Letteratura scientifica selezionata sul tema "Controlled germination"
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Articoli di riviste sul tema "Controlled germination"
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Liu, Yongjie, e Fujiang Hou. "Effects of three-dimensional soil heterogeneity on seed germination in controlled experiments". Journal of Plant Ecology 14, n. 1 (19 ottobre 2020): 1–9. http://dx.doi.org/10.1093/jpe/rtaa070.
Testo completoAbstract (sommario):
Abstract Aims Seed germinations react to their local growing conditions, but the impacts of soil heterogeneity on seed germinations are not well known. Methods Effects of three-dimensional soil heterogeneity on seed germinations of grasses species were explored, where two levels of such soil heterogeneity were created via alternatively filling nutrient-poor and nutrient-rich substrate in pot in all directions. Patch sizes of the two heterogeneity levels are around 7.5 and 15 cm, respectively. Fifty seeds of each of the grasses species (Lolium perenne and Elymus nutans) were set either in these heterogeneous soils or in petri dishes with distilled water. Seed germinations of these species were daily recorded. Important Findings We found that pots with smaller patches had relatively lower germination rate, which is consistent with our expectation that shorter distance between nutrient-rich and nutrient-poor patches in pots with smaller patches allows plants to reduce their germination rates and delay their germination, in order to reduce the negative impacts of the strong variation of soil resources in these pots. Our results also revealed that pots with smaller patches yielded more heterogeneous seed germination, i.e. seed germinations highly diverged among these pots. These findings highlight that the realistic three-dimensional design can improve our understanding of seed germination as driven by soil spatial heterogeneity.
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Vrzalová, Jana, e Pavel Knot. "The effect of seed age and treatment by Proradix method on germinability and initial growth of selected meadow grass (Poa pratensis) varieties". Acta Universitatis Agriculturae et Silviculturae Mendelianae Brunensis 59, n. 5 (2011): 309–14. http://dx.doi.org/10.11118/actaun201159050309.
Testo completoAbstract (sommario):
The goal of the study conducted in 2008 and 2010 at the Research Forage Production Station in Vatín was to investigate the influence of seed age and seed treatment by Proradix method on the germination dynamics, total germinating capacity and initial growth rate of selected meadow grass varieties. The testing was carried out in controlled conditions on the germinator. Our results indicate that the age of seed significantly affects both the germination dynamics and the total germinating capacity. On day 7 after the establishment of the trial, a significantly higher germinating capacity was observed in the 4-year old seed (33.3%) as compared with the 2-year old seed (17.4%). Nevertheless, from day 13, higher germination values were recorded in the younger seed and its total achieved germinating capacity was significantly higher too (+7.2%). Interesting was a finding that the older seed of most varieties showed a more readily oncoming germination, which may play a quite important role in some cases namely in meadow grass, which is known by slow initial growth. The older seed exhibited significantly lower values of both above-ground biomass and the biomass of roots. The Proradix method appeared as efficient in boosting the total germinating capacity. It significantly increased germination rate as well as total germinating capacity. At the same time, a positive effect was observed of treatment by this method on the length of both shoot and root parts; the difference was statistically insignificant though.
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Amaral-Baroli, Adriana, e Massanori Takaki. "Phytochrome controls achene germination in Bidens pilosa L. (Asteraceae) by very low fluence response". Brazilian Archives of Biology and Technology 44, n. 2 (giugno 2001): 121–24. http://dx.doi.org/10.1590/s1516-89132001000200002.
Testo completoAbstract (sommario):
Achene without ornament of the tegument were light insensitive with germination under all tested light conditions. Achene with verrucose ornament of the tegument presented low germination under darkness and high germination under light conditions. By pre-incubation at 36° C for remotion of pre-existing Pfr and by comparison of results of counting of dark germinating achenes at the end of experiment and daily under dim green safe light (0.001mumol m-2 s-1 nm-1) we concluded that germination was controlled by phytochrome through very low fluence response.
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Blumenthal, MJ, SC Aston e CJ Pearson. "Effect of temperature and moisture potential on germination and emergence in Lotus sp". Australian Journal of Agricultural Research 47, n. 7 (1996): 1119. http://dx.doi.org/10.1071/ar9961119.
Testo completoAbstract (sommario):
Two controlled cabinet experiments compared the germination of 6 Lotus genotypes over a range of temperature (0-40�C) and moisture potentials (0 to -1.2 MPa). A field experiment compared the emergence of 5 Lotus genotypes over 18 sowing dates. Lotus cornzculatus cv. Grasslands Goldie. L. uliginosus, Grasslands Maku, G4703, G4704. and cv. Sharnae were included in both the controlled cabinet and field experiments. Lotus suaveolens CPI 35903 was included in the controlled cabinet experiments only and Trifolium repens cv. Haifa was included as a control in the field study. Of the commercially available Lotus cultivars, Grasslands Goldie provides the greatest flexibility in terms of sowing date in coastal New South Wales and could be successfully sown even in late autumn and winter as it had the lowest base temperature for germination and field emergence. G4703, Sharnae, and G4704 had a lower base moisture potential for germination than the other 3 Lotus genotypes but this was not translated to better field emergence. Lotus suaveolens had an extremely low base temperature for germination (l�C) compared with L. uliginosus cv. Grasslands Maku (6.4�C). Hybridisation of this species with both L. corniculatus and L. uliginosus could result in germplasm capable of germinating better at low temperature but still able to maintain the perenniality, rhizomatous habit, and presence of condensed tannin of L. uliginosus.
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Cuena-Lombraña, Alba, Marco Porceddu, Caterina Angela Dettori e Gianluigi Bacchetta. "Gentiana lutea L. subsp. lutea seed germination: natural versus controlled conditions". Botany 94, n. 8 (agosto 2016): 653–59. http://dx.doi.org/10.1139/cjb-2016-0030.
Testo completoAbstract (sommario):
Gentiana lutea L. subsp. lutea is a geophyte that occurs in the central-southern European mountains. We investigated its germination ecophysiology with the main aim of evaluating seed germination behaviour under controlled and natural conditions. Seeds from four natural sites were tested for germination requirements under a range of different temperatures, and by comparing the results with those obtained under both cold stratification at 5 °C and treatment with GA3. We simultaneously carried out germination tests at each collecting site, and soil temperatures were recorded. Our results indicate that germination under controlled conditions is limited by high temperatures (25 °C), below which GA3 has a remarkable effect on germination percentages. Cold stratification did not have an influence on the germination response, thus suggesting that a temperature of 5 °C is not sufficient to break seed dormancy; this result was supported by soil temperatures. Gentiana lutea created a short-term persistent seed bank, and seeds mainly germinated in their first year. The germination under controlled conditions was similar in all accessions, while different responses were found in the field, where a potential influence of the aspect was observed. These findings underscore the importance of understanding germination behaviour in the field to define the real thermal requirements of a taxon.
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Hermesh, R., e S. N. Acharya. "Influence of maternal plant environment and provenance on alpine bluegrass seed germination". Canadian Journal of Plant Science 72, n. 3 (1 luglio 1992): 801–8. http://dx.doi.org/10.4141/cjps92-096.
Testo completoAbstract (sommario):
Adequate restoration of alpine disturbances requires seed material capable of germinating in high proportions and at a rapid rate. Germination of alpine bluegrass (Poa alpina L.) seeds of different provenances and produced under different environmental conditions was compared under uniform conditions of 16/8 h cycles of light/dark and 22/15 °C temperature. Seeds from nursery plots at the Alberta Environmental Centre, Vegreville, germinated in significantly higher proportions and faster than seeds from the same accessions grown in alpine environments. Alpine bluegrass clones grown in controlled environment chambers set at 22/15 °C and 15/8 °C light/dark with a 16-h photoperiod produced seeds with higher rates of germination and greater cumulative germination than seeds produced in an 8/1 °C regime. It is suggested that alpine blue-grass seeds with high germination percentage and rates are best produced under prairie nursery conditions.Key words: Alpine bluegrass, Poa alpina L., seed germination, maternal environment
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Finch-Savage, W. E., e C. I. McQuistan. "Performance of carrot seeds possessing different germination rates within a seed lot". Journal of Agricultural Science 110, n. 1 (febbraio 1988): 93–99. http://dx.doi.org/10.1017/s0021859600079739.
Testo completoAbstract (sommario):
SummaryThe relationship between germination rate within a carrot seed lot and subsequent seedling performance was studied in four seed lots of different viability. Seedling performance was assessed using slope tests conducted under controlled conditions and in the field following fluid drilling under a range of environmental conditions. Germination rate within a seed lot was positively related to vigour measured by slope tests, percentage emergence and seedling weight, and was negatively related to the spread of emergence times (In variance days) and the coefficient of variation (c.v.) of seedling weights. Sowing seeds selected as fast germinating resulted in greater seedling emergence percentages over a range of environmental conditions than when sowing seeds selected as slowly germinating.
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Matthews, S. "Approaches to the indirect evaluation of germination and vigour". Scientia Agricola 55, spe (1998): 62–66. http://dx.doi.org/10.1590/s0103-90161998000500011.
Testo completoAbstract (sommario):
In comparisons of six seed lots of different F1 hybrid cultivars of cauliflower with similarly high laboratory germinations (above 90%) separation in germination was achieved after controlled deterioration (C.D.) at 24% moisture content (m.c.) and 45 0C for 24 hours. This measure of vigour was related to the position of the lots on the seed survival curve and was highly predictive of the longevity of the lots when stored at 15% m.c. and 20 0C for 12 and 16 weeks. When each seed lot was deteriorated at 24% m.c. for increasing times (from 0 to 36 hours) a reduction in the subsequent percentage germination was seen, which, using probit transformed percentages, was significantly and linearly related to the leakage of electrolytes into seed soak water over 24 hours. The case is made for an approach to the indirect evaluation of germination and vigour using C.D. followed by measurements of leakage that could be more discerning and rapid than the present laboratory germination test.
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Marsh, Lurline E., e Mohsen Dkhili. "GERMINATION AND GROWTH OF COWPEA AND PIGEONPEAS AT CONTROLLED LOW TEMPERATURES". HortScience 27, n. 6 (giugno 1992): 682f—682. http://dx.doi.org/10.21273/hortsci.27.6.682f.
Testo completoAbstract (sommario):
Twenty cowpea (Vigna unguiculata) and 10 early maturing pigeonpea (Cajanus cajan) genotypes were grown at 20/10 C, and 17/10 C day/night and 16 hr. photoperiod to assess their germination and growth. At 20/10 C eighteen cowpea genotypes including the line MN13, and the cultivar, Pinkeye Purple Hull commenced germination at 6 days after planting and showed at least 80% germination 21 days later. Generally, genotypes did not differ significantly in germination and seedling growth up to 45 days later. At 17/10 C two of the cowpea genotypes IT 82E-16 and IT 84E-124 attained at least 90% germination within 21 days after planting. Seedling, growth of these genotypes did not differ and plants began to die 70 days after planting. The pigeonpeas at 17/10 C commenced germination at 9-10 days like many of the cowpeas. Most had at least 50% germination and did not differ in shoot elongation and leaf production. All pigeonpeas flowered between 109 and 136 days after planting and produced pods with immature seeds.
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Bauerová, Lucie, Shiferaw Alem Munie, Kateřina Houšková e Hana Habrová. "Germination of Dracaena cinnabari Balf.f. Seeds under Controlled Temperature Conditions". Forests 11, n. 5 (6 maggio 2020): 521. http://dx.doi.org/10.3390/f11050521.
Testo completoAbstract (sommario):
Research highlights: This study is focused on the germination of Dracaena cinnabari seeds in order to discover the possibility of natural and artificial regeneration of this species. Background and Objectives: This study aimed to determine the optimal temperature for D. cinnabari seed germination, e.g., the temperature at which the germination percentage and germination rate (vitality) are the highest. The objectives of this study are to: (1) determine the optimal temperature for the germination of D. cinnabari seeds, (2) compare the suitability of different seed collection methods, and (3) compare the germination parameters of seeds that were collected from different localities. The results of this study will contribute to obtaining the highest number of seedlings from limited seed material for reforestation of the most endangered localities of D. cinnabari species. Materials and methods: Four seed sections were employed. These sections were directly collected from either the fruits of a cut panicle or the ground and were obtained from different localities that differ in altitude. The seeds were tested in a greenhouse while using Petri dishes at three different temperatures—22, 26, and 30 °C—with four replicates of 25 seeds of each section. ANOVA and the t-test were employed for data analysis. Results: The highest germination percentages (GPs) were achieved at 26 °C and 30 °C, which were 84.6% and 82.5%, respectively. The ANOVA and t-test results showed that the germination index (GI) of the species was relatively higher at a temperature of 30 °C relative to that at other temperatures in the study. Although seeds that were collected from the tree achieved a higher GP, the t-test result showed no significant differences in the GI of D. cinnabari seeds that were collected from the ground and from the tree (p > 0.05). Overall, the findings of this study show that temperature has substantial influence on the germination of seeds of D. cinnabari. Therefore, we recommend a temperature of 30 °C to facilitate the germination of D. cinnabari, as it achieved the highest GI at this temperature relative to that at the other temperatures (22 °C, 26 °C) applied in this study.
Tesi sul tema "Controlled germination"
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Kopec, D. M., R. Scott, B. D. Munda, M. J. Pater, C. F. Mancino e A. E. Ralowicz. "Germination of Lehman Lovegrass and Black Grama Under Controlled Environment Conditions". College of Agriculture, University of Arizona (Tucson, AZ), 1989. http://hdl.handle.net/10150/216078.
Testo completoAbstract (sommario):
Mechanical scarification greatly improved the germination of Lehmann Lovegrass seed. Depending on the type and duration of scarification, seed gemzination can be improved from 10 %-12% germination (untreated seed) to over 90% (60-second scarification in a commercial seed scarifier). Black grama is sensitive to both dehulling and dehulling followed by scarification. Unhulled black grama seed should be used for field plantings.
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Zida, Didier. "Impact of forest management regimes on ligneous regeneration in the Sudanian savanna of Burkina Faso /". Umeå : Dept. of Forest Genetics and Plant Physiology, Swedish University of Agricultural Sciences, 2007. http://epsilon.slu.se/200766.pdf.
Testo completo
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Minamiguchi, Joice Yuri. "Prospecção de fungos micorrízicos e promoção de crescimento em orquídeas". Universidade do Oeste Paulista, 2017. http://bdtd.unoeste.br:8080/jspui/handle/jspui/1086.
Testo completoAbstract (sommario):
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Joice Yuri Minamiguchi.pdf: 1305334 bytes, checksum: ce408a4b1cb0c85010e11bc39b0761d9 (MD5)Made available in DSpace on 2018-07-27T17:21:00Z (GMT). No. of bitstreams: 1 Joice Yuri Minamiguchi.pdf: 1305334 bytes, checksum: ce408a4b1cb0c85010e11bc39b0761d9 (MD5) Previous issue date: 2017-12-19
Orchid seeds do not have practically reserve of energy and are not able to absorb what exists, necessitating a symbiosis with mycorrhizal fungi for germination to occur. During the aclorophyll stage of embryo development, these are the dependent on the mycorrhizal association, because fungi provide simple sugars to the plant from digested pelotons. The objective of this work was to isolate mycorrhizal fungi of orchid in cultivated and wild plants, that could promote the germination and development of seedlings of different species. Roots of nine species of orchids were collected for the isolation by peloton, four of natural environment, three from in vitro culture that developed and grew in greenhouse orchid and two who were born spontaneously in the greenhouse orchid. This methodology promoted the isolation of nine anamorphic rhizoctonioid from two species from a natural environment, Prescotia sp and Oeceoclades maculata and of a spontaneous species in greenhouse orchid, Arundina bambusifolia. In pots of three species of orchids, Vanda sp., Cattleya tigrina and Cattleya walkeriana, were placed baiting containing seeds of the same. This methodology obtainedthe isolation of eight anamorphic rhizoctonioid fung from Cattleya tigrina and Cattleya walkeriana. Were made the quantitative and qualitative morphological characterizations of the 17 isolates obtained by the two methodologies, and these characteristics were used for the formation of groups by the grouping method UPGMA. This method together with the morphological characteristics made it possible to classify four genera of mycorrhiza, Epulorhiza, Ceratorhiza, Moniliopsis and Rhizoctonia-like. The isolates were separated into 7 different groups, and one isolate from each group was used for the symbiotic germination of six species of orchids, Cattleya brevicaulis, Cattleya tigrina, Cattleya walkeriana, Cattleya labiata, Dendrobium signatum and Encyclia cordigera. Posteriorly confirmation of the mycorrhizal association was made, of protocorm resulting from symbiotic germination. Ninety days after seeding, seedlings of the six species that germinated were transferred to flasks, and 180 days after seeding were evaluated growth and dry mass variables. The methodology of isolation by peloton promoted the isolation of mycorrhiza from plants of natural environment and from a spontaneous in greenhouse orchid, the baiting methodology was able to promote the isolation of mycorrhiza from plants that were born and developed in a controlled environment. Of the seven inoculum, six were efficient to promote the germination of the six species tested, but only five inoculum presented growth of seedlings. One inoculum is no specific, presenting better results, improving seedling growth in five of the evaluated species.
Sementes de orquídea praticamente não possuem reserva de energia e não são capazes de absorver as que possuem, necessitando de uma simbiose com fungos micorrízicos para que ocorra a germinação. Durante a fase aclorofilada do desenvolvimento do embrião, estes são dependentes da associação micorrízica, pois os fungos fornecem açúcares simples oriundos de pelotons digeridos pela planta. O objetivo deste trabalho foi isolar fungos micorrízicos de orquídeas cultivadas e silvestres, que pudessem promover a germinação e o desenvolvimento de plântulas de diferentes espécies. Raízes de nove espécies de orquídeas foram coletadas para o isolamento por peloton, quatro de ambiente natural, três oriundas de cultivo in vitro aclimatizadas e crescidas em um orquidário e de duas que nasceram espontaneamente no orquidário. Esta metodologia obteve o isolamento de nove fungos rizoctonióides anamorfos de duas espécies oriundas de ambiente natural, Prescotia sp e Oeceoclades maculata e de uma espécie espontânea no orquidário, Arundina bambusifolia. Nos vasos de três espécies Vanda sp., Cattleya tigrina e Cattleya walkeriana, foram colocados pacotes de isca contendo sementes das mesmas. Esta metodologia obteve o isolamento de oito fungos rizoctonióides anamorfos de Cattleya tigrina e Cattleya walkeriana. Foram feitas as caracterizações morfológicas quantitativas e qualitativas dos 17 isolados obtidos pelas duas metodologias, e essas características foram usadas para a formação de grupos pelo método de agrupamento UPGMA. Esse método juntamente com as características morfológicas possibilitou a classificação de quatro gêneros de micorrizas, Epulorhiza, Ceratorhiza, Moniliopsis e Rhizoctonia-like. Os isolados foram separados em sete grupos diferentes, e um isolado de cada grupo foi utilizado para a germinação simbiótica de seis espécies de orquídeas, Cattleya brevicaulis, Cattleya tigrina, Cattleya walkeriana, Cattleya labiata, Dendrobium signatum e Encyclia cordigera. Posteriormente foi feita a confirmação da associação micorrízica, dos protocórmios resultantes da germinação simbiótica. Noventa dias após a semeadura, plântulas das seis espécies que germinaram foram transferidas para frascos, e 180 dias após a semeadura foram avaliadas variáveis de crescimento e de massa seca. A metodologia de isolamento por peloton promoveu o isolamento de micorrizas de plantas de ambiente natural e de uma espontânea em orquidário. A metodologia por isca foi capaz de promover o isolamento de micorrizas de plantas que nasceram e se desenvolveram em ambiente controlado. Dos sete inóculos, seis foram eficientes para promover a germinação de sementes das seis espécies testadas, mas somente cinco inóculos exibiram crescimento de plântulas. Um inóculo demonstrou ser não específico, apresentando melhor resultado melhorando o crescimento de plântulas em cinco das espécies avaliadas.
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Arc, Erwann. "Étude de l'implication des oxides d'azote dans le controle de la dormance des graines d'Arabidopsis thaliana". Thesis, Paris, AgroParisTech, 2013. http://www.theses.fr/2013AGPT0011.
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Oliveira, André Pereira. "Controle de alternaria em sementes de cenoura: tratamentos alternativos". Universidade Federal de Pelotas, 2015. http://repositorio.ufpel.edu.br:8080/handle/prefix/3313.
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A perspectiva futura do agronegócio de hortaliças no mundo é oportuna, pela participação crescente do mercado internacional e expansão de oportunidade no mercado interno. Dentro deste contexto, têm ocorrido problemas associados à germinação das sementes de cenoura, em decorrência de contaminação por fungos. Por isso, a hipótese do trabalho é a de que sementes de cenoura podem ser influenciadas no processo germinativo por apresentarem contaminação por fungos e se desinfestadas superficialmente com diferentes tratamentos, estas podem promover um melhor desempenho na germinação e vigor das sementes. Considerando o exposto, o presente trabalho teve por objetivo avaliar a desinfestação superficial com álcool e hipoclorito de sódio, via tratamento de sementes, para o controle de Alternaria spp. e o desempenho fisiológico de sementes de cenoura. O trabalho foi desenvolvido no Laboratório Didático de Análise de Sementes Dr. Flávio Rocha FAEM-UFPel, no Laboratório de Patologia de Sementes e em canteiros preenchidos com areia. Os fatores estudados no experimento foram: método do papel filtro; testes de germinação; primeira contagem de germinação; envelhecimento acelerado; teste de frio sem solo; emergência a campo e comprimento de parte aérea e raiz. O delineamento experimental foi inteiramente casualizado, em esquema fatorial AxB (Fator A: hipoclorito e álcool, e Fator B: tempo (hipoclorito – 0 min; 2,5 min; 5,0 min; 7,5 min e 10,0 min) e (álcool – 0 s; 10 s; 20 s; 30 s; 40 s e 50 s), com quatro repetições. Conclui-se que a utilização de álcool 70% e solução de hipoclorito 1% para desinfestação superficial das sementes não alteram a qualidade fisiológica das sementes de cenoura, Além disso, ambas as soluções são eficazes para reduzir a infestação das sementes com Alternaria spp. Para álcool, uma melhor assepsia é obtida após 30 segundos de imersão. Para hipoclorito 1%, 7 minutos de imersão são necessários para uma melhor assepsia.
The future perspective of vegetable agribusiness in the world is timely, the growing participation of international market expansion opportunity in the domestic market. Within this context, there have been problems associated with the germination of carrot seeds as a result of fungal contamination. Therefore, the hypothesis of this study is that carrot seeds can be influenced in the germination process by presenting fungal contamination and surface disinfected with different treatments, they can promote better performance in germination and seed vigor. Considering the above, the present study was to evaluate the surface disinfection with alcohol and sodium hypochlorite, via seed treatment for the control of Alternaria spp. and the physiological performance of carrot seeds. The study was conducted at the Seed Analysis Laboratory Didactic Dr. Flavio Rocha FAEM-UFPel, at the Seed Pathology Laboratory and flower beds filled with sand. The factors studied in the experiment were: method of filter paper; germination; first count; Accelerated aging; cold test without soil; Emergency field and shoot length and root. The experimental design was completely randomized in a factorial arrangement AxB (Factor A: hypochlorite and alcohol, and Factor B: time (hypochlorite - 0 min, 2.5 min, 5.0 min, 7.5 min and 10.0 min) and (alcohol - 0 sec, 10 sec, 20 sec, 30 sec, 40 sec and 50 sec), with four replications. It follows that the use of 70% alcohol and 1% hypochlorite solution for surface disinfection of the seeds does not alter the physiological quality of carrot seeds. Moreover, both solutions are effective to reduce the infestation of seeds with Alternaria spp. For alcohol, a better sterilization is obtained after 30 seconds of immersion. 1% hypochlorite for seven minutes immersion is needed to better asepsis.
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Pinheiro, Rodrigo Trindade. "Superação da dormência de sementes e controle químico de cordas-de-viola (ipomoea spp.) em soja resistente ao glifosato". Universidade Federal de Santa Maria, 2010. http://repositorio.ufsm.br/handle/1/5034.
Testo completoAbstract (sommario):
Conselho Nacional de Desenvolvimento Científico e TecnológicoMorningglory is an annual plant reproduced by seeds. Seed germination occurs in streams during spring and summer making it difficult to control. Its occurrence has increased in soybean crops in southern states by the exclusive use of the herbicide glyphosate in weed control. This species has seed dormancy caused by impermeable to water, whose absorption is prevented by the seminal tegument. The possibility of using effective methods to overcome dormancy of seeds of bindweed would be ideal for studies of management of these species in agroecosystems as this would result in more uniform plant stands. This study aimed to: evaluate methods aimed at breaking dormancy of seeds of three species of morningglory, and investigate whether there are differences in dormancy between species of this weed (Chapter I); select alternative techniques in weed management prior to sowing of soybean by desiccation with glyphosate, alone and in combination with residual herbicides and selective culture, and also in post -emergency soybeans, with or without the application of glyphosate (Chapter II). In the experiment of scarification, sulfuric acid treatment (98%) resulted in increases in germination varies according to the species examined. Ipomoea undivided was less sensitive to treatment, for Ipomoea triloba, soaking the seeds for 10min in H2SO4 showed better germination. Already in Ipomoea purpurea, the response was linear and the best germination of this species occurred in time of 20min. Mechanical scarification enhanced germination of three species, because it promotes a break in the integument allowing more water uptake by seed. Soaking in KNO3 (0.2% v/v) promoted germination below 40% for the three species to morningglory. Seed exposure to radiation Ipomoea triloba ultrasound for 45 and 60 min resulted in germination percentage above 70%, but for Ipomoea purpurea and Ipomoea indivisa germination was below 50%. The results of experiment management of morningglory showed that the treatments applied in the pre-drying in soybean planting this species is not adequately controlled, controlling less than 80%. But the assessment at 14 DAT, treatments T3 (glyphosate + diclosulam) and T2 (glyphosate + clorimuron) controlled respectively 88 and 86%. In general, the highest grain yields were obtained when combining the treatments of drying with application of glyphosate V2 and V5 stages of soybeans, or just in V5, except for T1 (glyphosate - 720) and T4 (glyphosate + imazethapyr - 720 + 90). T3 (glyphosate + diclosulam - 720 + 25.2) stood out positively desiccation on pre-seeding, controlling the flow of seedling emergence in morningglory (81% at 28 DAT) and also in productivity grains (3.116 kg ha-1) when it was applied post-emergence glyphosate in soybeans. The application of the herbicide glyphosate has shown effective results in the management of morningglory. Therefore, it is necessary the use of combined applications of herbicides. The integrated management of weeds must not dismiss the use of herbicides, but control of the morningglory in soybean requires a management that includes addition of chemical control, several cultural practices, and therefore will require more investment by the producer but to have a greater return due to increased profitability.
A germinação das sementes de cordas-de-viola ocorre em fluxos durante a primavera e verão dificultando seu controle. As sementes apresentam dormência causada principalmente pela impermeabilidade do tegumento seminal à água. A possibilidade de se utilizar métodos eficazes na superação da dormência de sementes de cordas-de-viola é importante em estudos de manejo de Ipomoea spp. em agroecossistemas, pois resultaria em populações mais uniformes. Este trabalho teve por objetivos: (i) avaliar métodos capazes de superar a dormência de sementes de três espécies de cordas-de-viola e investigar se há diferenças na dormência entre as espécies desta planta daninha (Capítulo I) e (ii) selecionar alternativas de controle de cordas-de-viola antecedendo a semeadura da soja RR® através da dessecação com o herbicida glifosato, aplicado isolado e em associação com herbicidas residuais seletivos à cultura; e também em pós-emergência da soja RR®, com ou sem a aplicação do glifosato (Capítulo II). No experimento I (superação de dormência de sementes de cordas-de-viola), o tratamento com ácido sulfúrico (H2SO4) à 98 % resultou em incrementos na germinação das sementes variando de acordo com a espécie analisada. Ipomoea indivisa foi a espécie menos sensível ao tratamento; enquanto que em Ipomoea triloba , a imersão das sementes por 10min em H2SO4 apresentou melhor germinação. Já, em Ipomoea purpurea, a resposta foi linear e a maior percentagem de germinação ocorreu no tempo de 20min. A escarificação mecânica do tegumento seminal favoreceu a germinação das três espécies, pois promoveu uma ruptura no tegumento permitindo melhor embebição de água pela semente; enquanto que a imersão das sementes das três espécies de corda-de-viola em nitrato de potássio (KNO3) a 0,2% v/v, proporcionou germinações inferiores a 40 %. A exposição das sementes de Ipomoea triloba à radiação de ultrasom por 45 e 60min resultou em germinações das sementes maiores que 70%; porém para Ipomoea indivisa e Ipomoea purpúrea, a germinação foi inferior a 50%. Os resultados do experimento de manejo de cordas-de-viola em soja RR® (Capítulo II) mostraram que os tratamentos aplicados na dessecação em pré-semeadura da soja RR não controlaram satisfatoriamente esta planta daninha, com controles em geral inferiores 80 %; exceto nos tratamentos com as combinações de glifosato (720 g e.a. ha-1) com diclosulam (25,2 g i.a. ha-1) e glifosato (720 g e.a. ha-1) com clorimuron (20 g i.a. ha-1), onde os controles foram acima de 85%. Em geral, as maiores produtividades de grãos foram obtidas quando se associou os tratamentos de dessecação com a aplicação de glifosato em pós-emergência da soja RR nos estádios V2 e V5 ou apenas em V5; exceto para os tratamentos glifosato (720 g e.a. ha-1) e a combinação de glifosato (720 g e.a. ha-1) com imazetapir (90 g i.a. ha-1). O manejo de plantas daninhas em soja RR® não deve descartar o uso de herbicidas, porém o controle de cordas-de-viola necessita que se integre além do controle químico, outras práticas culturais, e consequentemente serão necessários mais investimentos pelo produtor, mas que terá retorno em função do aumento da rentabilidade por área.
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Silva, Érika Oliveira da. "Termoterapia e óleos essenciais no controle de Pseudomonas syringae pv. tomato". Universidade Estadual Paulista (UNESP), 2018. http://hdl.handle.net/11449/154931.
Testo completoAbstract (sommario):
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
A pinta bacteriana do tomateiro, causada por Pseudomonas syringae pv. tomato Okabe (Pst), é uma das principais doenças da cultura, pois pode reduzir a qualidade e o rendimento da produção, afetando o mercado de tomates frescos e transformados. A semente de tomate infectada por Pst, além de manter a bactéria viável por um longo período, também é importante por ser uma fonte primária de inóculo, justificando a necessidade de utilização de sementes isentas do patógeno. Desse modo, esse trabalho teve como objetivos avaliar a eficiência da termoterapia e da aplicação de óleos essenciais como alternativas para o tratamento de sementes de tomate, visando ao manejo de Pst. Inicialmente, foi verificada a ação in vitro dos óleos essenciais (OE) de citronela (Cymbopogon nardus (L.) Rendle), capim-limão (Cymbopogon citratus (DC.) Stapf), tomilho (Thymus vulgaris L.) e melaleuca (Melaleuca alternifolia Cheel), nas concentrações de 1%, 2% e 3%, utilizando-se leite em pó (LP - 1%) como emulsificante. Sulfato de estreptomicina (25mg/mL) e água esterilizada + LP foram incluídos como testemunhas. Os OE de tomilho (2 e 3%) e de citronela (nas três concentrações) e o sulfato de estreptomicina inibiram o desenvolvimento da colônia bacteriana, promovendo a formação do halo de inibição. Em seguida, foram conduzidos experimentos independentes, um para testar o tratamento de sementes com os OE selecionados (citronela a 1% e tomilho a 2%) e outro, com a termoterapia (50°C/30’ e 50°C/25’). Todos os experimentos foram realizados em duplicata. Foram avaliados a incidência de Pst nas sementes, a germinação e o vigor (altura de plantas). Todos os tratamentos testados promoveram a erradicação de Pst nas sementes. A presença de Pst nas sementes não interferiu na germinação destas, mas promoveu uma redução na altura das plantas. O tratamento com OE de tomilho resultou em redução significativa da germinação e do vigor. Os tratamentos térmico (ambas as combinações temperatura/tempo de exposição) e com óleo essencial de citronela a 1% mostraram-se alternativas viáveis para o manejo de Pst em sementes de tomate.
The bacterial speck of tomato, caused by the bacterium Pseudomonas syringae pv. tomato (Pst), is among the main diseases of this crop, as it can reduce the quality and production yield, affecting the market of fresh and processed tomatoes. Pstinfected tomato seed, besides maintaining the bacterium viable for a long period, is also important because it is a primary source of inoculum, demonstrating the need of using Pst-free seeds. Thus, the objective of this work was to evaluate the efficiency of thermotherapy and the application of essential oils as alternatives for tomato seeds treatment, aiming at the management of Pst. Initially, the essential oils (EO) of citronella, lemon grass, thyme and tea tree were evaluated in concentrations of 1%, 2% and 3% (powder milk (PM - 1%) was used as emulsifier). Streptomycin sulfate (25mg/mL) and sterile water + PM were included as controls. Thyme (2% and 3%) and citronella (at three concentrations) EO and streptomycin sulfate inhibited the bacterial colonies development, promoting inhibition halo the formation. Then, independent experiments were carried out, one to test the seed treatment with the selected EOs (citronella 1% and thyme 2%) and another with thermotherapy (50°C/30' and 50°C/25'). All experiments were performed in duplicate. The incidence of Pst in seeds, germination and vigor (plant height) were evaluated. All the tested treatments promoted the eradication of Pst in the seeds. Pst presence in the seeds did not interfere in seeds germination, but promoted a reduction in plant height. Treatment with thyme EO resulted in a significant germination and vigor reduction. Thermal treatments (both temperature/exposure time combinations) and 1% citronella EO were found to be viable alternatives for Pst management in tomato seeds.
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Sakoda, Jhessica Naomi. "Caracterização e controle da população de oócitos em bovinos Nelore baseados na configuração da cromatina". Botucatu, 2018. http://hdl.handle.net/11449/165182.
Testo completoAbstract (sommario):
Orientador: José Buratini JúniorResumo: Na produção in vitro (IVP), trabalha-se com uma população de oócitos heterogênea em relação ao estágio da maturação nuclear que estes oócitos se encontram, mais especificamente o estágio de vesícula germinativa (GV), uma vez que estes são obtidos de folículos em diferentes estágios de desenvolvimento. Visto que essa heterogeneidade impacta nos resultados da IVP, torna-se necessário que os processos de seleção de oócitos e de maturação in vitro sejam adequados e articulados, para que ocorra o desenvolvimento da competência oocitária para subsequente desenvolvimento. Neste estudo, objetivou-se avaliar a população de ovócitos obtida de folículos antrais grandes, testando a hipótese de que folículos dominantes saudáveis conteriam oócitos com grau intermediário de compactação da cromatina (oócitos em GV2). Em seguida, avaliou-se a população de oócitos obtida em dia aleatório do ciclo estral após OPU e testou-se o efeito de protocolo de sincronização combinando aspiração de folículos e tratamento com FSH para homogeneizar a população e controlar a qualidade dos oócitos. Os resultados sugerem que folículos dominantes saudáveis são predominantemente compostos por oócitos com níveis intermediários de compactação da cromatina e que protocolos de sincronização de aspiração do folículo combinadas ao tratamento com FSH podem ser úteis para controlar a qualidade do oócito para OPU / IVP.
Abstract: In vitro production (IVP), a heterogeneous oocyte population is employed in relation to the stage of nuclear maturation that these oocytes are found, more specifically the germinal vesicle (GV) stage, once they are obtained from follicles in different stages of development. Since this heterogeneity impacts the results of IVP, it is necessary that the processes of oocyte selection and in vitro maturation are adequate and articulated, so that occurs development of oocyte competence for subsequent development. The objective of this study was to evaluate the oocyte population obtained from large antral follicles, testing the hypothesis that healthy dominant follicles would contain oocytes with an intermediate degree of chromatin compaction (GV2 oocytes). Then we evaluated the population of oocytes obtained at random day of the estrous cycle after OPU and tested the synchronization protocol combining follicle aspiration and FSH treatment to homogenize the population and control the quality of oocytes. The results suggest that healthy dominant follicles are predominantly composed of oocytes with intermediate levels of chromatin compaction and that follicle aspiration synchronization protocols combined with FSH treatment may be useful to control oocyte quality for OPU / IVP.
Mestre
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GIRAUDEAU, RASSINOUX ISABELLE. "Contribution a l'etude du role du preconditionnement et des signaux moleculaires dans le controle de la germination des graines de striga hermonthica (del. ) benth. (scrophulariacee)". Nantes, 1997. http://www.theses.fr/1997NANT2038.
Testo completoAbstract (sommario):
Avant de devenir sensibles a un stimulant de germination, les graines de striga hermonthica doivent subir un preconditionnement dans des conditions externes precises, caracterisees notamment par un faible besoin en oxygene. La cinetique d'apparition de la sensibilite aux stimulants au cours du preconditionnement a ete etudiee. Selon la nature du stimulant de germination utilise, la sensibilite apparait entre le 2eme et le 5eme jour de preconditionnement et devient maximale entre le 8eme et le 10eme jour. Cette cinetique etant connue, les modifications physiologiques et metaboliques qui pourraient etre en rapport avec l'acquisition de la sensibilite ont ete recherchees. Ces modifications ne correspondent pas a l'activation d'une voie particuliere du metabolisme respiratoire. En effet, ce dernier, qui est caracterise par une respiration mitochondriale de faible intensite et une respiration residuelle importante, evolue peu au cours du preconditionnement. La respiration residuelle pourrait, en partie, correspondre a l'utilisation des lipides comme substrats respiratoires. D'autre part, l'apparition de la sensibilite aux stimulants est correlee avec la synthese de novo d'un certain nombre de polypeptides. La germination des graines preconditionnees, qui se produit en reponse a la perception d'un signal moleculaire provenant des exsudats racinaires de l'hote, peut egalement etre induite par certaines molecules xenobiotiques. L'action de ces differents stimulants s'exerce par l'intermediaire d'une synthese d'ethylene. Le role determinant de cette hormone dans le declenchement de la germination a ete demontre par l'utilisation des inhibiteurs de la synthese ou de l'action de l'ethylene et a l'aide de substances inhibant la transduction du signal hormonal. Enfin, l'addition des stimulants entraine une stimulation intense et immediate de l'activite respiratoire et tout specialement de la voie cytochromique.
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Cesarin, Anne Elise [UNESP]. "Efeito de maturadores sobre a germinação e crescimento inicial de corda-de-viola". Universidade Estadual Paulista (UNESP), 2014. http://hdl.handle.net/11449/113783.
Testo completoAbstract (sommario):
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000801896.pdf: 559676 bytes, checksum: dd33b174171860866d07ca337b8de314 (MD5)O desenvolvimento das cordas-de-viola, na cultura da cana-de-açúcar, ocorre na fase de maior crescimento dos canaviais. Após essa fase, inicia-se o processo de estabilização de seu crescimento e de maturação. Durante esse processo, as plantas de corda-de-viola apresentam vários fluxos de florescimento que normalmente, coincidem com a época de aplicação dos maturadores na cana-de-açúcar. Desta forma, espera-se que a aplicação de maturadores na fase reprodutiva destas plantas poderá reduzir a produção de frutos e sementes, por induzir o aborto floral e/ou ainda reduzir a viabilidade das sementes produzidas. Objetivo do trabalho foi avaliar o efeito de maturadores utilizados na cultura da cana-de-açúcar sobre a germinação de sementes, o desenvolvimento das plântulas e a abscisão de estruturas reprodutivas de Ipomoea hederifolia. O experimento foi conduzido no Departamento de Biologia Aplicado a Agropecuária, UNESP/Jaboticabal, SP, Brasil. Os tratamentos experimentais constituíram-se pela aplicação de cinco maturadores: ethyl-trinexapac, glyphosate, fluazifop-p-butyl, sulfometuron-metil, ethephon e uma testemunha sobre a espécie I.hederifolia, assim que a planta atingiu os estádios desejados. Após aplicação dos maturadores foram realizadas observações do numero de estruturas reprodutivas que sofreram abscisão determinando-se a porcentagem de abscisão das estruturas reprodutivas. Quando as sementes atingiram a maturidade de colheita foram coletadas e colocadas para germinar em placas de Petri determinando-se a porcentagem de sementes germinadas, o índice de velocidade de germinação e tempo médio de germinação. Em seguida mediu-se o crescimento inicial e, posteriormente massa seca. A aplicação de ethyl-trinexapac, glyphosate e fluazifop-p-butyl quando as plantas estavam com as flores abertas reduziu a viabilidade das sementes. O tratamento com glyphosate ...
The morning-glory development on sugarcane crop occurs in the phase of higher growth of sugarcane. After this stage, the sugarcane stops increasing its biomass and begins the maturation stage. During this stage, the morning-glory plants are in different development stages and it usually coincide with the time of ripeners application on sugarcane.The main of this research was to evaluate the effect of ripeners used in sugarcane crop on the seeds germination, seedling development and abscission of the reproductive structures of Ipomoea hederifolia. The experiment was carried out in UNESP/FCAV- Jaboticabal, SP, Brazil. It was apllied five ripeners (ethyl-trinexapac, glyphosate, fluazifop-p-butyl, sulfometuron-metil and ethephon) and one control (without ripeners) during the reproductive period of I.hederifolia. After ripeners application, were counted abscised reproductive structures to determine the percentage of abscission of reproductive structures. The seeds of each phonological stage were collected when it reached the point of physiological maturity and it was disposed to germinate in Petri dishes to evaluate the seed germination, germination time, germination rate, initial growth and dry mass weight. Ethyl-trinexapac, glyphosate e fluazifop-p-butyl application when plants are with open flowers can reduce seed viability. Glyphosate showed the smallest length value and it can affect seedling growth. Glyphosate and ethephon caused the highest percentages of abscission of I. hederifolia reproductive structures and, it can contribute to reducing the seeds inflow to the soils
Libri sul tema "Controlled germination"
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Schuster, Matthew D. Annual bluegrass (Poa annua L.) emergence under different residue management practices in perennial ryegrass and determination of resistant and susceptible annual bluegrass germination under controlled temperature and moisture. 1999.
Cerca il testo completoCapitoli di libri sul tema "Controlled germination"
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Geilfus, Christoph-Martin. "Effect of Germination Substrates on Tomato Plants". In Controlled Environment Horticulture, 215–23. Cham: Springer International Publishing, 2019. http://dx.doi.org/10.1007/978-3-030-23197-2_22.
Testo completo
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Hutzell, Michelle J., e Don J. Durzan. "Improved aseptic germination and controlled growth for micropropagation of Douglas fir". In Micropropagation of Woody Plants, 367–72. Dordrecht: Springer Netherlands, 1993. http://dx.doi.org/10.1007/978-94-015-8116-5_21.
Testo completo
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Basu, Sudipta, e Steven P. C. Groot. "Seed Vigour and Invigoration". In Seed Science and Technology, 67–89. Singapore: Springer Nature Singapore, 2023. http://dx.doi.org/10.1007/978-981-19-5888-5_4.
Testo completoAbstract (sommario):
AbstractSeed vigour is an important aspect of seed quality. It is a quantitative trait which is responsible for overall seed performance in terms of rate and uniformity of seed germination, seedling growth, emergence ability under unfavourable environments and post storage performance. Seed vigour is controlled by genetic factors, initial seed quality, production environments, harvesting and storage conditions. Seed vigour tests provide a more sensitive index of seed performance per se than the germination test. Efforts have been focused on developing novel or improving existing methods of vigour estimation in different crops. The vigour tests are tools routinely used for in-house seed quality control programs, especially for field and vegetable crops. Some treatments can improve seed vigour, although the treatment effects are more evident under sub-optimum than optimum growing conditions. This chapter deals with different aspects of seed vigour and its effects on plant growth and discusses physiological and biochemical parameters to understand underlying mechanisms.
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Zhang, Lei, e Jian-Jun Hu. "Transgenic poplar gene flow monitoring in China." In Gene flow: monitoring, modeling and mitigation, 56–70. Wallingford: CABI, 2021. http://dx.doi.org/10.1079/9781789247480.0004.
Testo completoAbstract (sommario):
Abstract Poplar is cultivated widely for pulpwood, firewood, and timber. Transgenic poplar may be part of a solution for wood demand in China. Because transgene escape is an important part of ecological security evaluation of transgenic plants, in this chapter we discuss a real transgenic poplar case study. In this case study, mature transgenic male Populus nigra plants harbored a Bacillus thuringiensis toxin gene (i.e. Bt poplar). A plantation of these plants served as a testbed for a relevant example for gene flow monitoring in China. Furthermore, we discuss environmental risk assessment (ERA) of these transgenic plants. While transgenes can drift to related species through natural and controlled pollination, the probability of transgene drift appears to be very low in the field. The resultantBt poplar seeds occurred at a frequency from about 0.15% at 0 m to about 0.02% at 500 m away from the Bt poplar. The Bt poplar progeny seeds had decreased germination within 3 weeks in the field (from 68% to 0%), compared with the 48% germination rate after 3 weeks at 4°C. The survival rate of seedlings in the field was 0% without any treatments, but increased to 1.7% under four combined treatments (clean and trim, watering, weeding, and cover with plastic to retain moisture) after being seeded in the field for 8 weeks. Hybrid offspring appeared to possess segregated traits following artificially controlled pollination. While hybrids of transgenic poplar and non-transgenic poplar can be excellent germplasm, gene flow should be monitored. Transgene expression in grafted scion and rootstock of transgenic poplar is reviewed. The transgenic poplar studied appears to be safe; no ecological or environmental harm has been observed in China.
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Goessnitzer, Florian, Joanna Jankowicz-Cieslak e Ivan L. W. Ingelbrecht. "In Vitro Plantlet Establishment of Coffea arabica from Cut Seed Explants". In Mutation Breeding in Coffee with Special Reference to Leaf Rust, 41–49. Berlin, Heidelberg: Springer Berlin Heidelberg, 2023. http://dx.doi.org/10.1007/978-3-662-67273-0_3.
Testo completoAbstract (sommario):
AbstractArabica coffee is one of the most important products in the world market. As a perennial crop, conventional breeding of Arabica coffee is challenged by its long reproductive cycle and narrow genetic base. In vitro tissue culture in combination with mutation induction techniques provides an attractive alternative approach for the genetic improvement of coffee. In this chapter we describe a simple and robust method to rapidly establish in vitro Arabica coffee plantlets from cut seed explants. The method streamlines the germination process under in vitro environmentally controlled conditions and overcomes microbial contamination, often associated with coffee seed lots harvested from the field or greenhouse. Using this protocol, disease-free in vitro coffee plantlets can be generated within 5–6 weeks, useful for downstream tissue culture manipulations such as the production of friable embryogenic callus and cell suspension cultures or induced chemical or physical mutagenesis.
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Geras'kin, Stanislav, Roman Churyukin, Polina Volkova e Sofiya Bitarishvili. "Using ionizing radiation for improving the development and yield of agricultural crops." In Mutation breeding, genetic diversity and crop adaptation to climate change, 424–32. Wallingford: CABI, 2021. http://dx.doi.org/10.1079/9781789249095.0043.
Testo completoAbstract (sommario):
Abstract The response of barley seedlings was studied after gamma irradiation of seeds with doses in the range of 2-50 Gy. It was shown that stimulation of plant growth occurred in the dose range of 16-20 Gy. The influences of the dose rate, the quality of seeds and their moisture on the manifestation of radiation effects were investigated. We studied, under controlled conditions, the activities of metabolic and antioxidant enzymes and observed an increase in their activity in the range of doses that cause stimulation of seedling growth. We showed that changes in the balance among different classes of phytohormones were probably involved in the acceleration of plant growth after irradiation of seeds using stimulating doses. Gamma irradiation of barley seeds significantly influenced the development of plants during the growing season. After irradiation with stimulating doses, we observed a reduction in the duration of the initial stages of ontogenesis; the phase of full ripeness occurred 5-7 days earlier than in the controls. The manifestation of the effect of irradiation depended on the conditions in which the plants developed. During the growing season of 2014, which was a dry year, plants originating from the irradiated seeds showed an increase in the number of productive stems, which led to an increase in yield by 34-38%; during the optimal 2015 season, an increase in the number of grains per spike caused an increase in yield by 8-29%. Therefore, our field study has shown that at least some hormetic effects can occur in the field. Irradiation of seeds can increase field germination, stimulate the growth and development of plants and increase their resistance to unfavourable environmental conditions. A more complete understanding of the underlying mechanisms of hormesis is needed to exploit its potential benefits in crop production.
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Herrmann, Sylvie, e François Buscot. "Why and How Using Micropropagated Trees rather than Germinations for Controlled Synthesis of Ectomycorrhizal Associations?" In Mycorrhiza, 439–65. Berlin, Heidelberg: Springer Berlin Heidelberg, 2008. http://dx.doi.org/10.1007/978-3-540-78826-3_22.
Testo completo
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Ding, Junzhou, e Hao Feng. "Controlled germination for enhancing the nutritional value of sprouted grains". In Sprouted Grains, 91–112. Elsevier, 2019. http://dx.doi.org/10.1016/b978-0-12-811525-1.00005-1.
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Baxter, E. D., M. O. Proudlove e C. J. Dawe. "Avoiding the use of pesticides and fumigants in barley storage". In European brewery convention, 85–92. Oxford University PressOxford, 1991. http://dx.doi.org/10.1093/oso/9780199632831.003.0009.
Testo completoAbstract (sommario):
Abstract An alternative is to use low oxygen atmospheres for the safe storage of barley, without applying either pesticides or fumigants. Small-scale trials with controlled atmospheres have shown no deleterious effects on germination or malting performance. In practice the use of combustion gases, low in oxygen, from a specially modified burner offers a safe and reliable method for storing malting barley.
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Maun, M. Anwar. "Seed germination and seedling establishment". In The Biology of Coastal Sand Dunes. Oxford University Press, 2009. http://dx.doi.org/10.1093/oso/9780198570356.003.0010.
Testo completoAbstract (sommario):
For the transformation of a seed to a seedling complex physical and biochemical changes occur within a seed before germination can proceed. Germination is controlled by diverse seed dormancy mechanisms in plant species that delays germination until the conditions are most favourable for seed germination and seedling establishment (Thompson 1970). Baskin and Baskin (1998) identified four benefits for the evolution of seed dormancy in plants: (i) persistence in risky environments as seed banks, (ii) decreased intraspecific competition, (iii) improved chances of seedling establishment and (iv) increased fitness (seed production) of the individual and the species as a whole. They showed that seed dormancy may be caused by any one of physiological, morphological, physical, chemical and mechanical constraints or by a combination of more than one of these factors. For instance, seeds may possess an embryo with a physiological inhibiting mechanism, immature embryo, impermeable seed coat or may contain chemical inhibitors and hard woody fruit walls. In all of these cases seed dormancy is eventually broken by one or more of the following treatments: after ripening, heat treatment, cold temperature stratification, prolonged exposure to high temperatures, exposure to light, softening of seed coat by microbes or physical scarification, leaching of inhibiting chemicals, ageing of seeds and other subtle changes in the habitat. In temperate North America with snow cover during winter months the seeds of a large majority of sand dune species—Cakile edentula, Ammophila breviligulata, Calamovilfa longifolia, Iva imbricata, Croton punctatus, Uniola paniculata—and others require cold stratification at <4°C for 4–6 weeks to break their dormancy requirements. Seeds of some species such as A. breviligulata and U. paniculata that require cold stratification at the northern end of their range lose this requirement in the south (Seneca 1972). At southern locations exposure to high temperatures may be required to fulfil the dormancy requirements. Winter annuals, Vulpia ciliata, Cerastium atrovirens, Mibora minima and Saxifraga tridactylites, that grow and mature their seeds in early summer on sand dunes at Aberffraw, North Wales, require exposure to high soil temperatures to overcome a state of dormancy in a certain proportion of seeds at the time of dispersal (Carey and Watkinson 1993; Pemadasa and Lovell 1975).
Atti di convegni sul tema "Controlled germination"
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Semenova, E. F., K. V. Vedernikova e E. Yu Schetneva. "In vitro culture of Nonea pulla DC. seeds." In CURRENT STATE, PROBLEMS AND PROSPECTS OF THE DEVELOPMENT OF AGRARIAN SCIENCE. Federal State Budget Scientific Institution “Research Institute of Agriculture of Crimea”, 2020. http://dx.doi.org/10.33952/2542-0720-2020-5-9-10-95.
Testo completoAbstract (sommario):
Nonea pulla DC. is a promising perennial medicinal plant growing in the Crimea. Controlled in vitro cultivation of nonea seeds allows improving the up-to-date techniques of seedlings preparation. The conducted experiments confirmed the low germinating capacity of seeds (5–9 %). To increase this parameter and to speed up the introduction process, we investigated the Nonea pulla in vitro culture. The initial phases of germination were expectedly observed during seeds cultivation. The seed swelling, rupture of pericarp and seed hull, release of germ with cotyledons, dehiscence of cotyledons were detected. Moreover, in some cases, no subsequent development was observed. However, normal germs formed in 60% of cases. Seeds also sprouted without the prior cold stratification. For the following growth, plants required a relatively simple culture medium. The maximum development conditions were reached after 1.0–1.5 months of in vitro cultivation (26±2 °С, illuminance of 2000–3000 lux, 16-hour photoperiod).
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Izadi, Mohammad, Betty Cepeda-Salgado e Seung I. Kam. "Mechanistic Modeling of Foam-Assisted EOR Simulations: Comparing Two Key Foam Generation Mechanisms". In Offshore Technology Conference. OTC, 2022. http://dx.doi.org/10.4043/31885-ms.
Testo completoAbstract (sommario):
Abstract Surfactant/foam enhanced-oil-recovery (EOR) processes have long been regarded as a practical means of overcoming subsurface heterogeneity and gravity segregation, leading to higher sweep efficiency and more cumulative oil recovery. In order to understand the outcome of such processes, modeling and simulating how foam propagates and behaves with the help of mechanistic foam models is crucial. There are largely two different versions of mechanistic foam models available in the literature, but no studies have been conducted to compare and contrast the two models within the context of the numerical calculation itself. To clarify, the two versions of foam models are based on different types of pore-scale lamella-creation events, both taking advantage of bubble population balance simulations. The first is established on the mobilization-and-division mechanism, implementing the mobilization pressure gradient (∇Po) in the model to produce a large population of bubbles in porous media. On the other hand, the second is formed on the Roof-type snap-off mechanism, incorporating convection-dependent bubble creation at the germination sites into the model. Therefore, this study investigates similarities and differences of the two different foam models and understand the pros and cons of each foam model. In line with that, this study is performed with the following tasks: (i) identify and borrow representative mechanistic foam models from the literature, (ii) make a fit to coreflood experimental data and determine foam model parameters for each model, and (iii) find the characteristics of the two models and their implications. The laboratory data for supercritical CO2 foam from Yin (2007) and Liu et al. (2010) is chosen to match (i) the pressure responses of no-foam/weak-foam state and strong-foam state and (ii) the steady-state pressure gradients (or drops) of strong foam state at various gas and liquid velocities. The models from Kovscek (1994) and Afsharpoor et al. (2010) are applied to perform the tasks. The results show that both models can reproduce experimental data equally nicely, but depending on how field operations are performed (rate-controlled vs. pressure-controlled) some additional sophisticated steps might be needed to make them equivalent in EOR simulations.
3
Hernández Moreno, Ángel, Rafael Hernández-Maqueda, Isabel Ballesterios e Carlos Torres-Miño. "Microwave drying of corn seeds: Effect of Temperature on Drying Time, Energy Consuption and Germination Rate". In Ampere 2019. Valencia: Universitat Politècnica de València, 2019. http://dx.doi.org/10.4995/ampere2019.2019.9831.
Testo completoAbstract (sommario):
Previous studies on the microwave drying of corn seeds have shown that the process parameters employed play a very important role in determining the properties and quality of this grain (Gürsoy et al, 2013). Among these parameters, the drying temperature has a fundamental role (Nair et al, 2011). The main objective of this work is to evaluate the effect of temperature on drying time, energy consumption and germination rate of corn seeds after they have been dried with microwave energy. To achieve the proposed objective, the drying process of these seeds was carried out in a rotating turntable domestic microwave oven (LACOR Model 69330), with a capacity of 30 liters and a total output power of 900 W, fitted with a PID temperature controller Eurotherm 3216 L. In this oven, 100 g of corn seeds, with an initial humidity of approximately 20%, was heated up to 3 drying temperatures (35, 55 and 75 °C). The seeds were weighed every 30 minutes and the drying process was considered completed when a humidity of 12 % was obtained. For each drying temperature studied, the experiments were carried out in duplicate. In each experiment, the electrical energy consumption was measured using a FLUKE 1735 energy analyzer. A sample of the dried seeds was subject to germination tests in a petri dish using filter paper and a volume of distillate water of 20mL to achieve sufficient humidity for them to sprout. Table 1 shows the average values obtained from the variables evaluated for each drying temperature. Table 1. Results of the microwave drying experiments of the corn seeds at different temperatures and their germination tests. Drying temperature (ºC) Drying time to reach a humidity of 12% (min) Energy consumption (Wh) Germination rate (%) 35 345,0 880,3 90,0 55 118,5 330,0 81,3 75 73,5 183,9 12,0 As can be seen in Table 1, the temperature exerts a significant influence on the drying process and the germination rate of the corn seeds. An increase in the drying temperature causes a simultaneous decrease in drying time (∿ 78%) and in energy consumption (∿ 79%), which are very positive aspects. However, there is also an unacceptable decrease (∿ 87%) in the germination rate of the corn seeds. References Gürsoy, S., Choudhary, R., Watson, D.G. Int. J Agric. & Biol. Eng., 2013, 6, 1, 90–99.Nair, G.R., Li, Z., Gariepy, Y., Raghavan, V. Drying Technology, 2011, 29, 11, 1291-1296.
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Cruz, Deisiane, Caio Rodrigues, João Maciel, Nilcilene Silva, Denmora Araujo, Otavio Chase e José Almeida. "Monitoring and Control System for Seed Germination Using Internet of Things". In X Workshop de Computação Aplicada à Gestão do Meio Ambiente e Recursos Naturais. Sociedade Brasileira de Computação - SBC, 2019. http://dx.doi.org/10.5753/wcama.2019.6416.
Testo completoAbstract (sommario):
This article presents an architecture of a reduced-size greenhouse, so-called mini-greenhouse monitored via Internet of Things (IoT). For this purpose, a prototype has been built with support of a computational system installed in its interior. So, sensors are used for monitoring and control of the variables that most influence in the development of a vegetal species. This text gives a brief description of the germination factors related on the various possibilities of its use. The proposed system has a cloud-based storage and the effective contributions of the computer system are started from the web platform, transfer the set-points to the controllers, and upload data read from sensors to the same web page.
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Hortnagl, Josef G., e John P. Parmigiani. "The Oregon State University Mini Malter". In ASME 2012 International Mechanical Engineering Congress and Exposition. American Society of Mechanical Engineers, 2012. http://dx.doi.org/10.1115/imece2012-86056.
Testo completoAbstract (sommario):
In the past 30 years the growing micro brewing community has stimulated research in the science of brewing beer. The Oregon State University (OSU) food science and crop science departments are resources for such research. There has existed a gap between the two departments that hinders the combination of their work. This gap is the production of malted barley, which is a key ingredient in beer. There currently exists no industry equivalent that can malt a batch size on a scale appropriate for the OSU food science brewery. This factor was the motivation for the mini malter project. This project was a collaborative effort between the schools of mechanical, industrial, manufacturing engineering and food science technology to design and build a prototype malting machine. The design chosen was a round stainless steel vessel for washing, steeping, germinating and kilning. Its main capability is incorporating all the different processes required for malting barley into a single machine. These multiple systems are controlled by a dedicated PC, data acquisition and conditioning hardware, and a custom LabVIEW program. After calibrating to produce malt similar to industry standard the mini malter has become a permanent addition to the food science department. The mini malter has also attracted interest from local brewers and barley farmers.
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Barateiro, Letícia Ganem Rillo Paz, Pedro Luiz Zonta De Freitas, Lilian Catarim Fabiano, Nilza Cristina Buttow e Jaqueline De Carvalho Rinaldi. "ALTERAÇÃO DA HISTOARQUITETURA TESTICULAR EM RATOS WISTAR APÓS ADMINISTRAÇÃO DE 5-FLUOROURACIL". In I Congresso Nacional Multidisciplinar de Oncologia On-line. Revista Multidisciplinar em Saúde, 2021. http://dx.doi.org/10.51161/rems/1574.
Testo completoAbstract (sommario):
Introdução: A quimioterapia com 5-fluorouracil (5-FU) promove diversos efeitos colaterais. Estudos anteriores demonstram que esse quimioterápico altera a morfologia dos túbulos seminíferos e possibilita a descamação do epitélio germinativo do testículo. Entretanto, há poucos dados sobre os impactos do 5-FU nesse órgão em dose e terapêutica semelhantes à prática clínica. Objetivo: Avaliar o impacto da administração de 5-FU na morfologia do testículo de ratos adultos. Material e métodos: O estudo foi aprovado pelo Comitê de Ética no Uso de Animais da Universidade Estadual de Maringá (protocolo: 4422140918). Foram utilizados 14 ratos Wistar machos, divididos em dois grupos (n=7): grupo controle (GC), administrado com solução fisiológica via intraperitoneal; grupo quimioterapia (G5-FU), administrado pela mesma via com 15 mg/kg de 5-FU por quatro dias consecutivos, 6 mg/kg por mais quatro dias alternados e dose final de 15 mg/kg. Esse esquema é semelhante ao utilizado para o tratamento dos cânceres: colorretal, mama, estômago, pâncreas, fígado, útero, ovário e bexiga. No 15° dia, todos os animais foram eutanasiados por superdosagem de Tiopental Sódico. O testículo foi dissecado, fixado em Methacarn e incluído em blocos de parafina. Cortes semi-seriados de 5 μm foram corados com Hematoxilina e Eosina para avaliação morfológica pelo método de Weibel. Por fim, realizou-se a estatística e os valores foram expressos em média (porcentagem) ± erro padrão. Resultados: Por análise comparativa, foi observado alteração significativa nos compartimentos epitelial (GC= 58,94 ± 0,52; G5-FU= 55,37 ± 0,52) e estromal (GC= 31,48 ± 0,60; G5-FU= 34,81 ± 0,63) do testículo após administração de 5-FU. Esses resultados sugerem a descamação epitelial dos túbulos seminíferos frente à quimioterapia. Apesar do modelo experimental diferente, nossos resultados corroboram com outros estudos na literatura. Conclusão: A quimioterapia com 5-FU em posologia semelhante à humana alterou a histoarquitetura testicular de ratos Wistar.
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Pereira, Vanessa de Brito, Gessilda De Alcantara Nogueira De Melo, Débora De Mello Gonçales Sant’ana e Jaqueline De Carvalho Rinaldi. "INFECÇÃO CRÔNICA POR TOXOPLASMA GONDII ALTERA O NÚMERO DE FOLÍCULOS OVARIANOS EM CAMUNDONGOS C57BL/6". In II Congresso Brasileiro de Saúde On-line. Revista Multidisciplinar em Saúde, 2021. http://dx.doi.org/10.51161/rems/1423.
Testo completoAbstract (sommario):
Introdução: Toxoplasmose é uma parasitose de ampla distribuição causada pelo Toxoplasma gondii. Esta zoonose pode causar abortos em várias espécies, além de desencadear alterações neurológicas e oculares, porém sabe-se pouco sobre seus efeitos nos órgãos da reprodução. Objetivo: Investigar o impacto da infecção crônica pelo T. gondii sobre a quantificação dos folículos ovarianos em camundongos adultos. Material e métodos: Camundongos c C57BL/6 fêmeas foram separadas nos grupos controle (GC, n=8) e infectado (GI, n=8). Enquanto o GC recebeu salina, o GI recebeu 1000 oocistos por gavagem para indução da infecção experimental (protocolo aprovado pela CEUA/UEM sob nº 4092040517). Após 60 dias houve análise do ciclo estral dos animais pelo smear vaginal e foram eutanasiados aqueles que se encontravam em estro, fase caracterizada pela presença de células epiteliais queratinizadas. Após o aprofundamento anestésico com vapor de isoflurano os eutanasiados tiveram os ovários dissecados, pesados, processados e incluídos em parafina. Cortes de 5µm foram corados em Hematoxilina-eosina para análise da morfologia geral da gônada e quantificação dos folículos ovarianos. Os resultados foram submetidos ao teste estatístico t student e considerados significativos quando p<0,05. Resultados: A infecção crônica pelo T. gondii não afetou o peso corpóreo ou do ovário dos animais. A gônada de ambos os grupos apresentou uma organização similar, contendo região cortical constituída por epitélio germinativo, túnica albugínea, tecido conjuntivo e folículos ovarianos em diferentes estágios de desenvolvimento. A região medular apresentou-se organizada em tecido conjuntivo contendo feixe vásculo-nervoso glandular. A análise quantitativa evidenciou um aumento em 32% no número de folículos totais na cortical ovariana do GI em relação ao GC (p<0,001). Sabe-se que o T. gondii é capaz de reduzir significativamente o FSH e o LH tanto em homens quanto mulheres. Assim, uma hipótese que justifica o resultado encontrado é de que o parasito foi capaz de promover desregulação hormonal e assim afetar a maturação folicular ovariana e a ovulação. Conclusão: A infecção crônica pelo T. gondii afetou a quantidade de folículos presentes no córtex ovariano, demonstrando que a infecção pelo parasito pode afetar os estágios mais precoces da reprodução em camundongos C57BL/6 fêmeas.
Rapporti di organizzazioni sul tema "Controlled germination"
1
Li, Li, Joseph Burger, Nurit Katzir, Yaakov Tadmor, Ari Schaffer e Zhangjun Fei. Characterization of the Or regulatory network in melon for carotenoid biofortification in food crops. United States Department of Agriculture, aprile 2015. http://dx.doi.org/10.32747/2015.7594408.bard.
Testo completoAbstract (sommario):
The general goals of the BARD research grant US-4423-11 are to understand how Or regulates carotenoid accumulation and to reveal novel strategies for breeding agricultural crops with enhanced β-carotene level. The original objectives are: 1) to identify the genes and proteins in the Or regulatory network in melon; 2) to genetically and molecularly characterize the candidate genes; and 3) to define genetic and functional allelic variation of these genes in a representative germplasm collection of the C. melo species. Or was found by the US group to causes provitamin A accumulation in chromoplasts in cauliflower. Preliminary genetic study from the Israeli group revealed that the melon Or gene (CmOr) completely co-segregated with fruit flesh color in a segregating mapping population and in a wide melon germplasm collection, which set the stage for the funded research. Major conclusions and achievements include: 1). CmOris proved to be the gene that controls melon fruit flesh color and represents the previously described gflocus in melon. 2). Genetic and molecular analyses of CmOridentify and confirm a single SNP that is responsible for the orange and non-orange phenotypes in melon fruit. 3). Alteration of the evolutionarily conserved arginine in an OR protein to both histidine or alanine greatly enhances its ability to promote carotenoid accumulation. 4). OR promotes massive carotenoid accumulation due to its dual functions in regulating both chromoplast biogenesis and carotenoid biosynthesis. 5). A bulk segregant transcriptome (BSRseq) analysis identifies a list of genes associated with the CmOrregulatory network. 6). BSRseq is proved to be an effective approach for gene discovery. 7). Screening of an EMS mutation library identifies a low β mutant, which contains low level of carotenoids due to a mutation in CmOrto produce a truncated form of OR protein. 8). low β exhibits lower germination rate and slow growth under salt stress condition. 9). Postharvest storage of fruit enhances carotenoid accumulation, which is associated with chromoplast development. Our research uncovers the molecular mechanisms underlying the Or-regulated high level of carotenoid accumulation via regulating carotenoidbiosynthetic capacity and storage sink strength. The findings provide mechanistic insights into how carotenoid accumulation is controlled in plants. Our research also provides general and reliable molecular markers for melon-breeding programs to select orange varieties, and offers effective genetic tools for pro-vitamin A enrichment in other important crops via the rapidly developed genome editing technology. The newly discovered low β mutant could lead to a better understanding of the Or gene function and its association with stress response, which may explain the high conservation of the Or gene among various plant species.