kan word tot die punt van matige waterstremming wat aangewys kan word deur kapasitansie water sensors vir beide kweekhuis tamatie en komkommer gewasse. In ’n tweede reeks glashuis eksperimente is die geïdentifiseerde fases van gewas waterstremming gebruik om onttrekkingsvlakke vir kokosveen te bepaal en toe te pas as besproeiingskeduleringstrategie vir kweekhuis komkommer en tamatie plante. Toegepaste vlakke is vir elke gewas vergelyk met ’n waterryke behandeling ten opsigte van die waterbalans komponente, opbrengs en watergebruiksdoeltreffendheid in verskillede sakgroottes. Resultate het aangedui dat besproeiing suksesvol bestuur is tot die voorafbepaalde wateronttrekkingsvlakke vir komkommer entamatie plante in kokosveen, deur gebruik te maak van in situ gekalibreerde kapasitansie sensors. Die onttrekking van water deur beide gewasse het verskil tussen klein en groot sakke, wat aangedui het dat verskillende sakgroottes verskillende besproeiingsbestuur strategieë vereis. Skedulering tot die hoogste voorafbepaalde onttrekkingsvlak het, in vergelyking met die waterryke behandelings, besproeiing verminder met 124 L m-2 in die klein en 240 L m-2 in die groot sakke vir komkommers, en 427 L m-2 in die klein en 487 L m-2 in die groot sakke vir tamatie plante. Opbrengste van kweekhuis tamatie plante in die groot plantsakke en komkommer plante in die klein en groot sakke is gehandhaaf of verbeter deur skedulering tot die hoogste onttrekkingsvlak (ongeveer 60% van beskikbare water inhoud), in vergelyking met die waterryke behandeling. Die kombinasie van verminderde besproeiing en verbeterde of gehandhaafde opbrengste het gelei tot verbeterde watergebruiksdoeltreffendheid (besproeiing en transpirasie) vir die hoogste onttrekkingsvlak, in vergelyking met die waterryke behandelings. In al die glashuis eksperimente het die waterryke behandeling gelei tot oorvloedige watergebruik deur plante. ’n Finale studie is uitgevoer om gewas waterstremming van kweekhuis komkommer en tamatie plante wat onderwerp is aan oorvloedige watervoorsiening deur agt keer per dag te besproei en sikliese watertekorttoestande, te vergelyk. Die vergelyking is gebaseer op die transpirasie verhouding en opbrengs, terwyl die gebruik van kapasitansie sensors vir besproeiingskedulering in kokosveen vir beide gewasse geëvalueer is. Transpirasie data het aangedui dat komkommer en tamatie plante wat onderwerp is aan oorvloedige watervoorsiening vroeër waterstremming ervaar as plante wat onderwerp is aan sikliese watertekorttoestande, ongeag van die sakgrootte. Resultate het aangedui dat besproeiingskedulering volgens wateronttrekkingsvlakke vir klein sakke nog nie aanbeveel kan word vir kweekhuis tamatie en komkommer plante alvorens verdere navorsing gedoen is nie. Skedulering tot wateronttrekkingsvlakke vir groot sakke word egter geregverdig deur die verbeterde of gehandhaafde opbrengste van kweekhuis komkommers en tamaties. Die beraamde laagste onttrekkingsvlakke vir groot sakke wat nie opbrengs betekenisvol sal beïnvloed nie is 85% vir tamaties en 70% vir komkommers. Ten slotte dui die resultate duidelik daarop dat die gebruik van kapasitansie sensors in groot plantsakke besproeiingsbestuur van hidroponiese komkommers en tamaties in kokosveen verbeter deur oorbesproeiing uit te skakel en die watergebruiksdoeltreffendheid te verbeter. Meer navorsing is nodig alvorens ’n gevolgtrekking gemaak kan word ten opsigte van besproeiingskedulering met kapasitansie sensors in klein plantsakke.

In higher plants a massive conversion of the storage lipid to carbohydrate takes place in germinating seedlings. The conversion involves β-oxidation, the glyoxylate cycle and gluconeogenesis. The key glyoxylate cycle enzymes isocitrate lyase (ICL) and malate synthase (MS) are co-ordinately synthesised to high levels during germination and decline thereafter to undetectable levels. The enzymes reappear at the final stage of the growth, in senescent tissues. In this study the synthesis of other enzymes involved in the conversion of lipid to carbohydrate was investigated to determine if they are co-ordinately synthesised with ICL and MS, and whether the genes encoding them are subject to the same control of expression. Full length cDNA clones encoding glyoxysomal malate dehydrogenase (gMDH) and phosphoenolpyruvate carboxykinase (PEPCK) have been isolated from a Cucumis sativus senescent cotyledon cDNA library. gMDH is one of the glyoxylate cycle enzymes, and PEPCK is a key enzyme for gluconeogenesis, which had not previously been cloned from plants. The cDNA and predicted amino acid sequence of gMDH show very high homology (94% and 97% respectively) with watermelon counterparts. The amino acid sequence deduced from the cDNA encoding PEPCK shows 43 to 57% identity with bacterial, yeast and trypanosome enzymes, and includes a conserved ATP-binding domain. The sequence of a full length cDNA predicts a polypeptide of 74,397 Da. The cDNA was expressed in Escherichia coli and antibodies raised to the resultant protein. The cucumber genome was shown to contain single genes encoding gMDH and PEPCK, the expression of which was investigated by northern and western blotting.

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Conselho Nacional de Pesquisa e Desenvolvimento Científico e Tecnológico - CNPq
Cucumber crop has its production affected by the attack of the aphid Aphis gossypii Glover (Hemiptera: Aphididae), which colonizes the plant throughout all developmental stages. The use of chemical insecticides to control it has generated serious problems such as the emergence of resistant populations to the active ingredients used. This work aimed to evaluate fungus preparations based on entomopathogenic to control this insect pest in cucumber plants, and develop an insecticide the base of Beauveria bassiana (Bals.) Vuill. Under laboratory conditions, the three most promising isolates were tested, CG 864, PL 63 and IBCB 66,with five concentrations of conidia (1x105, 1x106, 1x107, 1x108 and 1x109 conidia / ml) and control (sterile water + Tween 80) . In the third stage of the experiments studies were conducted involving two preparations of biological insecticide: a) an aqueous suspension [pure conidia of B. bassiana 864 CG + 0.01% Tween 80; used as a standard] b) formulation of oil dispersion [conidia pure vegetable oil emulsifiable +] CG 864 isolated, and diluted with water for spraying the concentrations of 0.5; 1; 2 and 4% oil. The fungus preparations were standardized to have 1.0 x 107 spores / mL in applied spray. Isolates of the fungus B. bassiana were more virulent aphid A. gossypii that isolates Metarhizium anisopliae (Metschn.) Sorok. and Lecanicillium longisporum (Zimmerman) Zare & Gams. The isolates CG 864, IBCB 66 and PL 63 of the B. bassiana were the most virulent. B. bassiana preparations reduced the aphid population A. gossypii, with control efficiencies of 52.3% to 83.8%, however, there was no difference in the pest population density between the oil dispersion and the aqueous suspension conidia.
A cultura do pepino tem sua produção afetada pelo ataque do pulgão Aphis gossypii Glover (Hemiptera: Aphididae), que coloniza a planta durante todo seu estágio fenológico. O uso de inseticidas químicos para seu controle tem gerado sérios problemas, como o surgimento de populações resistentes aos princípios ativos utilizados. Este trabalho teve por objetivo avaliar preparações à base de fungo entomopatogênico para controle desse inseto-praga em plantas de pepino e desenvolver um inseticida a base de Beauveria bassiana (Bals.) Vuill. Em condições de laboratório, os três isolados mais promissores CG 864, PL 63 e IBCB 66, foram testados, com cinco concentrações de conídios (1x105; 1x106; 1x107; 1x108 e 1x109 conídios/mL) e a testemunha (água esterilizada +Tween 80). Foram realizados estudos envolvendo duas preparações do inseticida biológico: a) suspensão aquosa (conídios puros de B. bassiana CG 864 + Tween 80 a 0,01%), utilizada como padrão e b) formulação em dispersão oleosa [conídios puros + óleo vegetal emulsionável], do isolado CG 864, sendo diluída em água para pulverização nas concentrações de 0,5, 1; 2; 4; 8 e 16% de óleo. As preparações do fungo foram padronizadas para 1,0 x 107 conídios/mL na calda aplicada. Isolados do fungo B. bassiana foram mais virulentos ao pulgão A. gossypii que os isolados de Metarhizium anisopliae (Metschn.) Sorok. e Lecanicillium longisporum (Zimmerman) Zare & Gams. Os isolados CG 864, IBCB 66 e PL 63 de B. bassiana foram os mais promissores. Preparações de B. bassiana reduziram a população do pulgão A. gossypii, com níveis de eficiência de controle de 52,3% a 83,8%, porém, não houve diferença na densidade populacional da praga entre a dispersão oleosa e a suspensão aquosa de conídios.

O desenvolvimento da agricultura, a modernização dos meios dos cultivos, buscando atender a um mercado exigente, tem-se baseado no uso de insumos agrícolas para garantir a produção de alta qualidade e de quantidade. Tais culturas demandam o uso de pesticidas, cujos resíduos, principalmente em hortaliças e frutas, são motivo de preocupação com a saúde dos consumidores e de operários que necessitam retornar às culturas tratadas com esses agrotóxicos. Os objetivos deste estudo foram: a) estudar o comportamento dos resíduos de deltametrina, de diferentes formulações, em frutos, folhas e solo; b) avaliar os resíduos deslocáveis do inseticida nas folhas, como ponto de partida para estudos de exposição ocupacional; c) correlacionar os teores de deltametrina nos frutos com o controle da broca-das-cucurbitáceas e d) correlacionar os resíduos nos frutos com o limite máximo de resíduo (LMR) e o intervalo de segurança (período de carência) estabelecidos pela legislação. Os tratamentos foram: a) testemunha; b) três aplicações da formulação em concentrado emulsionável Decis 25 CE na dosagem de 30 mL p.c.100 L-1 de água (0,75 g i.a. deltametrina.100 L-1 de água); c) três aplicações da formulação em concentrado emulsionável Decis Ultra 100 CE na dosagem de 7,5 mL p.c.100 L-1 de água (0,75 g i.a. deltametrina.100 L-1 de água); e d) três aplicações da formulação em suspensão concentrada Decis 200 SC na dosagem de 3,75 mL de p.c.100 L-1 de água (0,75 g i.a. deltametrina 100 L-1 de água). As amostras de fruto e de solo foram colhidas a (-1); zero; 1; 3; 5 e 7 dias após a última aplicação; as amostras de folhas e as de para estudos de resíduos deslocáveis nestas foram tomadas a (-1); zero; 1; 3; 5; 7 e 14 dias. O método analítico constou da extração dos resíduos de deltametrina de acetato de etila, limpeza dos extratos por técnica de cromatografia de permeação em gel (GPC), com eluição feita com uma mistura de acetato de etila/ciclohexano. A determinação quantitativa por cromatografia de gás. Para a avaliação da eficiência do inseticida, foram feitas seis levantamentos de infestação, determinando-se a porcentagem de frutos brocados. Os resultados indicaram que os resíduos de deltametrina no fruto, embora em baixos níveis, encontravam-se acima do LMR (0,03 mg.kg-1), mesmo um dia após o término do intervalo de segurança (2 dias) para as formulações do inseticida. Nas folhas, os resíduos resultantes das aplicações da formulação SC foram sempre maiores do que ambas CE (10-20 vezes), sendo de 15-80 vezes mais altas do que nos frutos. No solo, os resíduos foram também baixos (0,01-0,05 mg.kg-1), e semelhantes nas três formulações, entretanto, com baixa dissipação. Os resíduos deslocáveis de deltametrina nas folhas foram muito elevados quando de aplicações em SC, comparadas com as formulações CE (4-20 vezes), com valores de meias-vida de 2,8; 3,8 e 32,2 dias, respectivamente para as formulações Decis 25 CE, Decis Ultra 100 CE e Decis 200 SC. O inseticida, nas formulações em que foi aplicado, foi eficiente no controle da praga durante todo o período de avaliação.
The agriculture development, the modernization of cultivation means, trying to meet a demanding market, has been based on the use of agricultural supplies to assure a high quality and quantity production. Such crops demand the use of pesticides, whose residues, especially in fruit and vegetable production, raise worries about the consumers’ health and of the workers who need to return to the treated crop with these pesticides. The objectives of this study were: a) to study the behavior of deltamethrin residues applied in different formulations in fruits, leaves and soil; b) to evaluate the dislodgeable residues of the insecticide in leaves, as a starting point for occupational exposure studies; c) to correlate deltamethrin concentration in fruit with the pickleworm control and d) to correlate residues in fruit with the maximum residue level (MRL) and the safety interval established by the legislation. The treatments were: a) control ; b) three applications of the emulsifiable concentrate formulation Decis 25 CE.100-1 at the dosage of 30 mL of c.p.100 L-1 water (0.75 g a.i. deltamethrin.100L-1 water); c) three applications of the emulsifiable formulation of Decis Ultra 100 CE at the dosage of 7.5 mL of p.c.100 L-1 water (0.75 g a.i. deltamethrin.100. L-1 water) and d) three applications of the concentrate suspension formulation Decis 200 SC at the dosage of 3.75 mL of c.p.100.L-1 water (0.75 g a.i. deltamethrin 100L-1 water). The fruit and soil samples were taken at (-1); zero; 1; 3; 5 and 7 days after the last application; leaf samples and also those for the studies of dislodgeable residues on them were collected at (-1); zero; 1; 3; 5; 7 and 14 days after the last application. The analytical method consisted of the extraction of deltamethrin residues in ethyl acetate, clean-up of the extracts by gel permeation chromatography (GPC), with elutition made with a mixture of ethyl acetate/cyclohexane. The quantitative determination was made by gas chromatograph. To evaluate the insecticide efficacy six infestation surveys were carried out, based on the percentage of infested fruit . The results indicate that the deltamethrin residues in fruit, though in low levels, were found higher than the MRL (0.03 mg.kg-1), for the three insecticide formulations, even a day after the end of the safety interval (2 days). In the leaves the resulting residues of the applications of SC formulation were always bigger than both CE (10-20 times), being 15-80 times higher in the fruits. In the soil, the residues were also low (0.01-0.05 mg kg-1), and similar in the three formulations, however with low dissipation. The dislodgeable residues of deltamethrin in leaves were higher in SC as compared to both CE (4-20 times), with half-life values of 2.8; 3.8 and 32.2 days, respectively for the formulation Decis 25 CE, Decis Ultra 100 CE and Decis 200 SC. The insecticide in the formulations applied was efficient in the pest control during the whole evaluation period.

Downy mildew, a foliar disease caused by the oomycete Pseudoperonospora cubensis (Berk. and Curt.) Rostow. is one of the most destructive pathogens of cucurbits. Resistant cultivars are available but nevertheless yield losses are high in North Carolina and Poland if fungicides are not used. The first objective of this experiment was to test all available plant introduction accessions from the U.S. National Plant Germplasm System of cucumber for downy mildew resistance under field conditions. The 1289 cultigens were tested at Clinton NC, USA, and Skierniewice, Poland during 2005-2007 under natural field epidemics of the disease. Averaged over locations, eighty-one cultigens were classified as highly resistant, 130 as moderately resistant, 406 as intermediate, 408 as moderately susceptible, and 271 as highly susceptible. The 40 most resistant and 10 most susceptible cultigens from these field trials, were further evaluated in replicated field and greenhouse experiments in North Carolina, along with 22 check cultivars. Results from the retest study in North Carolina confirmed the results of the initial screening study, although the range of downy mildew ratings in the North Carolina field retest were much narrower compared with the screening results obtained in the larger study. The most resistant and most susceptible lines in the screening study were also the most resistant and most susceptible lines in the field retest. The most resistant 10 cultigens averaged over both locations were Ames 2353, Ames 2354, PI 197085, PI 197088, PI 234517, PI 321008, PI 330628, PI 432878, PI 605996 and PI 618931. These cultigens originated from India, the United States, Pakistan, P.R. China and Taiwan. Despite the identification of resistant plant introduction accessions, they were not significantly better than the most resistant cultivars currently used in either North Carolina or Poland. The most positive aspect of the screening effort was that resistant plant introductions originated from diverse geographic regions. Because geographic diversity is often associated with genetic diversity in germplasm collections, the newly identified resistant typed may carry unique alleles as compared to commercial material. If so, then the potential exists to develop recombinant types from crosses of commercial by exotic materials which may be more resistant. The second objective of this study was to measure the correlation of four response traits. A low correlation among the four response traits on a diverse array of cucumber cultigens would suggest that the traits are controlled by different genes. Field studies were conducted to measure the response traits of plant stunting, leaf necrosis, chlorosis and sporulation caused by downy mildew infection. Each of the four traits were measured on 67 diverse cucumber cultigens in North Carolina and India. All cucumber cultigens were tested in four replications and two locations under natural field epidemics of the disease. A significant genotype by location interaction was found by analysis of variance and data from the two locations were analyzed separately. In North Carolina, necrosis and chlorosis were highly correlated (r=0.90) while sporulation was moderately correlated with necrosis and chlorosis(r=0.71 and r=0.70, respectively) and not significantly correlated with stunting. Stunting was moderately correlated with necrosis and chlorosis (r=0.43 and r=0.34, respectively). In India, chlorosis and sporulation were highly correlated (r=0.97) while necrosis was moderately correlated with chlorosis, sporulation and stunting (r=0.67 and r=0.0.65 and r=0.76, respectively). Stunting was moderately correlated with chlorosis and sporulation (r=0.55 and r=0.57, respectively). Sporulation or necrosis may be controlled by a different gene(s) but another year of testing is required. Stunting may also be controlled by a different gene(s) but difficulties in differentiating between stunting resulting from genotype and stunting resulting from disease must be resolved. Different degrees of correlation among chlorosis, necrosis and sporulation in North Carolina and India may be due to the presence of different races in the two locations. These differences may also be explained by the variable number and timing of ratings between the two locations. Availability of only one set of data for sporulation in North Carolina may have reduced the correlation between it and necrosis and chlorosis. Sporulation ratings need to be taken on a weekly basis rather than once during the last rating. Therefore, the possibility exists that chlorosis, necrosis and sporulation are response traits controlled by the same genes.

The glyoxylate cycle is known to take part in the net conversion of storage lipids to sugar germinating oilseeds. Two enzymes are exclusive for this cycle, malate synthase (MS) and isocitrate lyase (ICL) and their synthesis is coordinately regulated. These enzymes are active during postgerminative growth of seeds but are repressed in mature plants. However, they appear again when plants senesce. Genes for both enzymes are regulated by carbohydrate status. The aim of this study was to examine carbohydrate regulation. Expression of Ms and Icl genes in cucumber roots was low but increased upon excision and dark-incubation during a six day period in the absence of exogenous sugar. However, when sucrose was added to the incubation medium their expression was repressed. Hairy roots obtained using Agrobacterium rhizogenes strain A4 showed the same pattern of expression. Transgenic hairy roots containing Ms and Icl promoters fused to the GUS reporter gene, had a low level of GUS activity. This GUS activity increased dramatically when roots were excised and incubated in the absence of sugar, indicating regulation at the transcriptional level. Histochemical staining showed that GUS activity is concentrated in root tips and lateral root primordia where demand for carbohydrate is presumably greatest. Defoliation and shading experiments were carried out to examine the expression of Ms and Icl in roots of whole plants under natural conditions. In both cases, MS and ICL mRNA increased and roots showed a decline in sugar content. Thus, indication of Ms and Icl expression takes place in roots when supply of carbohydrate from the shoot is impaired. Results are consistent with the hypothesis that gene expression in the roots is controlled by carbohydrate supply from the shoot. Identification of regulatory elements in the Icl promoter required for the sugar response were made possible using transgenic cucumber hairy roots. Deletions of the Icl gene were assayed, which located a 200 bp region necessary for the sugar response more than 1 kbp upstream of the transcriptional start.

Thesis (MTech (Horticulture))--Cape Peninsula University of Technology, 2012.
The effects of various water quantities were assessed on Cucumber (Cucumis sativa L.) grown hydroponically in the greenhouse. The objectives of the study were to evaluate influence of water quantities on: i) photosynthesis and chlorophyll content of Cucumis sativa L.; ii) the nutrient uptake in Cucumis sativa L. iii) flavonoid and anthocyanin metabolism in Cucumis sativa L. and iv) growth and yield in Cucumis sativa L. The treatments included 8 various water regimes (21/h, 41/h, 61/h, 81/h, 101/h, 121/h, 141/h and 161/h. The plants received water five times a day, making it 10, 20, 30, 40, 50, 60, 70, and 80 litres per day. Results showed that generally the Photosynthetic rate (A), intercellular CO2 concentration (Cj) and stomata conductance (gs) and the transpiration rate of the cucumber plants were significantly increased by increasing water quantities compared with lower water quantities. Additionally, there were significant improvements in leaf colour in weeks 2, 3, 4, 5, 6, 7 and 8. Overall, the foliage colour was improved as water supply was increased. The greener leaves were documented in treatments supplied with higher water doses. Additionally, the chlorophyll content of cucumber plants was increased significantly with varying water quantities. The highest chlorophyll contents were found in plants treated with 161/h.

Weed Control in Cucumber Cucumis sativus, Pumpkin Cucurbita maxima, and Summer Squash Cucurbita pepo with Halosulfuron By Brian Wayne Trader (Abstract) Cucumber (Cucumis sativus L.), pumpkin (Cucurbita maxima Duch. ex Lam.), and summer squash (Cucurbita pepo L.) are economically important crops in Virginia. Only a few herbicides are registered for weed control in these crops. Halosulfuron is a sulfonylurea herbicide which controls several broadleaf weeds and yellow nutsedge (Cyperus esculentus L.). Cucurbit crops have some tolerance to this herbicide. The efficacy of halosulfuron for control of several weed species and tolerance of four vine crops to halosulfuron were investigated in field and greenhouse studies in 1999, 2000, and 2001. In the field, halosulfuron was applied to cucumber, pumpkin, zucchini squash, and yellow summer squash at 4, 9, 18, and 27 g ai/ha preemergence (PRE) and postemergence (POST) in combination with clomazone at 174 g ai/ha plus ethalfluralin applied PRE at 630 g/ha. Crop injury, weed control, and crop yield was collected from the field studies. Weed control by halosulfuron was dependent upon application method. Halosulfuron applied preemergence controlled only common ragweed (Ambrosia artemisiifolia L.) and smooth pigweed (Amaranthus hybridus L.). Postemergence halosulfuron controlled common ragweed, smooth pigweed, morningglory species (Ipomoea spp.), yellow nutsedge, and rice flatsedge (Cyperus iria L.). All four crops treated with halosulfuron produced yields equal to or higher than the crops receiving clomazone and ethalfluralin alone or the hand-weeded check. In the greenhouse, tolerance of cultivars of each crop to halosulfuron was investigated with the same rates applied in the field. Cultivars responded similar to postemergence halosulfuron applications with respect to fresh and dry weights in all four crops. The response of several populations of acetolactate synthase inhibiting (ALS) resistant smooth pigweed to postemergence halosulfuron was also investigated. Halosulfuron activity against ALS-inhibitor resistant smooth pigweed was population dependent. In the greenhouse, postemergence halosulfuron at the same rates used in the field studies controlled yellow nutsedge.
Master of Science

Thesis submitted in fulfilment of the requirements for the degree Master of Technology: Horticulture in the Faculty of Applied Sciences at the Cape Peninsula University of Technology, 2012
The effects of various water quantities were assessed on Cucumber (Cucumis sativa L.) grown hydroponically in the greenhouse. The objectives of the study were to evaluate influence of water quantities on: i) photosynthesis and chlorophyll content of Cucumis sativa L.; ii) the nutrient uptake in Cucumis sativa L. iii) flavonoid and anthocyanin metabolism in Cucumis sativa L. and iv) growth and yield in Cucumis sativa L. The treatments included 8 various water regimes (2l/h, 4l/h, 6l/h, 8l/h, 10l/h, 12l/h, 14l/h and 16l/h. The plants received water five times a day, making it 10, 20, 30, 40, 50, 60, 70, and 80 litres per day. Results showed that generally the Photosynthetic rate (A), intercellular CO2 concentration (Ci) and stomata conductance (gs) and the transpiration rate of the cucumber plants were significantly increased by increasing water quantities compared with lower water quantities. Additionally, there were significant improvements in leaf colour in weeks 2, 3, 4, 5, 6, 7 and 8. Overall, the foliage colour was improved as water supply was increased. The greener leaves were documented in treatments supplied with higher water doses. Additionally, the chlorophyll content of cucumber plants was increased significantly with varying water quantities. The highest chlorophyll contents were found in plants treated with 16l/h. The fresh and dry weights of roots, leaves and stems were significantly (P≤0.001) influenced by different water quantities supplied to Cucumis sativa L. The largest quantity of fresh roots was recorded in the control treatment (2l/h) in comparison with all other treatments. However, the best growth with regard to fresh and dry weights of leaves and stems were recorded by supplying the water quantities ranging from 10-16l/h. Altering water supply significantly (P≤0.001) affected the uptake of nitrogen, phosphorous, potassium, calcium, sodium, copper, zinc, aluminium and iron in roots of Cucumis sativa L. Irregular results were recorded in the uptake of these nutrients in the roots. However, leaf uptake of N, P, K, Ca, magnesium, sulphur, Cu, Zn, manganese, boron, and Al responded significantly (P≤0.001) to the different water quantities. The best result for each was observed at quantities involving 16l/h. In stems of cucumber water quantities significantly (P≤0.001) affected the uptake of N, P, K, Ca, Mg, Na, S, Cu, Zn, Mn and B. The highest uptake of N, P, Ca, Mg and S were found at the maximum supply of water (16l/h) compared with the control (2l/h). Sodium uptake showed irregular patterns, whereas K and Zinc uptake peaked at 14l/h. The data from this study showed that flavonoid metabolism was not significantly affected by the different water quantities supplied to cucumber plants. However, the anthocyanin content in roots, leaves, and stem was significantly influenced by water levels. The lowest water quantity (2-6l/h) significantly increased the levels of anthocyanins in all tissues tested. Increasing water quantities significantly decreased the anthocynanin metabolism in all tissues. Plant height displayed significant differences with water quantities from weeks 1-8. In week 1, the plant height was superior at supplying 4l/h in comparison with other treatments. In week 2 and 5 irregular trends were detected. At weeks 3 and 4, plants supplied with 8-12l/h displayed superior plant height performance. At weeks 7-8, significant and optimal results were observed at water quantities ranging from 4-16l/h compared with the control treatment. Water quantities significantly (P≤0.001) affected the number of leaves per plant from weeks 2-8. Irregular results were displayed in weeks 2 and 3. At weeks 4 and 5, the highest numbers of leaves were in water quantities of 12l/h and 10l/h, respectively. Generally, leaf numbers increased with increasing water levels from weeks 6-8. Plant vigour was significantly affected by the alteration of water quantities at weeks 1, 2, 4, 5, 6, 7 and 8. At weeks 1 and 4, more vigorous plants were found in the treatments that received from 10-16 l/h. At weeks 2 and 5, optimal results were found at treatments that received from 6-14l/h. At weeks 6, 7 and 8, the most vigorous plants were found at the highest water quantity of 16l/h. With fruit length, fruit width, rind colour, fruit quality (marketable fruit) and weight, results from the harvest done in the first, second and third week showed that water quantities significantly influenced these parameters. Optimal results were reported when the plants were supplied with water ranging between 14-16l/h. During harvesting at week 4, the fruit length, width, rind colour, were of marketable quality at 16l/h. Generally, the plants that received highest amount of water (16l/h) had the highest cucumber yields compared with all other treatments. Higher water quantities in this study resulted in increased physiological responses such as photosynthesis and nutrient uptake which resulted in the higher fruit yields. In water-limited environments, results from this study could assist growers with reasonable cucumber yields while saving water for other farm uses.

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior
Aluminum (Al) is the most abundant metal in the Earth's crust, affecting growth and development of plants. The aim of this study was to investigate the effects of Al on seedlings of cucumber (Cucumis sativus L.) and oat (Avena sativa L) through the analysis of biochemical and physiological parameters. Three different genotypes of oat seedlings were studied, namely UFRGS 930598 Al-sensitive, UFRGS 17 Altolerant, and 280 Al-intermediate (resulting from the crossing UFRGS 930598 and UFRGS 17), exposed to 0, 5, 10, 20, and 30 mg/L Al. The biochemical parameters analyzed for cucumber were: the activity of antioxidant enzymes (catalase (CAT), ascorbate peroxidase (APX) and superoxide dismutase (SOD)), the levels of lipid peroxidation, leakage electrolytes, protein oxidation, and chlorophyll content. The increase of electrolyte leakage and the production of hydrogen peroxide observed are related to the decreased efficiency of the antioxidant system at the highest concentrations of Al. The antioxidant system was unable to prevent the toxicity resulting in negative effects such as lipid peroxidation, protein oxidation, and decreased plant growth. Oat seedlings were exposed to Al in different growth media. The first exposure was in the midst of semi-solid growth agar for 5 days, seedlings with five days of development and then to a hydroponic solution for 7 days with 10 days of seedling development. The content of hydrogen peroxide, lipid peroxidation, ascorbic acid and non-protein thiols (NPSH), as well as the activity of the enzymes CAT, APX and SOD, and the content of Al accumulated in the seedlings were evaluated. Enzymes activities of the antioxidant SOD and CAT were increased in UFRGS 17 and UFRGS 280 genotypes. Even when these two genotypes accumulated high concentrations of Al, they did not show high levels of lipid peroxidation and contents of hydrogen peroxide when compared with the 930598 genotype. For this genotype, an activation of the enzyme APX was observed, however, high levels of Al accumulated in the plant caused an increase in the lipid peroxidation and hydrogen peroxide content. The UFRGS 930598 genotype was more sensitive to Al than the UFRGS 17 and UFRGS 280 genotypes, which confirms the previous morphological analysis obtained by FEDERIZZI et al., 2000. Although there was increased activity of APX in this genotype, the antioxidant system was not efficient in the removal of reactive oxygen species (ROS). In order to better understand these results, a growth medium with a hydroponic solution was used in which the mobility of the metal was greater for an exposure period of 7 days with oat seedlings with 10 days of development. Besides the biochemical parameters mentioned above, the analysis of the growth of roots and shoots, fresh and dry matter, chlorophyll content, activity of the enzyme δ -aminolevulinic acid dehydratase (δ -ALA -D), and the monitoring of the pH of the hydroponic solution of each genotype were performed. The pH of the hydroponic solution of salt-tolerant genotype (UFRGS 17) showed a significant increase in pH, while the sensitive (UFRGS 930598) and intermediate (UFRGS 280) genotypes showed no significant changes. The sensitive genotype presented inhibition of root and shoot growth at the highest concentrations of Al while the tolerant and intermediate genotype showed no significant changes. The activity of antioxidant enzymes was increased after 7 days of exposure to Al in the sensitive genotype, whereas in the tolerant genotype there was no increase in this activity. In seedlings of the intermediate genotype there was an increase in the activity of CAT, APX and SOD enzymes only at higher Al concentrations (20 and 30 mg/L). Results showed that the intermediate and tolerant genotypes showed similar effects not only on the activity of enzymes of the antioxidant system, but also on the physiological parameters such as growth of roots and shoots. Even when accumulating high concentrations of Al, the intermediate genotype did not show a decrease in growth, which shows that it has resistance mechanisms related to the internal immobilization of this metal in the vacuoles. The tolerant genotype also introduces mechanisms of resistance to Al, but these mechanisms may be the exclusion of Al by binding this metal to organic acids. In order to investigate if the antioxidant system is activated in different genotypes of oat, seedlings were placed in growth medium with a hydroponic solution and withdrawn from the medium after 12, 24, and 36 h of exposure to 20 mg/L. Tolerant and intermediate genotypes showed an increase of the enzyme activity of the antioxidant system after 12 h of exposure to Al, while the sensitive genotype presented this increase only after 24 or 36 h. This difference in the rate of activation of the antioxidant system may be crucial in maintaining cellular redox homeostasis of this genotype. At this stage of development, the tolerant and the intermediate genotypes showed a stimulation of root growth while the sensitive type showed significant growth retardation. In order to compare plant species, cucumber was placed in hydroponic growth medium with the oat seedlings (sensitive and tolerant genotypes.) When cucumber was placed in hydroponic solution exposed to 20 mg/L Al along with the tolerant (UFRGS 17) and the sensitive (UFRGS 930 598) genotypes, it showed similarities with the sensitive genotype (increased catalase activity after 36 h of exposure to Al). The levels of lipid peroxidation were high after 12, 24, and 36h of exposure to Al and as a consequence there was a reduction in root growth. Considering the evaluation with tolerant (UFRGS 17) and sensitive (UFRGS 930 598) oat genotypes, the cucumber may be considered an Al-sensitive species.
O alumínio (Al) é o metal mais abundante na crosta terrestre, afetando o crescimento e desenvolvimento das plantas. Neste estudo, foram investigados através da análise de parâmetros bioquímicos e fisiológicos, os efeitos do alumínio (Al) em plântulas de pepino (Cucumis sativus L.) e em plântulas de aveia (Avena sativa L). As plântulas de aveia estudadas pertencem a três diferentes genótipos: UFRGS 930598-sensível ao alumínio, UFRGS 17-tolerante ao alumínio e UFRGS 280-intermediário ao alumínio (resultante do cruzamento entre UFRGS 930598 e UFRGS 17), expostos a 0, 5, 10, 20 e 30 mg/L de Al. Os parâmetros bioquímicos analisados para C. sativus foram: a atividade das enzimas antioxidantes (catalse (CAT), ascorbato peroxidase (APX) e superóxido dismutase (SOD)), os níveis de peroxidação lipídica, vazamento de eletrólitos, oxidação de proteínas e conteúdo de clorofila. O aumento na porcentagem de vazamento de eletrólitos e na produção de peróxido de hidrogênio observado está relacionado com a diminuição da eficiência do sistema antioxidante nas concentrações mais altas de alumínio. O sistema antioxidante foi incapaz de impedir a toxicidade, resultando em efeitos negativos, tais como peroxidação lipídica, oxidação de proteínas e diminuição do crescimento das plantas. Plântulas dos três genótipos de aveia foram expostas ao Al em diferentes meios de crescimento. Primeiro a exposição foi em meio de crescimento semi-sólido com agar por 5 dias, com plântulas com 5 dias de desenvolvimento, depois em solução hidropônica por 7 dias com plântulas com 10 dias de desenvolvimento. Foram avaliados o conteúdo de peróxido de hidrogênio, peroxidação de lipídeos, conteúdo de ácido ascórbico e tióis não protéicos (NPSH), a atividade das enzimas CAT, APX e SOD e o conteúdo de Al acumulado nas plântulas. As enzimas do sistema antioxidante SOD e CAT tiveram suas atividades aumentadas nos genótipos UFRGS 17 e UFRGS 280. Mesmo acumulando altas concentrações de alumínio estes dois genótipos não apresentaram altos níveis de peroxidação lipídica e conteúdo de peróxido de hidrogênio quando comparados com o genótipo 930598. Para esse genótipo houve ativação da enzima APX, entretanto os altos níveis de alumínio acumulados na planta causaram um aumento na peroxidação de lipídeos e no conteúdo de peróxido de hidrogênio. O genótipo UFRGS 930598 mostrou ser mais sensível ao alumínio que os genótipos UFRGS 17 e UFRGS 280, o que confirma as análises morfológicas prévias obtidas por FEDERIZZI et al., 2000. Embora tenha ocorrido um aumento da atividade da APX neste genótipo, o sistema antioxidante não foi eficiente na remoção das espécies reativas de oxigênio (EROS). Com a finalidade de melhor entender esses resultados foi utilizado o meio de crescimento com solução hidropônica onde a mobilidade do metal é maior por um período de exposição de 7 dias com plântulas de aveia com 10 dias de desenvolvimento. Neste experimento além dos parâmetros bioquímicos citados acima, foi feita a análise do crescimento da raiz e parte aérea, matéria seca e fresca, conteúdo de clorofila, atividade da enzima δ -aminolevulinato desidratase (δ-ALA-D) e o monitoramento do pH da solução hidropônica de cada genótipo. O pH da solução hidropônica do genótipo tolerante (UFRGS 17) apresentou um aumento significativo nos valores de pH, enquanto os genótipos sensíveis (UFRGS 930598) e intermediário (UFRGS 280) não apresentaram mudanças significativas nos valores de pH. O genótipo sensível teve inibição do crescimento da raiz e parte aérea nas concentrações mais altas de alumínio enquanto que para o genótipo tolerante e intermediário, não houve modificações significativas do crescimento da raiz e parte aérea. A atividade das enzimas antioxidantes foi aumentada após 7 dias de exposição ao alumínio no genótipo sensível, enquanto que no genótipo tolerante não houve aumento na atividade das enzimas antioxidantes. Nas plântulas do genótipo intermediário houve o aumento na atividade das enzimas CAT, APX e SOD apenas nas maiores concentrações de alumínio (20 e 30 mg/L). Os resultados mostram que os genótipos intermediário e tolerante apresentaram semelhanças quanto ao efeito do alumínio na atividade das enzimas do sistema antioxidante e também nos parâmetros fisiológicos como o crescimento das raízes e parte aérea. Mesmo acumulando altas concentrações de alumínio, o genótipo intermediário não apresentou diminuição do crescimento, o que mostra que ele apresenta mecanismos de resistência, relacionado com a imobilização interna deste metal nos vacúolos. O genótipo tolerante também apresenta mecanismos de resistência ao alumínio, porém estes mecanismos podem ser de exclusão do alumínio pela raiz através da ligação deste metal a ácidos orgânicos. Com a finalidade de investigar quando o sistema antioxidante é ativado nos diferentes genótipos de aveia, as plântulas foram colocadas no meio de crescimento com solução hidropônica e retiradas do meio após 12, 24 e 36 horas de exposição a 20 mg/L de Al. Os genótipos tolerante e intermediário apresentaram aumento na atividade das enzimas do sistema antioxidante após 12 h de exposição ao alumínio, enquanto o genótipo sensível somente após 24 ou 36 horas de exposição. Esta diferença na velocidade de ativação do sistema antioxidante pode ser crucial na manutenção da homeostase celular redox deste genótipo. Nessa fase do desenvolvimento, o genótipo tolerante e o intermediário apresentaram um estímulo do crescimento da raiz enquanto o sensível um atraso do crescimento. Com a finalidade de estabelecer comparações entre as espécies vegetais, o pepino (Cucumis sativus) foi colocado em meio de crescimento hidropônico, juntamente com as plântulas de aveia (genótipo sensível e tolerante). O pepino (Cucumis sativus) quando colocado em solução hidropônica exposto a 20 mg/L de alumínio juntamente com o genótipo tolerante (UFRGS 17) e o genótipo sensível (UFRGS 930598), apresentou semelhanças com o genótipo sensível tais como o aumento da atividade da enzima catalase após 36 h de exposição ao alumínio. Os níveis de peroxidação lipídica foram elevados após 12, 24 e 36h de exposição ao alumínio e como conseqüência a raiz teve uma diminuição do crescimento. Através da avaliação conjunta, com os genótipos de aveia tolerante, UFRGS 17, e sensível, UFRGS 930598, o pepino (Cucumis sativus) pode ser considerado uma espécie sensível ao alumínio.

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A agricultura familiar é representativa em termos de produção agrícola e otimização da utilização do solo, contribuindo significativamente para a oferta nacional de alimentos e matéria-prima, sendo responsável por grande parte da geração de emprego e renda na área rural. Essa capacidade produtiva pode ser observada nos produtores familiares assentados que, além de produzirem para subsistência, possuem potencial para geração de excedentes. Entretanto, ainda existem gargalos que impedem o aproveitamento deste potencial, como dificuldade de acesso a assistência técnica, linhas de crédito de custeio e aquisição de máquinas e implementos, mercado de seguro rural ainda restrito, entre outros. Na contramão dessa problemática, pode-se identificar produtores rurais, como os do Assentamento Reunidas, que buscam ser competitivos, adotando melhores tecnologias de produção. A partir de um acompanhamento detalhado dos custos de produção junto a alguns produtores familiares assentados foi possível identificar potencialidades técnicas e econômicas destes produtores. O presente trabalho objetivou realizar uma análise econômica da produção de pepino tipo alongado, na exploração em campo aberto e em estufa para identificar a viabilidade desta atividade dentro do assentamento. As duas técnicas de cultivo diferenciamse em termos técnicos. A renda obtida nestas atividades foi comparada com a classificação proposta para a agricultura familiar e observou-se que, dos produtores familiares assentados que participaram do estudo, um foi classificado como produtor familiar capitalizado e quatro foram classificados como produtores familiares em vias de capitalização. Os resultados obtidos mostraram que os produtores familiares assentados possuem potencial para serem competitivos a partir das atividades desenvolvidas dentro de seus lotes...
The familiar agriculture is representative in terms of agricultural production and optimization of the soil utilization, it contributes significantly to the national offer of food and it is responsible for a great part of job creation and income in the rural area. This productive capacity may be observed in the settled familiar producers, who besides produce to the subsistence might have a great potential to creation of the excess. Nevertheless, there are still bottlenecks that obstruct the utilization of this potential, as a difficulty of the access to the technical assistance, cost line of credit and acquisition of machines and implements, market of rural insurance still restricted, among other things. Against this problematic, we can indentify rural producers, as in Assentamento Reunidas, who search to be competitive, adopting better technologies of production. Through a detailed follow-up of the production costs together some of the settled familiar producers, it was possible to identify the technical and economical potentialities of these products. Thus, this work aimed to accomplish an economic analysis of the production of cucumber in the exploration in open field and in the greenhouse to indentify the viability of this activity inside the settling. The two techniques of cultivation are different in technical terms. The gained income in these activities was compared with the classification propose to the familiar agriculture and it was observed that among the settled familiar producers, who participated of this study, one of them was classified as the capitalized producer and four of them were classified as the familiar producers in the way to capitalization. The obtained results present that the settled familiar producers owe a potential to be competitive through the developed activities inside their lots. The control of the costs is primordial to the profitability...(Complete abstract click electronic access below)

Resumo: A agricultura familiar é representativa em termos de produção agrícola e otimização da utilização do solo, contribuindo significativamente para a oferta nacional de alimentos e matéria-prima, sendo responsável por grande parte da geração de emprego e renda na área rural. Essa capacidade produtiva pode ser observada nos produtores familiares assentados que, além de produzirem para subsistência, possuem potencial para geração de excedentes. Entretanto, ainda existem gargalos que impedem o aproveitamento deste potencial, como dificuldade de acesso a assistência técnica, linhas de crédito de custeio e aquisição de máquinas e implementos, mercado de seguro rural ainda restrito, entre outros. Na contramão dessa problemática, pode-se identificar produtores rurais, como os do Assentamento Reunidas, que buscam ser competitivos, adotando melhores tecnologias de produção. A partir de um acompanhamento detalhado dos custos de produção junto a alguns produtores familiares assentados foi possível identificar potencialidades técnicas e econômicas destes produtores. O presente trabalho objetivou realizar uma análise econômica da produção de pepino tipo alongado, na exploração em campo aberto e em estufa para identificar a viabilidade desta atividade dentro do assentamento. As duas técnicas de cultivo diferenciamse em termos técnicos. A renda obtida nestas atividades foi comparada com a classificação proposta para a agricultura familiar e observou-se que, dos produtores familiares assentados que participaram do estudo, um foi classificado como produtor familiar capitalizado e quatro foram classificados como produtores familiares em vias de capitalização. Os resultados obtidos mostraram que os produtores familiares assentados possuem potencial para serem competitivos a partir das atividades desenvolvidas dentro de seus lotes...(Resumo completo, clicar acesso eletrônico abaixo)
Abstract: The familiar agriculture is representative in terms of agricultural production and optimization of the soil utilization, it contributes significantly to the national offer of food and it is responsible for a great part of job creation and income in the rural area. This productive capacity may be observed in the settled familiar producers, who besides produce to the subsistence might have a great potential to creation of the excess. Nevertheless, there are still bottlenecks that obstruct the utilization of this potential, as a difficulty of the access to the technical assistance, cost line of credit and acquisition of machines and implements, market of rural insurance still restricted, among other things. Against this problematic, we can indentify rural producers, as in Assentamento Reunidas, who search to be competitive, adopting better technologies of production. Through a detailed follow-up of the production costs together some of the settled familiar producers, it was possible to identify the technical and economical potentialities of these products. Thus, this work aimed to accomplish an economic analysis of the production of cucumber in the exploration in open field and in the greenhouse to indentify the viability of this activity inside the settling. The two techniques of cultivation are different in technical terms. The gained income in these activities was compared with the classification propose to the familiar agriculture and it was observed that among the settled familiar producers, who participated of this study, one of them was classified as the capitalized producer and four of them were classified as the familiar producers in the way to capitalization. The obtained results present that the settled familiar producers owe a potential to be competitive through the developed activities inside their lots. The control of the costs is primordial to the profitability...(Complete abstract click electronic access below)
Orientador: Maura Seiko Tsutsui Esperancini
Coorientador: Osmar de Carvalho Bueno
Banca: Maria Inez Espagnoli Geraldo Martins
Banca: Elias José Simon
Mestre

Cucumber is one of the most important horticultural species at economic level. Despite its agronomic relevance, there is currently no efficient transformation method available. The problems to obtain transgenic cucumber plants are mainly due to the low morphogenetic response in explants of certain genotypes, poor adequacy of selection methods, decrease in regeneration rate as a consequence of the usual treatments in a transformation experiment and, above all, the high rate of 'escape' plants. Taking into account the existing problems, the first objective of the present work has been the evaluation of the morphogenetic response in cucumber explants and the development of regeneration methods potentially useful in transformation experiments. These studies have been carried out with two commercial cultivars, four pure lines and one line that has been frequently used in cucumber breeding programs. Different types of primary explants have been evaluated to determine which may be the most suitable in a transformation experiment. The influence of the ontogenic state of the seedling on the degree of myxoploidy in cotyledon explants has been studied. Likewise, the ploidy level of regenerated plants from these explants has been determined. Regarding the culture medium, the effect of growth regulators, as well as that of other components, such as silver nitrate or copper sulphate, has been studied. In the context of the second objective, studies on the different stages of the transformation process by co-cultivation of cucumber explants with Agrobacterium tumefaciens have been carried out. Several factors, such as the Agrobacterium strain, how to carry out the phases of inoculation and co-culture, the suitability of different marker genes in the selection process and the influence of different components of the culture medium have been analyzed. Attempts have also been made to infer the causes of the occurrence of 'escape' plants or the formation of chimeras in cucumber transformation experiments. Finally, based on the results obtained, some solutions that could help to avoid this problem in future experiments are proposed.
El pepino es una de las especies hortícolas más importantes a nivel económico. Pese a su relevancia agronómica, no puede decirse que a día de hoy se disponga de un método de transformación adecuado. Los problemas a la hora de conseguir plantas transgénicas de pepino estriban en la baja respuesta morfogenética en explantes de ciertos genotipos, la escasa adecuación de los métodos de selección, el descenso en la tasa de regeneración debido a los tratamientos habituales en un experimento de transformación y, sobre todo, la alta tasa de escapes. En función de la problemática existente, el primer objetivo del presente trabajo ha sido la evaluación de la respuesta morfogenética en explantes de pepino y el desarrollo de métodos de regeneración potencialmente útiles en experimentos de transformación. Estos estudios se han llevado a cabo con dos cultivares comerciales, cuatro líneas puras y una línea que ha sido utilizada frecuentemente en programas de mejora genética de pepino. Se han empleado distintos tipos de explantes primarios para determinar cuál o cuáles pueden ser los más adecuados en un experimento de transformación. Se ha estudiado la influencia del estado ontogénico de la plántula sobre el grado de mixoploidía en explantes de cotiledón. Asimismo, se ha determinado el nivel de ploidía de las plantas regeneradas a partir de estos explantes. Por lo que respecta al medio de cultivo, además de estudiar el efecto de componentes habituales (e.g. reguladores del crecimiento) se ha evaluado el de otros que no lo son tanto, como el nitrato de plata o el sulfato de cobre. En el contexto del segundo objetivo se han realizado una serie de estudios sobre las etapas del proceso de transformación mediante co-cultivo de explantes de pepino con Agrobacterium tumefaciens. Se han analizado diversos factores, tales como la cepa de Agrobacterium, la forma de llevar a cabo las fases de inoculación y co-cultivo, la adecuación de distintos genes marcadores en el proceso de selección y la influencia de distintos componentes del medio de cultivo. Asimismo, se han tratado de inferir las causas que generan la aparición de escapes o de quimeras en experimentos de transformación de pepino. Por último, sobre la base de los resultados obtenidos, se proponen algunas soluciones que podrían ayudar a evitar este problema en futuros experimentos.
El cogombre és una de les espècies hortícoles més importants a nivell econòmic. A pesar de la seua rellevància agronòmica, no pot dir-se que a hores d'ara es dispose d'un mètode de transformació adequat. Els problemes a l'hora d'aconseguir plantes transgèniques de cogombre consistixen en la baixa resposta morfogenètica en explants de certs genotips, l'escassa adequació dels mètodes de selecció, el descens en la taxa de regeneració degut als tractaments habituals en un experiment de transformació i, sobretot, l'alta taxa de fugues. En funció de la problemàtica existent, el primer objectiu del present treball ha sigut l'avaluació de la resposta en explants de cogombre i el desenvolupament de mètodes de regeneració potencialment útils en experiments de transformació. Estos estudis s'han dut a terme amb dos cultivars comercials de cogombre, tres línies pures i una línia que ha servit de base en programes de millora. S'han empleat distints tipus d'explants primaris per a determinar quin o quins poden ser els més adequats en un experiment de transformació. Pel que fa al mig de cultiu, a més d'estudiar l'efecte de components habituals (e.g. reguladors del creixement) s'ha avaluat el d'altres que no ho són tant, com el nitrat de planta o el sulfat de coure. Així mateix, s'ha analitzat el grau de mixoploidia en alguns explants i l'efecte de certs tractaments sobre el nivell de ploidia de les plantes regenerades. En el context del segon objectiu s'han realitzat una sèrie d'estudis sobre les etapes del procés de transformació per mitjà de co-cultiu d'explants de cogombre amb Agrobacterium tumefaciens. S'han analitzat diversos factors, com ara el cep d'Agrobacterium, la forma de dur a terme les fases d'inoculació i co-cultiu, l'adequació de distints gens marcadors en el procés de selecció i la influència de distints components del mig de cultiu. Així mateix, s'han tractat d'inferir les causes que generen l'aparició de plantes no transgèniques (escape plants) o de quimeres en experiments de transformació de cogombre. Finalment, sobre la base dels resultats obtinguts es plantegen algunes solucions que ajuden a evitar estos problemes en futurs experiments.
Fonseca Miguel, JA. (2017). Estudios sobre regeneración y transformación genética en pepino (Cucumis sativus L) vía Agrobacterium tumefaciens [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/90405
TESIS

Si è deciso di valutare il potenziale antinfiammatorio di un fitoestratto commerciale di Cucumis sativus L. in cani sottoposti ad intensa attività fisica. Per avere un quadro chiaro delle infiammazioni del tratto gastrointestinale in seguito ad intensa attività fisica ed eventuali loro variazioni dovute all’effetto benefico del trattamento, si è scelto di procedere con analisi metabolomica nelle feci sottoposte ad NMR, tenendo in considerazione i risultati delle analisi comparative tra cani sani e affetti da malattie croniche intestinali, basate sull’osservazione di mRNA di marcatori infiammatori caratterizzanti IBD. L'intenso esercizio provoca all'organismo diversi tipi di stress, come lo stress ossidativo, l'infiammazione a livello muscolare (Powers and Jackson 2008) e a livello gastrointestinale (Lambert et al., 2014). Il cortisolo è stato indicato come un importante indicatore di stati fisiologici alterati fortemente correlati allo stress (Beerda et al., 1996, 1998). Più recentemente uno studio ha dimostrato che, nei cani da valanga militari, l'esercizio influenzava l'espressione di geni coinvolti nel metabolismo e nello stress ossidativo, valutati in campioni di saliva (Diverio et al., 2014).Il seme del Cucumis sativus è un rimedio naturale che si è mostrato efficace per il trattamento del diabete mellito nei ratti (Minaiyan, Zolfaghari, & Kamal, 2011). Studi su modelli animali hanno dimostrato le proprietà antinfiammatorie della pianta senza provocare effetti collaterali (Uzuazokaro, Okwesili, & Chioma, 2015). Sono state campionate le feci di 9 cani rappresentative in sequenza temporale di riposo, attività di caccia senza trattamento, attività di caccia con fitoestratto CHG, nuovamente riposo. I risultati delle analisi sull'mRNA di marcatori infiammatori unitamente ai risultati di metabolomica emersi da analisi spettrofotometrica hanno permesso di evidenziare un potenziale effetto positivo del trattamento.

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior
The cucumber (Cucumis sativus L.) is a vegetable belonging to the family Cucurbitaceae, of great importance in Brazil. It is grown, preferentially in tropical climate, in high temperature conditions. It has a high economical, nourishing and social value because it generates direct or indirect jobs, requiring a labor demand from its cultivation to its commercialization. Due to the cultivation expression, the seed physiological and sanitary quality constitutes an important factor, being responsible for limitations in the product quality which is addressed to commercialization. So, with this work, one aimed at verifying the influence of Fusarium moniliforme on the seed physiological quality of two cucumber cultivars: Wisconsin and Caipira, through the hydric restriction inoculation technique, besides assessing the efficiency of the vigor tests for the stratification of the lots according to its physiological quality. The isolate of F. moniliforme was obtained from cucumber seeds. Each cultivar was divided into three lots of different physiological quality, differentiated by artificial aging. The treatments consisted in: Absolute witness; PDA + mannitol 0.8 Mpa; PDA pure; PDA + mannitol 0.8 Mpa + F.moniliforme; and PDA + F. moniliforme. The seed physiological quality was evaluated through tests carried out in laboratory conditions and in greenhouse. The hydric restraint was efficient to infect the seeds of two cultivars by pathogen, proving that this influences negatively in physiological quality of them and it can be transmitted by these. For cultivar Wisconsin, the tests of germination, cold and seedling growth were sensible to the lot stratification in two physiological levels. In the emergence of plants the speed emergence index, the root length and dry matter were able to classify the lots in three physiological categories. For the cultivar Caipira, the tests of germination and cold stratified the lots in two levels of vigor. In the test of growth of seedlings, the length of hypocotyls and root presented sensitivity to the classification of the lots in three physiological levels. For the plant emergence, the length of the hypocotyls and root and, dry matter showed themselves apt to the lot classification according to the physiological quality of them.
O pepino (Cucumis sativus L.) é uma hortaliça pertencente a família Cucurbitaceae, de grande importância no Brasil. É cultivado, preferencialmente, em clima tropical, em condições de temperatura elevada. Possui alto valor econômico, alimentar e social, pois gera empregos diretos e indiretos, exigindo uma demanda de mão-de-obra, desde seu cultivo até sua comercialização. Devido à expressão de cultivo, a qualidade fisiológica e sanitária das sementes constitui um fator importante, sendo responsáveis por limitações na qualidade do produto destinado à comercialização. Assim, objetivou-se com este trabalho verificar a influência de Fusarium moniforme sobre a qualidade fisiológica de sementes de duas cultivares de pepino: Wisconsin e Caipira, através da técnica de inoculação da restrição hídrica, além de avaliar a eficiência de testes de vigor para a estratificação dos lotes conforme a sua qualidade fisiológica. O isolado de F. moniliforme foi obtido de sementes de pepino. Cada cultivar foi dividida em três lotes de diferentes qualidades fisiológicas, diferenciadas pelo envelhecimento artificial. Os tratamentos consistiram em: Testemunha absoluta; BDA + manitol 0,8Mpa; BDA puro; BDA + manitol 0,8Mpa + F. moniliforme; e BDA + F. moniliforme. A qualidade fisiológica das sementes foi avaliada através de testes realizados em condições de laboratório e em casa de vegetação. A restrição hídrica foi eficiente para infectar as sementes das duas cultivares pelo patógeno, comprovando que este influencia negativamente na qualidade fisiológica das mesmas e, pode ser transmitido por estas. Para a cultivar Wisconsin, o teste de germinação, de frio e de crescimento de plântulas foram sensíveis para a estratificação dos lotes em dois níveis fisiológicos. Na emergência de plantas, o índice de velocidade de emergência, comprimento de raiz e massa seca foram capazes de classificar os lotes em três categorias fisiológicas. Para a cultivar Caipira, o teste de germinação e de frio estratificaram os lotes em dois níveis de vigor. No teste de crescimento de plântulas, o comprimento de hipocótilo e de raiz apresentaram sensibilidade para a classificação dos lotes em três níveis fisiológicos. Para a emergência de plantas, o comprimento de hipocótilo e de raiz e, massa seca mostraram-se aptos para a classificação dos lotes de acordo com a qualidade fisiológica dos mesmos.

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Melhores condições de higiene, diminuição na incidência de doenças do solo e alternativa para a falta de espaço são as principais vantagens que o produtor encontra na utilização de recipientes para o cultivo de hortaliças em estufas. Esse trabalho teve como objetivo avaliar diferentes tipos de recipientes e densidade de planta com substrato de fibra de coco para o cultivo de pepino Hokuho, com uso da fertirrigação sob ambiente protegido. O experimento foi conduzido de setembro a novembro de 2006 na área experimental da Fazenda de Ensino, Pesquisa e Extensão da Faculdade de Engenharia – UNESP, Campus de Ilha Solteira – SP. Os tratamentos constaram de cinco recipientes (calha por capilaridade, calha por gotejamento, vaso pequeno, vaso grande e travesseiro) e duas densidades de plantio (uma e duas plantas por cova). O delineamento experimental adotado foi o de blocos ao acaso com 4 repetições, cinco tipos de recipientes e duas densidades de plantio. Avaliou-se Condutividade elétrica (CE), altura das plantas, diâmetro do caule, número de hastes, massa média do fruto, produção de frutos tortos e produção de frutos comerciais. Os recipientes travesseiro, vaso grande e vaso pequeno foram os que proporcionaram as maiores produtividades, sendo recomendados entre eles aquele que propiciar o melhor custo benefício. Em relação à densidade, recomenda-se uma planta por cova, pois esta proporcionou melhores resultados para altura, diâmetro, números de hastes secundárias produzidas, massa média do fruto e com produtividade semelhante a duas plantas por cova.
Better hygiene conditions, decrease in the incidence of diseases of the soil and alternative for the space lack is the main advantages that the producer finds in the use of containers for the cultivation of vegetables in greenhouses. That work had as objective to evaluate different types of containers with coconut fiber substratum for the cucumber crop cultivar Hokuho, with use of the fertirrigation under protected conditions. The study was conducted from September to November of 2006 in the experimental area of São Paulo State University – UNESP, Campus of Ilha Solteira – SP. The treatments consisted of five containers (drain for capillarity, drain for drip, small and big vase and pillow) and two planting densities (one and two plants by hole). It was used a randomized blocks design with 4 repetitions: five types of containers and two planting densities. Electric conductivity was evaluated (CE), height of plants, medium mass of fruit, production of crooked fruits and production of commercial fruits. The containers pillow, large or small vase were those that provided the greatest productivity, and recommended including one that provide the best cost benefit. Regarding density, it is recommended a plant by hole, as this provided better results for height of plants, medium mass of fruit and productivity similar to two plants by hole.

The Genebank of the Institute for the Conservation and Improvement of the Agrodiversity (COMAV) has in its collection 198 accessions of cucumber (Cucumis sativus L.) of Spanish origin, taking charge of preserving and providing their seeds. All the accessions were registered as traditional varieties or landraces, thus the collection of the COMAV represents 5% of the cucumber traditional varieties included in GENESYS. The purpose of the germplasm collections is the preservation of the genetic diversity to make it available for breeders, researchers and other users. Rationalization, that is, reduction of the size collection, is an alternative to cut costs of maintenance. With rationalization the efficiency in management and use of the collection increases; as a consequence, a correct preservation is guaranteed and at least part of the plant materials are available to users. This thesis is included in a project with the objective of the rationalization of the cucumber Spanish collection of the COMAV's Genebank. To achieve this objective, a morphological characterization of the cucumber collection, using fruit and plant descriptors, was carried out. Subsequently, a subset of the accessions were selected to be analyzed with molecular markers, concretely with SSRs (Simple sequence repeats). The morphological characterization was carried out for 206 cucumber accessions, 195 from Spain (178 held at the COMAV, 17 provided by the 'Vegetable Genebank of Zaragoza', BGHZ). Five plants per accession were characterized, with 17 qualitative and 9 quantitative descriptors, eight of them referred to plant traits and 18 related to the fruit. Fruit descriptors were evaluated in at least 25 fruits per accession. The accessions were classified in five groups: 'White', 'Short', 'French', 'Long' and 'Very long'. Principal component analysis showed that, with few exceptions, the accessions were grouped according to their phenotypic similarity. Variability found within each of the groups displayed the potential of these plant materials in breeding programmes for different traits. Maintenance of this collection is of great interest, since variability held by these accessions is not conserved in other European collections, and constitutes a source of genes for cucumber breeding. A representative subset of the accessions evaluated by morphological traits was selected for the molecular characterization. Concretely, molecular diversity of 131 Spanish accessions was evaluated with 23 SSRs. Eighteen of these SSRs were polymorphic; the mean number of alleles, mean observed heterozygosity and mean polymorphic information content were 3.2, 0.065 and 0.229, respectively. Around 60% of the alleles showed a frequency higher than 0.05, and only one allele in the SSR31399 showed a frequency lower than 0.01. In addition, three accession-specific alleles were found. A cluster analysis did not show any relation with morphological types or geographical area. Therefore, these results demonstrated that molecular diversity of the cucumber did not resemble its phenotypic variability. Finally, this study provides information for the rationalization of germplasm. Results from both studies allowed the rationalization of the cucumber Spanish collection of the COMAV. Selection of the accessions was carried out with a combined strategy, considering phenotypic traits, origin and molecular data. The selection included 47 accessions, six of the 'French' type, 15 of the 'Long' type and 24 of the 'Short' type. Moreover, the unique accessions molecularly analyzed belonging to 'Very long' and 'White' types were also selected. The analysis of the set of selected accessions confirmed that it conserved the morphological and molecular variability found in the complete collection.
El Banco de Germoplasma del Instituto de Conservación y Mejora de la Agrodiversidad Valenciana (COMAV) mantiene en su colección 198 entradas de variedades tradicionales de pepino (Cucumis sativus L.) de origen español, haciéndose cargo de la conservación y cesión de sus semillas. La colección de pepino del COMAV representa el 5% de las variedades tradicionales de pepino que figuran en GENESYS. El objeto de las colecciones de germoplasma es conservar la diversidad genética y permitir el acceso a esta a mejoradores, investigadores y otros usuarios. Como alternativa para reducir los costes de mantenimiento se plantea su racionalización, es decir, la reducción del tamaño. De esta forma, se incrementa la eficiencia en el manejo y uso de las mismas, se garantiza una correcta conservación y al menos parte de los materiales se hacen accesibles a los usuarios. Esta tesis se enmarca en un proyecto cuyo objetivo es la racionalización de la colección de pepino español del Banco de Germoplasma del COMAV. Para ello se planteó en primer lugar una caracterización por caracteres de planta y fruto de la colección de entradas de pepino español, para a continuación seleccionar un subconjunto de las mismas para su análisis con marcadores moleculares de tipo microsatélite (Simple sequence repeats, SSR). La caracterización morfológica se llevó a cabo empleando 206 entradas de pepino, 195 de ellas de origen español (178 mantenidas en el COMAV y 17 proporcionadas por el Banco de Germoplasma de Hortícolas de Zaragoza, BGHZ). Se caracterizaron 5 plantas por entrada, empleando 17 descriptores cualitativos y nueve cuantitativos, ocho de ellos de planta y 18 de fruto. Los caracteres de fruto se evaluaron en al menos 25 frutos por entrada. Las entradas analizadas se clasificaron en cinco tipos según las características de fruto: "Blanco", "Corto", "Francés", "Largo" y "Muy largo". El análisis de componentes principales permitió comprobar que, con pocas excepciones, las entradas se agrupaban según su similitud fenotípica. En cualquier caso, la variabilidad observada dentro de cada uno de los grupos puso de manifiesto el potencial de los materiales evaluados para la mejora de distintos atributos. El mantenimiento de la colección resulta de especial interés, dado que la variabilidad que contiene no se encuentra conservada en otras colecciones europeas y constituye una fuente de genes de interés para la mejora del pepino. Un subconjunto representativo de las entradas evaluadas por características morfológicas se seleccionó para la caracterización molecular. En concreto, se evaluó la diversidad genética de 131 entradas españolas, empleando 23 marcadores SSRs. Dieciocho de los SSRs fueron polimórficos en la colección: los valores medios para el número de alelos, la heterocigosidad observada y el contenido en información polimórfica fueron de 3,2, 0,065 y 0,229, respectivamente. Aproximadamente el 60% de los alelos mostraron una frecuencia superior a 0,05, mientras que solo uno de los alelos para el marcador SSR31399 mostró una frecuencia inferior a 0,01. Se identificaron tres alelos específicos de entradas. En el análisis de agrupamientos las entradas no se agruparon según el tipo ni según el área geográfica. Estos resultados demostraron que la diversidad molecular de la colección de pepino no refleja la variabilidad fenotípica. Los resultados de ambas caracterizaciones han permitido llevar a cabo la racionalización de la colección de pepino español del COMAV. Para la selección de las entradas se ha llevado a cabo una estrategia combinada, considerando caracteres fenotípicos, origen y datos moleculares. La selección incluyó 47 entradas, seis de tipo "Francés", 15 del tipo "Largo" y 24 del tipo "Corto". Además, se seleccionaron las únicas entradas de tipo "Muy largo" y "Blanco" caracterizadas molecularmente. Se confirmó que el conjunto de entradas seleccionadas conservaban la variabilidad m
El Banc de Germoplasma de l'Institut de Conservació i Millora de l'Agrodiversitat Valenciana (COMAV) manté en la seua col·lecció 198 entrades de varietats de cogombre (Cucumis sativus L.) d'origen espanyol, fent-se càrrec de la conservació i cessió de les seues llavors. La col·lecció del COMAV representa el 5% de les varietats de cogombre que figuren en GENESYS. L'objectiu de les col·leccions de germoplasma és conservar la diversitat genètica i permetre l'accés a aquesta a milloradors, investigadors i altres usuaris. Com a alternativa per a reduir els costos de manteniment, es planteja la seua racionalització, és a dir, la reducció de la grandària. D'aquesta forma, augmenta l'eficiència en el maneig i ús de les mateixes, es garantix una correcta conservació i al menys part dels materials es fan accessibles als usuaris. Aquesta tesi s'emmarca en un projecte que té com a objectiu la racionalització de la col·lecció de cogombre espanyol del Banc de Germoplasma del COMAV. Per a aconseguir aquest objectiu, es va plantejar en primer lloc una caracterització per caràcters de planta i fruit de la col·lecció d'entrades de cogombre espanyol, per a continuació seleccionar un subconjunt de les mateixes per al seu anàlisi mitjançant marcadors moleculars de tipus microsatèl·lit (Simple sequence repeats, SSR). La caracterització morfològica es va dur a terme utilitzant 206 entrades de cogombre, 195 d'elles d'origen espanyol (178 mantingudes al COMAV, 17 proporcionades pel Banc de Germoplasma d'Hortícoles de Saragossa, BGHZ). Es van caracteritzar 5 plantes per entrada, emprant 17 descriptors qualitatius i nou quantitatius, huit d'ells de planta i 18 de fruit. Els caràcters de fruit s'avaluaren en al menys 25 fruits per entrada. Les entrades analitzades es classificaren en cinc tipus segons les característiques de fruit: "Blanc", "Curt", "Francés", "Llarg" i "Molt llarg". L'anàlisi de components principals va permetre comprovar que, amb poques excepcions, les entrades s'agrupaven segons la seua similitud fenotípica. En tot cas, la variabilitat observada dins de cadascun dels grups va posar de manifest el potencial dels materials avaluats per a la millora de diversos atributs. El manteniment de la col·lecció resulta d'especial interés, atés que la variabilitat que conté no es troba conservada en altres col·leccions europees i constitueix una font de gens d'interés per a la millora del cogombre. Un subconjunt representatiu de les entrades avaluades per característiques morfològiques es va seleccionar per a la caracterització molecular. En concret, es va avaluar la diversitat genètica de 131 entrades espanyoles, emprant 23 marcadors SSRs. Díhuit dels SSRs van ser polimòrfics en la col·lecció: els valors mitjans per al nombre d'al·lels, la heterocigositat observada i el contingut en informació polimòrfica van ser 3,2, 0,065 i 0,229, respectivament. Aproximadament el 60% dels al·lels van mostrar una freqüència superior a 0,05, mentre que sols un dels al·lels per al marcador SSR31399 va mostrar una freqüència inferior a 0,01. Es van identificar tres al·lels específics d'entrades. En l'anàlisi d'agrupaments les entrades no s'agruparen segons el tipus ni segons l'àrea geogràfica. Aquests resultats demostraren que la diversitat molecular de la col·lecció de cogombre no reflectix la variabilitat fenotípica. Els resultats d'ambdues caracteritzacions han permés dur a terme la racionalització de la col·lecció de cogombre espanyol del COMAV. Per a la sel·lecció de les entrades s'ha emprat una estratègia combinada, considerant caràcters fenotípics, d'origen i dades moleculars. La selecció va incloure 47 entrades, sis de tipus "Francés", 15 del tipus "Llarg" i 24 del tipus "Curt". A més, es van seleccionar les úniques entrades del tipus "Molt llarg" i "Blanc" caracteritzades molecularment. Es va confirmar que el conjunt d'entrades seleccionades conservaven la variabilitat
Valcárcel Germes, JV. (2017). Racionalización de la colección de pepino (Cucumis sativus L.) del banco de germoplasma del COMAV [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/86216
TESIS

La aplicación de extractos de algas verdes, pardas y rojas como acondicionador del suelo o fertilizante foliar ha mostrado amplia variedad de respuestas beneficiosas en el crecimiento y rendimiento de plantas cultivadas. En el mundo, se han realizado numerosos bioensayos para cuantificar la bioactividad de extractos, lo cual ha permitido la elaboración a nivel industrial de fertilizantes para la agricultura. En el presente estudio, se evaluó la bioactividad de extractos acuosos de Ulva nematoidea, Macrocystis pyrifera, Lessonia trabeculata y Chondracanthus chamissoi sobre cotiledones etiolados de Cucumis sativus. Los extractos se obtuvieron de 1 g de alga seca en 20 ml de agua destilada a 121 °C, 15 lbs y 30 min (Rama-Rao 1990). Para los ensayos se prepararon diluciones de 10, 5, 2.5 y 1.25%. Para la determinación de la bioactividad tipo auxina-enraizamiento y citoquinina-incremento de biomasa, se utilizó el método del disco de papel. La bioactividad tipo citoquinina-síntesis de clorofila fue determinada utilizando el método de Fletcher y Mccullagh (1971). Los resultados obtenidos muestran que el extracto de M. pyrifera (10%), tuvo un efecto óptimo de bioactividad tipo auxina-enraizamiento de 4.1 ± 0.4 raíces y de bioactividad tipo citoquinina-incremento de biomasa de 22.7 ± 0.8 mg. Respecto de la bioactividad tipo citoquinina-síntesis de clorofila, no se observó un incremento significativo de la síntesis de clorofila. Del presente trabajo de investigación se concluye que los extractos acuosos de Ulva nematoidea, Macrocystis pyrifera y Lessonia trabeculata tienen bioactividad tipo auxina-enraizamiento y citoquinina-incremento de biomasa.
Tesis

Orientador: Shizuo Seno
Banca: Francisco Maximino Fernandes
Banca: Roberto Lyra Villas Boas
Resumo: Melhores condições de higiene, diminuição na incidência de doenças do solo e alternativa para a falta de espaço são as principais vantagens que o produtor encontra na utilização de recipientes para o cultivo de hortaliças em estufas. Esse trabalho teve como objetivo avaliar diferentes tipos de recipientes e densidade de planta com substrato de fibra de coco para o cultivo de pepino Hokuho, com uso da fertirrigação sob ambiente protegido. O experimento foi conduzido de setembro a novembro de 2006 na área experimental da Fazenda de Ensino, Pesquisa e Extensão da Faculdade de Engenharia - UNESP, Campus de Ilha Solteira - SP. Os tratamentos constaram de cinco recipientes (calha por capilaridade, calha por gotejamento, vaso pequeno, vaso grande e travesseiro) e duas densidades de plantio (uma e duas plantas por cova). O delineamento experimental adotado foi o de blocos ao acaso com 4 repetições, cinco tipos de recipientes e duas densidades de plantio. Avaliou-se Condutividade elétrica (CE), altura das plantas, diâmetro do caule, número de hastes, massa média do fruto, produção de frutos tortos e produção de frutos comerciais. Os recipientes travesseiro, vaso grande e vaso pequeno foram os que proporcionaram as maiores produtividades, sendo recomendados entre eles aquele que propiciar o melhor custo benefício. Em relação à densidade, recomenda-se uma planta por cova, pois esta proporcionou melhores resultados para altura, diâmetro, números de hastes secundárias produzidas, massa média do fruto e com produtividade semelhante a duas plantas por cova.
Abstract: Better hygiene conditions, decrease in the incidence of diseases of the soil and alternative for the space lack is the main advantages that the producer finds in the use of containers for the cultivation of vegetables in greenhouses. That work had as objective to evaluate different types of containers with coconut fiber substratum for the cucumber crop cultivar Hokuho, with use of the fertirrigation under protected conditions. The study was conducted from September to November of 2006 in the experimental area of São Paulo State University - UNESP, Campus of Ilha Solteira - SP. The treatments consisted of five containers (drain for capillarity, drain for drip, small and big vase and pillow) and two planting densities (one and two plants by hole). It was used a randomized blocks design with 4 repetitions: five types of containers and two planting densities. Electric conductivity was evaluated (CE), height of plants, medium mass of fruit, production of crooked fruits and production of commercial fruits. The containers pillow, large or small vase were those that provided the greatest productivity, and recommended including one that provide the best cost benefit. Regarding density, it is recommended a plant by hole, as this provided better results for height of plants, medium mass of fruit and productivity similar to two plants by hole.
Mestre

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior
Conselho Nacional de Desenvolvimento Científico e Tecnológico
Frutas e vegetais frescos podem conter vários microrganismos que causam deterioração e problemas quanto à segurança alimentar. Apesar da maioria das evidências mostrarem que a população microbiana está localizada próxima da superfície do fruto, existem relatos sobre localização interna. Métodos eficazes para a inativação desses organismos exigirão informações sobre sua localização. Desenvolveu-se um modelo computacional para determinar a redução microbiana em pepinos frescos submetidos a um processo de branqueamento. O modelo combina equações de transferência de calor transiente em duas dimensões e de cinética de morte microbiana. O tempo de morte térmica (Ftz) para qualquer localização dentro do pepino foi calculado pelo modelo e usado para predizer o tempo necessário para a redução em 2-log da carga microbiana, durante o branqueamento em água quente. Pepinos com diâmetro entre 45 e 55 mm foram branqueados a 60, 80 e 90 oC por 112, 12 e 7 segundos, respectivamente. Os pepinos branqueados foram homogeneizados e amostras foram retiradas para determinação do número da microbiota de aeróbios mesófilos e esporos aeróbios mesófilos. Os resultados experimentais da contagem de aeróbios mesófilos e os resultados preditos pelo modelo computacional foram comparados, demonstrando não existir diferença estatística significativa (P > 0,05) entre os valores encontrados para redução microbiana (em log) na faixa de temperatura empregada. A variação do tempo de morte térmica (Ftz) com a posição obtida a partir do modelo mostrou que os microrganismos estudados estão localizados numa faixa de 0,65mm de espessura a partir da superfície do fruto. A profundidade da distribuição microbiana foi baseada em resultados simulados para alcançar, durante o branqueamento de pepinos, uma redução microbiana de 99,0 e 99,9% (2 e 3 ciclos log) nas temperaturas especificadas. O modelo de transferência de calor e cinética de morte microbiana (TCCMM) deverá ser útil na determinação de processos térmicos mínimos para inativação da microbiota em pepinos, sem perda de características de qualidade. De acordo com a Food and Drug Administration (FDA) tem sido recomendada a redução em 5-log de microrganismos patógenos para alguns grupos de alimentos. Os tempos simulados pelo modelo TCCMM, para que essa redução fosse atingida foram de 186, 18 e 9 segundos a 60, 80 e 90 oC, respectivamente. Entretanto, devido à limitação do número inicial de microrganismos no pepino e presença de organismos resistentes ao calor, não foi possível alcançar experimentalmente, a redução em 5-log da carga microbiana.
Fresh fruits and vegetables may contain numerous microorganisms that relate to spoilage and food safety concerns. Although most evidence indicates that the microbial population is located near the fruit surface, there have been reports of internal location. Effective methods for inactivation of these organisms will require information about their location. A model has been developed to determine the microbial distribution in fresh cucumbers during the blanching process. The model combines two dimensional transient heat transfer and microbial inactivation kinetics equations. Thermal death time (Ftz) at any location within the cucumber was calculated from the model and used to predict microbial reduction of 2-log when cucumbers were blanched in hot water. Cucumbers (between 45 to 55mm diameter) were blanched at temperatures of 60o, 80o and 90oC for 112, 12 and 7 seconds respectively. Blanched cucumbers were homogenized and plated to determine cell counts for total aerobic microflora and aerobic spores. Experimental results for total aerobes and those predicted from the model were compared, which showed no significant statistical difference (P ≥ 0.05) between the reduction values for the blanching temperatures used. Blanching did not reduce the number of microbial spores, as expected. Variation in thermal death time (Ftz) with location as obtained from the model showed that total aerobic microorganisms were located within 0.65mm of the fruit surface. Microbial load depth was based on simulation results for cucumbers blanched to achieve 2 and 3 log reductions at specified temperatures. The Heat Transfer-Microbial Kinetic (HTMK) model should be useful in determining minimal thermal process for inactivation of cucumber microflora without loosing quality factors. According with Food and Drug Administration (FDA), the 5-log reductions have been recommended recently for selected commodities. The times simulated by the HTMK model for attaining this microbial reduction were 186, 18 and 9 seconds at 60, 80 and 90 oC, respectively. However, the 5-log reduction could not be attained experimentally due to limiting initial number of microorganism on/in cucumbers and the presence of heat resistant spores.
Não foram localizados o cpf e o currículo lattes do autor.

A indução de resistência em plantas contra fitopatógenos é um método alternativo de controle de doenças, o qual envolve a ativação de mecanismos de resistência latentes da planta. Hoje no mercado existem poucos produtos que atuam segundo este princípio. Na busca de novas moléculas que possam ser utilizadas em campo, diversos compostos de origem microbiana, com capacidade de estimular uma ou mais respostas de defesa, já foram isolados e caracterizados. A Saccharomyces cerevisiae é uma levedura capaz de induzir resistência e elicitar respostas de defesa em algumas plantas. Com o objetivo de extrair da levedura um ou mais compostos capazes de induzir o acúmulo de fitoalexinas em cotilédones de soja e na proteção dessa leguminosa contra Microsphaera diffusa (agente causal do oídio da soja) e de pepino contra Colletotrichum lagenarium (agente causal da antracnose do pepino), células em suspensão foram autoclavadas. Os compostos assim extraídos foram inicialmente separados através de precipitação etanólica. Em seguida, foram realizadas cromatografias de troca iônica e de afinidade para separar as frações com maior poder elicitor das de baixo poder elicitor. A fração não adsorvida à resina DEAE-Celulose foi a que induziu maior acúmulo de fitoalexinas. No entanto, nenhum dos preparados testados foi capaz de conferir proteção a plantas de soja contra M. diffusa. Já no caso de pepino, plântulas tratadas com as frações resultantes da cromatografia de afinidade apresentaram reduções entre 50 e 70 % de área lesionada causada por C. lagenarium e aumento na atividade de peroxidases. Extratos incorporados à meio de cultivo não apresentaram efeito inibitório sobre o crescimento e esporulação de C. lagenarium. Com base nesses resultados, concluímos que existe na parede da levedura compostos capazes de induzir resistência local em pepino contra C. lagenarium, sendo que pelo menos um destes compostos é um carboidrato, contendo provavelmente manana e glucosamina.
The acquired resistance of plants to pathogens is an alternative method to control diseases which includes the activation of resistance mechanisms in the plants. A few products already commercially available have their action based upon this mechanism. In the search for novel molecules that can be used under field conditions, many compounds from microbes with the ability to stimulate one or more defense responses were already isolated and characterized. Saccharomyces cerevisiae is an yeast with the ability to induce defense responses and resistance in some plants. A suspension of cells from the yeast was autoclaved with the purpose of extracting one or more compounds with the ability to induce the accumulation of phytoalexins in soybean cotyledons and to protect soybean plants against Microsphaera diffusa (causal agent of powdery mildew) and plants of cucumber against Colletotrichum lagenarium (causal agent of anthracnose). The compounds extracted by this method were separated using ethanolic precipitation. After this step, the fractions of higher elicitation activity were separated from those of lower one by using ion exchange cromatography and affinity cromatography. The non-adsorbed fraction to DEAE-Cellulose was the one that induced the highest accumulation of phytoalexins. However, none of the fractions were able to protect soybean plants from M. diffusa. In the case of cucumber, seedlings treated with the fractions from affinity chromatography were able to reduce disease symptoms caused by C. lagenarium by 50 to 70 % and to increase the activity of peroxidases. Extracts that were incorporated into growing media did exhibit any inhibitory effect on in vitro growth and sporulation of C. lagenarium. According to these results, it is possible to conclude that there are compounds in the cell walls of the yeast that are able to induce local resistance to C. lagenarium in cucumber and that at least one of these compounds is a carbohydrate that likely contains mannan and glucosamine.

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Fundação de Amparo à Pesquisa do Estado do Amazonas
The search for alternative methods for plant disease control has been the target of several researches aiming to reduce the use of pesticides. Accordingly, this research evaluated the effect of chemical resistance inductors in the control of the corinespora s leaf spot [Corynespora cassiicola (Berk. end Curt.) Wei] in cucumber plants in a green house. Initially, an experiment was established to evaluate the effect in vitro of the inductors in the development of C. cassiicola. The products studied were the following Bion® in dose of 0.050 and 0.025g/500, Ecolife® in dose of 1.0 and 2.5 mL/500 and Fertisil® in dose of 0.025 and 0.05g/500 incorporated the BDA culture medium. The experiment was was randomly delineated with ten repetitions. The evaluations were achieved by measuring the colony diameters and evaluating the spore s production by the counting method in drop. The following commercial genotypes of cucumber plants were evaluated regarding the resistance and susceptibility to the aforementioned disease: Aodai, General Lee F1, Hokushim, Hybrid Japanese F1 (Soudai), Joia, Marketmore 76 (long green), Natsubayashi, Natsu suzumi, Sprint 440 II and Tsuyataro. The plants were inoculated at an age of 30 days with an inoculum s suspension in the concentration of 104 conidia/mL of the pathogen..The evaluation of the disease severity was made in agreement with the scale of gradings described by Oliveira et al. (2006). The genotypes Tsuyataro and Aodai were selected as susceptible and disease resistance, respectively, and used in the experiments with the resistance inductors. The inductors were tested in a green house, using plants of the Tsuyataro and Aodai genotypes, in random delineation with five repetitions. Doses in the range of 0.025, 0.050, 0.075 and 0.15g of Bion®/500mL; 1.0, 2.5, 3.0 and 7.5 mL of Ecolife®/500mL; 4.0, 7.5, 12.0 and 22.5g of Fertisil®/500mL were tested in cucumber plants. These products were applied 48 hours before inoculation with the pathogen. The severity, number and lesion size and the fungal incubation period were evaluated for each treatment. The data was statistically analyzed and the average compared by the Tukey s test (5%) using the SAEG statistic program. In the in vitro assays, the fungus was highly sensible to Fertisil® for the dosage used, causing a fungitoxic effect. The treatments with Bion® and Ecolife® had no effect upon mycelial growth and the fungal spore production. The application of inductors in a green house was not efficient to control the disease in the tested dose.
A busca por métodos alternativos para o controle de doenças de plantas tem sido alvo de diversas pesquisas, visando reduzir o uso de agrotóxicos. Neste sentido buscou-se avaliar o efeito de indutores químicos de resistência no controle da mancha de corinéspora [Corynespora cassiicola (Berk. e Curt.) Wei] em pepineiro. Inicialmente foi avaliado o efeito dos indutores in vitro sobre o desenvolvimento de C. cassiicola. Foram estudas os produtos Bion® nas doses de 0,050 e 0,025g/500, Ecolife® nas doses de 1,0 e 2,5mL/500 e Fertisil® nas doses de 0,025 e 0,050g/500 incorporado no meio de cultura BDA. O delineamento experimental foi ao acaso com dez repetições. As avaliações foram realizadas através de medição do diâmetro das colônias e a produção de esporos foi avaliada pelo método de contagem em gota. Os genótipos comerciais de pepineiro Aodai, General Lee F1, Hokushim, Japonês Híbrido F1 (Soudai), Jóia, Marketmore 76 (verde comprido), Natsubayashi, Natsu suzumi, Sprint 440 II e Tsuyataro foram avaliados quanto à resistência e suscetibilidade à doença. As plantas foram inoculadas aos 30 dias de idade com uma suspensão de esporos na concentração de 104 conídios/mL do patógeno. A avaliação da severidade da doença foi feita de acordo com escala de notas descrita por Oliveira et al. (2006). Foram selecionados os genótipos Tsuyataro, como suscetível e Aodai, como resistente à doença, para serem usados nos experimentos com os indutores de resistência. Os indutores foram testados em casa de vegetação, utilizando plantas dos genótipos Tsuyataro e Aodai, em delineamento ao acaso com cinco repetições. Os tratamentos constituíram nas doses de 0,025, 0,050, 0,075 e 0,15g de Bion®/500mL; 1,0, 2,5, 3,0 e 7,5mL de Ecolife®/500mL; 4,0, 7,5, 12,0 e 22,5g de Fertisil®/500mL aplicados 48 horas antes da inoculação com o patógeno. Foi avaliado a severidade, número e tamanho de lesões e período de incubação do fungo em cada tratamento. Os dados foram analisados estatisticamente e as médias dos tratamentos comparadas pelo teste Tukey (5%) utilizando o programa estatístico SAEG. Nos ensaios in vitro o fungo foi sensível ao Fertisil® nas dosagens utilizadas causando em efeito fungitóxico. Nos tratamentos com Bion® e Ecolife® não houve efeito sobre o crescimento micelial e a produção de esporos do fungo. A aplicação dos indutores em casa de vegetação não foi eficiente para controlar a doença nas doses testadas.

L’accessió exòtica de meló PI 161375 cultivar Songwhan Charmi (SC) presenta resistència a la major part de soques de Cucumber mosaic virus (CMV). S’ha descrit que la resistència a soques del subgrup II de CMV és recessiva i que està controlada pel gen cmv1, que és capaç d’evitar l’entrada del virus al floema mitjançant una restricció a nivell de les cèl·lules de la beina. Aquesta restricció depèn de la proteïna de moviment (MP) viral, que és el determinant de la virulència. Per tenir resistència a la soca CMV-M6, pertanyent al subgrup I, a part de cmv1, també es requereixen dos altres QTLs: cmvqw3.1 i cmvqw10.1. No obstant, una soca més agressiva del subgrup I, CMV-FNY, és capaç de superar la resistència conferida per cmv1/cmvqw3.1/cmvqw10.1. Aquesta tesis té com objectius (i) identificar altres QTLs responsables de la resistència a CMV-FNY, (ii) caracteritzar la resistència conferida pels QTLs cmv1/cmvqw3.1/cmvqw10.1, i (iii) identificar els factors de virulència implicats en aquests tres QTLs. L’anàlisi de QTLs es va dur a terme mitjançant diverses poblacions F2 obtingudes del creuament entre les línies resistents a CMV-FNY, DHL142 i DHL69, i línies susceptibles. Es van detectar alguns possibles QTLs d’efecte menor als LG II, LG IX, LG X i LG XII. No obstant, cap d’aquests QTLs va ser reproduïble a les diferents poblacions avaluades, ni pels diferents mètodes de fenotipat utilitzats. Un cop avaluat el sistema d’anàlisi de QTLs emprat es va demostrar que aquest no havia estat l’apropiat per QTLs d’efecte menor. Probablement el factor limitant hauria estat la robustesa de l’avaluació fenotípica de la infecció en poblacions F2. L’estudi de la resistència, conferida per combinacions de dos o tres QTLs, va mostrar que malgrat les plantes s’acabaven infectant per CMV-FNY, hi havia un retard en la infecció, indicant que la resistència intervé restringint el moviment viral. Més endavant es va demostrar que la restricció actua a nivell de l’entrada al floema, enlloc d’intervenir a nivell del moviment del virus un cop dins del floema. Així doncs, cmvqw3.1 i cmvqw10.1 actuen dificultant el moviment de CMV-FNY al mateix punt de la infecció viral on ho fa cmv1 amb CMV-LS. La generació de pseudorecombinants entre CMV-FNY / CMV-M6 i CMV-FNY / CMV-LS va demostrar que el determinant de la virulència no es troba al RNA3. Aquests resultats suggereixen que la resistència a CMV de l’accessió SC es construeix mitjançant diferents nivells, essent cmv1 el primer nivell conferint resistència envers el subgrup II; el segon nivell cmvqw3.1 i cmvqw10.1 conferint una resistència eficient envers CMV-M6; i un tercer nivell on altres QTLs encara per determinar serien necessaris per conferir una resistència eficient a CMV-FNY. Actualment, sabem que els dos primers nivells de resistència estarien actuant restringint l’entrada de CMV al floema
La accesión de melón exótico PI 161375, cultivar Songwhan Charmi (SC) es resistente a la mayoría de las cepas de Cucumber mosaic virus (CMV). La resistencia a las cepas del subgrupo II de CMV es recesiva y controlada por el gen cmv1, que es capaz de prevenir la entrada del virus en el floema deteniéndolo en las células de la vaina que rodean la vena. Esta restricción depende de la proteína de movimiento (MP), el determinante de la virulencia frente a este gen. Para resistir a la cepa CMV-M6, del subgrupo I, se requieren dos QTL más, cmvqw3.1 y cmvqw10.1, funcionando en colaboración con cmv1. Sin embargo, CMV-FNY, una cepa más agresiva del subgrupo I, es capaz de superar la resistencia conferida por cmv1/cmvqw3.1/cmvqw10.1. En esta tesis, nuestro objetivo es (i) identificar los QTL adicionales responsables de la resistencia a CMV-FNY, (ii) caracterizar la resistencia conferida por los QTL cmv1/cmvqw3.1/cmvqw10.1 e (iii) identificar los factores de virulencia involucrados con estos QTL. El análisis de QTL se abordó desarrollando varias poblaciones F2 entre las líneas DHL142 o DHL69, resistentes a CMV-FNY, y varias líneas de melón susceptibles a CMV-FNY, donde se detectaron varios QTL menores en LG II, LG IX, LG X y LG XII. Sin embargo, ninguno de estos QTLs fue detectado reproduciblemente en varias poblaciones F2, ni utilizando diferentes métodos de fenotipado, lo que indicó que nuestro sistema de detección de QTL no es apropiado para detectar QTLs menores. El factor limitante más probable puede ser la dificultad del fenotipado de la infección para la detección de QTLs en una población F2. El estudio de la resistencia conferida por combinaciones de dos o los tres QTL mostró que, aunque las plantas eran susceptibles a CMV-FNY, hubo un retraso en la infección, lo que indica que la resistencia implica una restricción del movimiento viral. Un análisis posterior mostró que la restricción funcionaba al nivel de la entrada al floema, más que al nivel del movimiento dentro del floema. Por lo tanto, esto indica que cmvqw3.1 y cmvqw10.1 están dificultando el movimiento de CMV-FNY en el mismo paso de la infección viral donde cmv1 restringe CMV-LS. Los pseudorecombinantes generados entre CMV-FNY / CMV-M6 y entre CMV-FNY / CMV-LS demostraron que el determinante de virulencia no mapeaba en el RNA3. Tomados en conjunto, nuestros resultados sugieren que la resistencia al CMV en la accesión SC está formada por una serie de niveles de resistencia, siendo cmv1 el primer nivel, efectivo contra las cepas del subgrupo II; el segundo nivel, formado por cmvqw3.1 y cmvqw10.1, que cooperarían con cmv1 para proporcionar resistencia frente a CMV-M6; y el tercer nivel sería el QTL no identificado aún, necesario para la resistencia frente a CMV-FNY. En la actualidad, sabemos que los dos primeros niveles de resistencia estarían participando en la restricción de la entrada de CMV al floema.
The exotic melon accession PI 161375 cultivar Songwhan Charmi (SC) shows resistance to most of Cucumber mosaic virus (CMV) strains. The resistance to CMV subgroup II strains was reported as recessive, controlled by the gene cmv1 which is able to prevent the phloem entry of the virus by restricting it in the bundle sheath cells. This restriction depends on the movement protein (MP), the determinant of virulence. Two more QTLs, cmvqw3.1 and cmvqw10.1 are required, working together with cmv1, for the resistance to the subgroup I strain CMV-M6. However, CMV-FNY, a more aggressive strain from subgroup I, was able to overcome the resistance conferred by cmv1/cmvqw3.1/cmvqw10.1. In this thesis we aim to (i) identify the additional QTLs responsible for the resistance to CMV-FNY, (ii) characterize the resistance conferred by the QTLs cmv1/cmvqw3.1/cmvqw10.1 and (iii) identify the virulence factors involved with these QTLs. QTL analysis was addressed developing several F2 populations made between the CMV-FNY-resistant lines DHL142, DHL69 and several CMV-FNY-susceptible melon lines. Several putative minor QTLs were detected in LG II, LG IX, LG X and LG XII. However, none of these QTLs were reproducibly detected neither in several F2 populations nor using different methods of phenotyping. The evaluation of our QTL detecting system indicated that it is not appropriate for detecting minor QTL, being the most probable limiting factor the correct phenotyping of the infection for QTL detection in a F2 population. The study of the resistance conferred by combinations of two or the three QTLs showed that, although the plants were susceptible to CMV-FNY, there was a delay in the infection, indicating that the resistance involves a restriction of the viral movement. Further analysis showed that the restriction worked at the level of phloem entry, rather than at the level of movement within the phloem. Therefore, this indicates that cmvqw3.1 and cmvqw10.1 are impairing CMV-FNY movement at the same step of the viral infection where cmv1 restricts CMV-LS. Pseudorecombinants generated between CMV-FNY / CMV-M6 and between CMV-FNY / CMV-LS demonstrated that the determinant of virulence was not mapped in RNA3. Taken together, our results suggest that the resistance to CMV in SC accession is built by a series of resistance layers, being cmv1 the first layer, against subgroup II strains; the second layer, cmvqw3.1 and cmvqw10.1, that provide efficient resistance to CMV-M6; and the third layer being the unknown QTL, necessary for efficient resistance to CMV-FNY. At present, we know that the first two layers of resistance would be working in the restriction of CMV entry to the phloem.