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1
李麗瑩 and Lai-ying Rosita Lee. "Genetic diversity and phylogenetic relationships of sweetclovers (Melilotus) germplasm resources." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 1999. http://hub.hku.hk/bib/B31221269.
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Lee, Lai-ying Rosita. "Genetic diversity and phylogenetic relationships of sweetclovers (Melilotus) germplasm resources /." Hong Kong : University of Hong Kong, 1999. http://sunzi.lib.hku.hk/hkuto/record.jsp?B21090208.
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Virchow, D. "Conservation of genetic resources : costs and implications for a sustainable utilization of plant genetic resources for food and agriculture /." Berlin ; New York : Springer, 1999. http://www.loc.gov/catdir/toc/fy0714/99012752.html.
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Harnal, Veera Kumari. "Population genetics and sperm physiology associated with genome resource banking in the Eld's deer." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1999. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape2/PQDD_0035/MQ64367.pdf.
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Settipalli, Satyaprakash R. "Synthetic seed production for germplasm storage of Hydrastis canadensis L. (goldenseal)." Morgantown, W. Va. : [West Virginia University Libraries], 2007. https://eidr.wvu.edu/etd/documentdata.eTD?documentid=5530.
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Thesis (M.S.)--West Virginia University, 2007.<br>Title from document title page. Document formatted into pages; contains vii, 48 p. : col. ill. Includes abstract. Includes bibliographical references (p. 40-42).
6
Carter, Michele R. "Gray leaf spot of corn : yield loss and evaluation of germplasm for resistance /." Thesis, This resource online, 1992. http://scholar.lib.vt.edu/theses/available/etd-10062009-020049/.
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Dukic, Snezana. "Development of an in vitro germplasm collection of Saccharum spp. hybrid clones." Thesis, Queensland University of Technology, 1995. https://eprints.qut.edu.au/36938/1/36938_Dukic_1995.pdf.
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An in vitro method for the establishment and storage of over 200 Saccharum spp. hybrid clones was developed that involved only 1 medium for shoot development and multiplication, without decontamination procedures. Apical buds from the axils of developing leaves surrounding the apical meristem were cultured on medium containing the plant growth regulators benzylamino purine and kinetin which regenerated multiple shoots. Shoots transferred to a medium containing naphthalene acetic acid and 60 g L"1 sucrose, developed roots. In vitro plants were transferred to a half strength Murashige and Skoog medium without plant growth regulators and placed in storage at 18°C. After 12 months of storage plants were transferred to a fresh medium and returned to storage. The genetic integrity of clones based on phenotypic assessment and isozyme patterns was not affected by in vitro culture after 3, 6 and 12 months storage at l 8°C.
8
Lochen, Tobias. "Die völkerrechtlichen Regelungen über den Zugang zu genetischen Ressourcen /." Tübingen : Mohr Siebeck, 2007. http://bvbr.bib-bvb.de:8991/F?func=service&doc_library=BVB01&doc_number=016140557&line_number=0001&func_code=DB_RECORDS&service_type=MEDIA.
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Edwards, Catriona Helen. "Drug target identification in the cat flea by transcriptomics and gene knockdown." Thesis, University of Aberdeen, 2018. http://digitool.abdn.ac.uk:80/webclient/DeliveryManager?pid=236461.
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Ctenocephalides felis is a major pest of companion animals worldwide. This project aimed to generate novel genetic resources for C. felis and develop tools to aid drug-target identification and validation. Sample handling methods were assessed and candidate reference genes validated, to ensure quality of RNA samples and reliable gene expression normalisation. Piercing C. felis samples prior to storage in RNAlater ensured RNA integrity was maintained over time. Glyceraldehyde 3-phosphate dehydrogenase , 60S ribosomal protein L19 and elongation factor-1α were demonstrated as stable reference genes across all comparisons tested. A C. felis transcriptome encompassing multiple developmental stages, sexes and tissues was sequenced and de novo assemblies produced with two assemblers, Trinity and Oases. Each assembly contained >100000 contigs. Annotation of the assemblies generated functional insight, such as top BLAST hits, GO annotations and signal peptide predictions. The Trinity assembly was deemed the highest quality and searched for genes of interest, involved in development. Expression analysis of selected transcripts across stadia gave insight into developmental processes, and demonstrated the utility of the transcriptome. This study was the first to demonstrate that C. felis can mount an RNAi response upon exposure to dsRNA. Knockdown of glutathione S-transferase σ (GSTσ), was demonstrated in adult C. felis: ≈80 % knockdown following microinjection of dsGSTσ; ≈64 % knockdown after soaking in dsGSTσ; ≈96 % knockdown after continuous feeding on dsGSTσ. RNAi machinery was identified in C. felis. siRNAi pathway components, Dicer 2 and Argonaute 2, were upregulated following dsRNA exposure. Dicer 2 was knocked-down by soaking in dsDicer2, although results of an “RNAi of RNAi” experiment were inconclusive. Transcripts encoding machinery putatively involved in dsRNA uptake and breakdown were also identified. Through these studies, this project has generated novel insights into C. felis biology and opened up new avenues for research.
10
Reid, Lana M. "Resistance of world germplasm resources of maize, Zea mays, to the European corn borer, Ostrinia, nubilalis." Thesis, University of Ottawa (Canada), 1988. http://hdl.handle.net/10393/5518.
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Dajani, Ola Fouad. "Genetic resources under the CBD and TRIPS : issues on sovereignty and property." Thesis, McGill University, 2002. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=78178.
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Coming together to save the Earth. Ten years have passed since the Earth Summit in Rio created such passion and expectations. Whether the Convention on Biological Diversity has met those expectations or not vary from person to person.<br>Evidently, the Convention on Biological Diversity is complex, not only in its language, but also in its attempt to balance between conservation and sustainable use, and between the providers of and benefiters from biological diversity.<br>Subsequent to its conclusion, the Parties have strived to achieve these objectives. This thesis attempts to assist in this process by exploring the means of implementing the Convention on Biological Diversity and their consequences.<br>The scope of the thesis is limited to the matters of sovereignty rights and access to genetic resources, in an effort to clear up the uncertainties in the applications of these components. This thesis attempts to contribute a pragmatic perspective to these matters, which, at their core, rely on the crossing points in the implementation of the Convention on Biological Diversity and the Agreement on Trade-Related Aspects of Intellectual Property Rights. This thesis focuses on ways to reconcile property rights in genetic resources with patent rights in invention using genetic resources. It proposes one interpretation of property rights in genetic resources so as to avoid any conflict with patent rights and accordingly, avoid conflict between the requirements of the Convention on Biological Diversity and those of the Agreement on Trade-Related Aspects of Intellectual Property Rights.<br>I hope that the views and proposals expressed in this thesis will be considered along with other diverse approaches to the implementation of the Convention on Biological Diversity.
12
Sharma, Santosh. "Increasing the Genetic Diversity of U.S. Northern Corn Belt Hybrids with Tropical and Temperate Exotic Germplasm." Thesis, North Dakota State University, 2011. https://hdl.handle.net/10365/29319.
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The NDSU EarlyGEM or the Early Germplasm Enhancement of Maize (Zea maize L.) is a
long term incorporation program designed to increase the genetic diversity of short season
hybrids. Starting in 1999, exotic GEM breeding crosses derived from temperate accessions:
BR52051, CH05015; tropical accessions: SCR01, CUBA17, FS8B; and tropical hybrid
DKB844 along with late checks: B73, Mo17, and Iowa Stiff Stalk Synthetic (BSSS), were
adapted to short-seasons and incorporated via a modified backcross (BC) procedure. This
study was designed to assess the genetic diversity in exotic derived BC1:S1 lines and their
competitive potential as sources of new and unique hybrids. Useful genetic diversity was
evaluated with testers belonging to opposite heterotic groups, LH176 representing a non
stiff stalk and TR3026 x TR2040 a stiff stalk testers and were tested in five North Dakota
environments over two years (2009 and 2010). All the traits showed highly significant
(P<0.01) differences across genotypes except root and stalk lodging. Among 236
experimental testcrosses, 64 were statistically not different (LSD, 0.05) to industry hybrids
for grain yield. BC derived lines from BR52051, CHO5015, DKB844 showed diverse
alleles for low grain moisture (below 87 relative maturity days) at harvest and high grain
yield. SCR01, BR52051, CHO5015 and CUBA117 derived lines produced hybrids with
high grain oil (4. 9% vs. 4.1%) and grain protein (10.4% vs. 9.1%) contents compared to
top checks. The results showed that the exotic incorporations are the sources of unique new
alleles for early maturing maize not present in existing US germplasms (e.g. B73, Mo17, and BSSS). Even though each exotic cross was unique to integrate diverse alleles, utilizing multiple unique exotic crosses for incorporation showed large variation for specific traits. Phenotypic correlations of traits showed grain moisture played the most important role for short season hybrid development. Exotic incorporation through NDSU EarlyGEM has shown a new way of breeding early maturing maize keeping the breeding program open and genetic diversity high.
13
Souch, Graham Robert. "Long-term conservation of Allium germplasm resources : the cryopreservation of A. sativum using an encapsulation/dehydration approach." Thesis, University of Derby, 2006. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.433865.
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Salinas-Flores, Liliana, and n/a. "Understanding and improving the cryopreservation of pacific oyster (Crassostrea gigas) oocytes via the use of two approaches : modification of an existing cryopreservation protocol and manipulation of the lipis fraction of the oocytes." University of Otago. Department of Food Science, 2008. http://adt.otago.ac.nz./public/adt-NZDU20080305.143446.
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Cryopreservation of gametes is a valuable tool for the fast-growing aquaculture industry in New Zealand. In the present study, research was aimed to improve the cryopreservation of Pacific oyster (Crassostrea gigas) oocytes. For this, two main approaches were used: the modification of an existing published (standard) cryopreservation protocol for oyster oocytes and the modification of the oocytes themselves prior to cryopreservation. The objectives in the chapters of this thesis were: (a) determination of the cryobiological characteristics of oyster oocytes; (b) assessment and reduction of intracellular ice formation (IIF) in oocytes; and (c) modification of the lipid fraction (cholesterol and fatty acids) of oocytes prior to cryopreservation.
Knowledge of the membrane permeability parameters in response to concentrations of water and ethylene glycol (EG), the influence of temperature upon these parameters, and the osmotic tolerance limits of oyster oocytes were used to develop computer models that simulated the cellular volume changes that oocytes underwent during EG addition and removal. The models predicted that when one part of EG was added in one step to one part of oocyte suspension and equilibrated for 20 min at 20 �C, similar volume changes in oocytes would be obtained, compared to a more complicated multi-step addition method. This method of addition resulted in similar post-thaw fertilization rates to those obtained by using the multi-step addition method, thus reducing oocyte handling.
Cryomicroscopy was used to assess the effect of cooling rates and EG concentration on the temperature at which oocytes underwent IIF. It was found that IIF occurred at higher subzero temperatures when fast cooling rates were used (30 and 5 �C min⁻�) and at EG concentrations ranged between 0 and 15%. At a relatively slower cooling rate of 0.3 �C min⁻� and with 10% EG, which are the conditions employed in the standard cryopreservation protocol, no IIF occurred.
The steps of the standard protocol that were more likely to cause oocyte damage were identified by evaluating the fertilization rate of oocytes at each step. Results showed that oocytes were most damaged by cooling them to -35 �C and followed by plunging them in liquid nitrogen. Contrary to what had been observed under the cryomicroscope, transmission electron microscopy (TEM) analysis revealed that all oocytes cryopreserved by the standard protocol contained cytoplasmic ice. In addition, it was also observed that oocytes were at two developmental stages when frozen (prophase and metaphase I). These observations prompted the development of alternative cooling programmes aimed to reduce intracellular ice. The effect of cooling rate, plunge temperature and time held at the plunge temperature were thus evaluated, based on post-thaw fertilization rate of oocytes. Overall, neither the cooling rate nor the holding time had an effect on oocyte fertility. However, the plunge temperature had an effect, where oocytes plunged at -60 �C had lower post-thaw fertilization rates than oocytes plunged at -35 �C. Through the slowing of the cooling rate, lengthening of the holding time and lowering of the plunge temperature, it was possible to reduce the amount of ice in the cytoplasm. However, the reduction of intracellular ice did not improve the post-thaw fertilization rate of the oocytes; on the contrary, post-thaw fertilization decreased notoriously. From these results, it can be suggested that oyster oocytes are more likely to be damaged by exposure to high intra and extracellular solute concentration than IIF during cryopreservation.
In an effort to modify the lipid content of oyster oocytes prior to cryopreservation and thus, making them more resistant during cryopreservation, oocytes were incubated in solutions that would add or remove cholesterol or in solutions rich in long chain fatty acids (EPA or DHA). Oocytes incubated in cholesterol-rich solutions showed a positive uptake of fluorescently labelled cholesterol and this effect was dose dependent. Nevertheless, this uptake did not improve the post-thaw fertilization rate nor did it increase the total cholesterol content of the oocytes. When oocytes were incubated in non-conjugated or conjugated EPA or DHA, no increase in the proportion of these fatty acids was identified in the fatty acid profiles of whole oocytes and no improvement of the post-thaw fertilization rate was recorded.
Given that there was no uptake of fatty acids from the incubation media by the oocytes, a different approach was taken. This involved the supplementation of lipid-rich diets to the oyster broodstock during gametogenesis (cold-conditioning) and vitellogenesis (warm-conditioning). Despite results showing that lipid content and, indeed, fatty acid profile was altered through the diet, the results also showed that fresh oocytes from broodstock fed during cold-conditioning did not show any improvement in their fertilization rates, nor did they benefit from a lipid-rich diet during warm-conditioning. On the other hand, cryopreserved oocytes did have higher post-thaw fertilisation rates when broodstock were fed during cold-conditioning and, although no effect was found from feeding broodstock with either of the lipid-rich diets during warm-conditioning, trends indicated that a diet consisting of fresh microalgae or the commercial supplement Algamac would yield the highest post-thaw fertilization rates.
This thesis has furthered the understanding of some of the factors that determine cryosurvival in oyster oocytes and has demonstrated that both physical and biological issues must be taken into consideration for cryopreservation. Specifically, the results in this thesis helped to modify an empirically developed cryopreservation protocol for Pacific oyster oocytes. In addition, the results also showed strong evidence of the survival of oyster oocytes to intracellular ice and highlighted the importance of supplying the broodstock with lipid-rich food during the periods of gamete formation and maturation in order to obtain oocytes that are more amenable to cryopreservation. These benefits could be of significant practical importance and may be extended for the development or refinement of cryopreservation protocols for other shellfish species of commercial importance to the aquaculture industry of New Zealand.
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Martins, Diego Albino. "Caracterização molecular de acessos de jabuticabeiras do banco ativo de germoplasma da UTFPR com marcadores microssatélites." Universidade Tecnológica Federal do Paraná, 2013. http://repositorio.utfpr.edu.br/jspui/handle/1/702.
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O Brasil é país detentor de grande biodiversidade, no entanto pequena parcela
dessa já foi estudada e catalogada. Os recentes avanços antrópicos sobre os
ecossistemas naturais tem levado a sua rápida fragmentação e eliminação de alguns
biótipos ainda não estudados ou catalogados. Nessa realidade de erosão genética
acelerada encontra-se também espécies de jabuticabeira (Plinia sp.) que são
endêmicas do Centro Sul/Sudoeste do Paraná, no ecossistema Floresta com
Araucária. Medidas de conservação de germoplasma para uso atual e futuro, bem
como táticas de manejo e conservação dos recursos naturais são preponderantes
para reduzir ao mínimo os danos causados a biodiversidade brasileira. Para tanto é
necessário entender a diversidade genética existente nos ecossistemas naturais,
que é o insumo básico para a sobrevivência e evolução entre os indivíduos frente as
modificações ambientais. No presente trabalho foi realizado a caracterização
genética de 110 jabuticabeiras que constituem o banco ativo de germoplasma desta
espécie na UTFPR – Câmpus Dois Vizinhos. Foi possível identificar a
transferibilidade de 9 marcadores moleculares microssatélites (SSR) com caráter
polimórfico para a população estudada, e realizar a padronização de reação de PCR
para cada um deles. Da análise das jabuticabeiras do banco ativo de germoplasma
chegou-se a conclusão de que o mesmo abrigou valor considerável de diversidade
alélica. No entanto tal diversidade está mal distribuída, já que 11 indivíduos sozinhos
já são capazes de representar 59,2% de todos alelos da coleção de 110 plantas. Os
valores encontrados de heterozigosidade observada e conteúdo informativo (PIC)
nessa subpopulação de 11 indivíduos foram superiores aos valores encontrados
para o conjunto integral do banco ativo. O agrupamento dos indivíduos mostrou a
existência de 8 diferentes grupos, sendo que 89 indivíduos ficaram no grupo 1,
demonstrando o seu possível grau de parentesco e baixo nível de diversidade
genética.<br>Brazil is a country of great biodiversity holder, however small portion of that has been
studied and cataloged. Recent advances human activities on natural ecosystems has
led to its rapid fragmentation and elimination of some biotypes still, not it studied or
cataloged. In this reality of genetic erosion is also accelerated jabuticaba tree species
(Plinia sp.). That are endemic from South Central / Southeastern Paraná State, in
Araucaria forest ecosystem. Germplasm conservation measures for current and
future use, as well as tactics for management and conservation of natural resources
are crucial to minimize the damage caused to Brazilian biodiversity. So it is
necessary to understand the genetic diversity in natural ecosystems, which is the
basic input for the survival and evolution among individuals facing environmental
changes. In the present study was to characterize genetic of 110 jabuticaba tree fruit,
that constitute the germoplasm bank of jabuticaba tree fruit from UTFPR - Câmpus
Dois Vizinhos. It was possible to identify transferability of 9 microsatellite markers
(SSR) with polymorphic character for the population studied, and it carry out
standardization of PCR reaction for each of them. The analysis of plant germoplasm
bank came to the conclusion that houses a considerable amount of allelic diversity,
but this diversity is poorly distributed, since 11 individuals alone are already able to
represent 59.2% of all alleles of the collection of 110 plant. The found values of,
observed heterozygosity and information content (PIC) in this subpopulation of 11
individuals were higher than the values found for the full set of the germoplasm bank.
The grouping of individuals showed the existence of 8 different groups, and 89
subjects were in group 1, demonstrating a possible relationship and low level of
genetic diversity.
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Siu, Lai-ping, and 蕭麗萍. "Conservation and in vitro propagation of Hong Kong Camellias." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 1992. http://hub.hku.hk/bib/B31210545.
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Albuquerque, Marcos Roberto. "Avaliação de variabilidade genética e química em cunila spicata Benth." reponame:Repositório Institucional da UCS, 2004. https://repositorio.ucs.br/handle/11338/1405.
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Cunila spicata Benth. é uma planta aromática e medicinal utilizada popularmente no sul do Brasil como béquica, peitoral e sudorífera, e que apresenta comprovada atividade antiviral e anticonvulsiva. C. spicata é uma das 12 espécies sul-americanas do gênero Cunila (Lamiaceae) sendo encontrada em banhados e borda de mata de galeria no sul do Brasil, Argentina e Uruguai. Dentro deste contexto, no presente trabalho foi avaliada a variabilidade genética e química de populações de C. spicata coletadas nas regiões nordeste e sudeste do Rio Grande do Sul, com vistas a formação de bancos de germoplasma, determinação de estratégias de preservação e uso sustentável. Os marcadores ISSR e RAPD mostraram-se eficientes na determinação de variabilidade genética desta espécie, permitindo a identificação de todas as populações e indivíduos avaliados. As populações de C. spicata caracterizam-se como grupos geneticamente estruturados. Entretanto, não foi constatada formação de agrupamentos dentro da espécie, nem relação entre as distâncias genéticas e geográficas, ou entre as populações originarias das duas regiões geográficas amostradas. Por outro lado, a análise da composição dos óleos essenciais das 10 populações permitiu separar as mesmas em dois quimiotipos caracterizados por elevada concentração de α-terpineol/limoneno, e linalol, respectivamente. As populações da região sudeste enquadraram-se dentro do quimiotipo linalol, enquanto as da região nordeste no quimiotipo α-terpineol/limoneno. A relação geográfica e química é indicativa da existência de pressão de seleção quanto ao tipo de óleo essencial da região de ocorrência.<br>Submitted by Ana Guimarães Pereira (agpereir@ucs.br) on 2016-12-01T16:00:30Z
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Previous issue date: 2016-12-01<br>Conselho Nacional de Desenvolvimento Científico e Tecnológico, CNPq.<br>Cunila spicata Benth. is a medicinal and aromatic plant popularly used in South Brazil as bequic, expectorant and sudiriferous, and that has confirmed antiviral and anti-convulsive activities. C. spicata is one of the 12 South-American species of the genus Cunila( Lamiaceae) been currently found in swamps and borders of gallery forests in South Brazil, North Argentina and Uruguay. In this context, the present work aimed to evaluate the genetic and chemical variability of C. spicata populations collected at the northeast and southeast regions of Rio Grande do Sul, to subside the construction of a germplasm bank, to determine conservation strategies, and to develop a sustainable use of this species. ISSR and RAPD markers proved to be efficients for the determination of the genetic variability of this species, allowing the identification of all the populations and individuals. C. spicata populations were characterized as genetically structured groups. However, clusters within the species were not evident, and no relations were detected between geographic and genetic distances, or between populations of the two regions. Conversely, the analysis of essential oil composition allowed the populations in two chemotypes, characterized by high concentration of α-terpineol/limonene, and linalool, respectively. The populations of the southeast region belong to the linalool chemotype, and those from the northeast region to the a-terpineol/limonene chemotype. This geographical and chemical relation is indicative of different selection pressures in the two regions.
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Heider, Bettina. "Assessment of legume diversity for genetic resources conservation in the highlands of Northeast Vietnam germplasm collecting, molecular marker studies and ethnobotanical surveys." Beuren Stuttgart Grauer, 2007. http://d-nb.info/989892956/04.
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Chang, Yunsheng. "Evaluation of immunological techniques for host fish identification, and cryopreservation of embryos for conserving rare freshwater mussels." Thesis, This resource online, 1993. http://scholar.lib.vt.edu/theses/available/etd-12052009-020208/.
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Reif, Jochen. "Assessing the genetic diversity in crops with molecular markers theory and experimental results with CIMMYT wheat and maize elite germplasm and genetic resources /." [S.l. : s.n.], 2004. http://www.bsz-bw.de/cgi-bin/xvms.cgi?SWB11406735.
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Bruckner, Adam Wesley. "AFLP-based Genetic Diversity Assessment of Global Sweetpotato (Ipomoea batatas (L.) Lam.) Germplasm Resources: Progress Toward The Development of a Sweetpotato Core Collection." NCSU, 2004. http://www.lib.ncsu.edu/theses/available/etd-08172004-152323/.
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Sweetpotato (Ipomoea batatas (L.) Lam) is an extremely diverse and important crop ranking seventh in terms of global production. It is grown throughout the world as a staple crop, and is particularly important in tropical developing countries due to its wide adaptability as well as its enormous potential for preventing malnutrition. The International Potato Center (CIP) in Lima, Peru and the USDA-ARS Plant Genetic Resources Conservation unit (PGRCU) in Griffin, Georgia are the most important sweetpotato gene banks worldwide. Roughly 7,000 and 750 accessions are present in each, respectively. Both collections have been characterized for many phenotypic traits of economic importance, and they are very important in terms of germplasm conservation, as they represent a vital resource for breeders seeking future genetic improvement of sweetpotato. The molecular genetic diversity present in each collection, however, is poorly understood. In this study, 775 accessions from the PGRCU collected from various countries were sampled and fingerprinted using AFLP markers derived from 10 primer pair combinations. A total of 183 polymorphic and clearly scorable bands were generated. Using polymorphisms and phylogenetic software (PAUP and NTSysPC), we were able to clearly distinguish a different banding pattern for each of the 775 accessions. A Neighbor-Joining phylogram was constructed and revealed 6 base clades with no region specificity. Analysis of molecular variance (AMOVA) was carried out using the software program Arlequin. The within-region variation at 97.94% was the major source of molecular variance. Pairwise genetic distances between regions were calculated and the smallest distance was between the Caribbean and Central America and the greatest distance was between the Pacific Islands and South America. Principle coordinate analysis (PCO) was performed by NTSysPC and several clusters of germplasm were noted. This research indicates that there is an abundance of genetic diversity present in sweetpotato.
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Mason, Nicholas Craig. "Forging a New Global Commons Introducing common property into the global genetic resource debate." Thesis, University of Canterbury. School of Political Science and Communication, 2004. http://hdl.handle.net/10092/904.
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This thesis provides an analysis of recent attempts to regulate the governance of genetic resources through the initiation of new global commons regimes. These attempts have arisen out of a combination of the growing recognition of genetic resources' value and global nature; a new resurgence in support for the common property paradigm; and, during a period in which the world is becoming increasingly globalised, with many governance competencies moving to the supranational level. They can be viewed as part of a broader effort to proffer the common property approach as a legitimate alternative in the property regime debate: a debate that has increasingly become trapped in the public-private dichotomy at the dawn of the twenty-first century. The aim of this thesis is to investigate the success of these attempts, and offer suggestions about how future attempts might be more successful. While there are a multitude of books, articles, opinion pieces and media reports produced that concern themselves with property theory, intellectual property theory, the efficacy or morality of applying property regimes to living materials, and the threats and promises of globalisation, all of which influence the notion of a potential global genetic commons, relatively little has been written directly on the idea of applying global common property regimes to genetic resource governance issues. The first part of this thesis constructs a theory of a global genetic commons, drawing inspiration from a variety of sources, while the second part tests this theory in order to analyse the outcomes of the recent attempts, and suggest directions for future research. The thesis finds that the conception of a global genetic commons is indeed a valid one, and that while not all attempts so far have been successful, the common property paradigm does offer valuable insights for the future governance of genetic resources at the global level.
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Marconato, Marcela Bonafin [UNESP]. "Diversidade fenotípica por meio de caracteres agronômicos em acessos de soja." Universidade Estadual Paulista (UNESP), 2014. http://hdl.handle.net/11449/122011.
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000817675.pdf: 435803 bytes, checksum: 9790ca90cd43e847593a2eb809ac5ab5 (MD5)<br>A soja destaca-se como a oleaginosa de maior importância no mundo, tendo em vista sua relevância nutricional e econômica. Devido ao aumento da área cultivada e, consequentemente da produtividade, o Brasil atualmente, é considerado o maior exportador de soja. No entanto, observa-se que a base genética da soja é restrita, devido à indisponibilidade de alelos capazes de enfrentar estresses bióticos e abióticos de forma totalmente eficiente. Desta forma, os programas de melhoramento visam aumentar a variabilidade genética para o desenvolvimento de cultivares mais produtivas e adaptadas. Estudos a respeito de novas fontes de germoplasma, como as Plant Introductions – PIs, tornam-se necessários para a identificação de características agronômicas de interesse para os melhoristas. Sendo assim, o presente trabalho possui como objetivo geral a avaliação do desempenho agronômico e a divergência genética de 93 acessos de soja, pertencentes a um painel de diversidade visando a obtenção de dados que possam ser utilizados no incremento de programas de melhoramento de soja brasileiros<br>Soybean stands out as the most important oilseed in the world, given its nutritional and economic importance. Due to increased acreage and hence productivity, today, Brazil is the largest exporter of soybeans. However, it is observed that the genetic basis of soybean is restricted due to the unavailability of alleles able to cope with biotic and abiotic stresses fully efficiently. Thus, breeding programs aimed at increasing the genetic variability for the development of more productive and adapted cultivars. Studies regarding new sources of germplasm, such as Plant Introductions - PIs, become necessary for the identification of agronomic traits of interest to breeders. Therefore, the present work has as main objective the evaluation of agronomic performance and the genetic diversity of 93 accesses of soybean, belonging to a panel of diversity in order to obtain data that can be used in the growth of Brazilian soybean breeding programs
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Persson, Helena. "Estimating genetic variability in horticultural crop species at different stages of domestication /." Alnarp : Swedish Univ. of Agricultural Sciences (Sveriges lantbruksuniv.), 2001. http://epsilon.slu.se/avh/2001/91-576-5838-2.pdf.
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Marconato, Marcela Bonafin. "Diversidade fenotípica por meio de caracteres agronômicos em acessos de soja /." Jaboticabal, 2014. http://hdl.handle.net/11449/122011.
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Orientador: Sandra Helena Unêda Trevisoli<br>Banca: Everlon Cid Rigobelo<br>Banca: Viviane Formice Vianna<br>Resumo: A soja destaca-se como a oleaginosa de maior importância no mundo, tendo em vista sua relevância nutricional e econômica. Devido ao aumento da área cultivada e, consequentemente da produtividade, o Brasil atualmente, é considerado o maior exportador de soja. No entanto, observa-se que a base genética da soja é restrita, devido à indisponibilidade de alelos capazes de enfrentar estresses bióticos e abióticos de forma totalmente eficiente. Desta forma, os programas de melhoramento visam aumentar a variabilidade genética para o desenvolvimento de cultivares mais produtivas e adaptadas. Estudos a respeito de novas fontes de germoplasma, como as Plant Introductions - PIs, tornam-se necessários para a identificação de características agronômicas de interesse para os melhoristas. Sendo assim, o presente trabalho possui como objetivo geral a avaliação do desempenho agronômico e a divergência genética de 93 acessos de soja, pertencentes a um painel de diversidade visando a obtenção de dados que possam ser utilizados no incremento de programas de melhoramento de soja brasileiros<br>Abstract: Soybean stands out as the most important oilseed in the world, given its nutritional and economic importance. Due to increased acreage and hence productivity, today, Brazil is the largest exporter of soybeans. However, it is observed that the genetic basis of soybean is restricted due to the unavailability of alleles able to cope with biotic and abiotic stresses fully efficiently. Thus, breeding programs aimed at increasing the genetic variability for the development of more productive and adapted cultivars. Studies regarding new sources of germplasm, such as Plant Introductions - PIs, become necessary for the identification of agronomic traits of interest to breeders. Therefore, the present work has as main objective the evaluation of agronomic performance and the genetic diversity of 93 accesses of soybean, belonging to a panel of diversity in order to obtain data that can be used in the growth of Brazilian soybean breeding programs<br>Mestre
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Perrault-Archambault, Mathilde. "Who manages home garden agrobiodiversity? : patterns of species distribution, planting material flow and knowledge transmission along the Corrientes River of the Peruvian Amazon." Thesis, McGill University, 2005. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=83198.
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Agrobiodiversity constitutes an essential resource for traditional rural populations. Home gardens are "hotspots" of agrobiodiversity and important loci of in situ conservation efforts. This study seeks to understand the factors affecting gardeners' choices and to assess the accessibility of planting material in rural communities of the Peruvian Amazon. Household surveys and garden inventories conducted in 15 villages of the Corrientes river (n = 300), and case studies in three of these villages (n = 89), allowed to describe the local and regional patterns of garden agrobiodiversity and the structure of planting material exchange networks. Analyses reveal a strong link between species diversity and both household cultural and socioeconomic characteristics, and village ethnicity and size. Planting material flows primarily through matrilineal bonds, from advice-givers to advice-seekers, from old to young and from rich to poor. Farmers with exceptional species diversity, propensity to give and/or expertise are identified and their role in the conservation of cultivated plants is assessed. Expertise is not found to be as closely related to high species diversity as expected, but knowledge and planting stock dissemination go hand-in-hand.
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Mkhize, Thokozani M. "The detection of cherry leaf-roll nepovirus and the use of molecular markers for germplasm identification in walnuts (Juglans regia L.)." Thesis, Stellenbosch : Stellenbosch University, 2003. http://hdl.handle.net/10019.1/53624.
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Thesis (MSc)--Stellenbosch University, 2003.<br>ENGLISH ABSTRACT: The aim of this study was to combine two common diagnostic tools:
serological kits and genetic fingerprinting to identify cherry leaf-roll nepovirus
(CLRV), and to establish a marker system to characterize walnut germplasm.
The detection of plant viruses is difficult. Restrictions are imposed for
quarantine purposes on the importation of plant material from foreign
countries. Modern techniques such as a PCR based screening method for
CLRV are required to ensure material do not harbour viruses. A primer pair
was designed to amplify a 430 bp non-coding homologous region. For the
choice of primers, consensus sequences were considered and areas where
the sequence data shared 98.5% homology, were chosen. The sensitivity of
this detection method was 100-fold higher when compared to the ELISA. The
PCR fragment was verified by nucleotide sequencing.
AFLP technology was used to identify polymorphic fragments for 6 walnut
cultivars and a rootstock, and SCARs were developed from AFLP specific
bands. The AFLP technique distinguished all the walnut cultivars and the
rootstock. However, conversion of AFLP fragments to SCAR markers for the
development of a simple robust technique for cultivar discrimination, was not
successful. Using 27 AFLP primer combinations, polymorphic fragments as
high as 47.8% were scored. The reason for the lack of efficient conversion
was as the result of the AFLP technique. The SCAR primers were generated
from sequences internal to the AFLP primers but the specificity of the markers
was in the AFLP primers not the internal sequence.
In this study using AFLP, walnut cultivars were found to be closely related.
The AFLP primer pairs used, provided polymorphic fragments. From these
fragments, 7 SCAR markers were developed. It was expected that these
SCARs derived from the AFLP markers would detect slight differences
between cultivars. The Paradox SCAR marker was the only one that could
divide the cultivars into two groups. When Chandler SCAR products were
digested with the restriction enzyme Rsal, the same banding pattern as that of
Paradox SCAR products was observed.<br>AFRIKAANSE OPSOMMING: Die doel van hierdie studie was om twee algemene opsporingstegnieke te
kombineer: serologiese toetsstelle en genetiese vingerafdrukke om cherry
leaf-roll nepovirus (CLRV) te eien en om In merkersisteem te ontwikkel wat
okkerneut kiemplasma kan karakteriseer.
Die opsporing van plant virusse is baie moeilik. As gevolg van kwarantyn
vereistes, word daar beperkinge geplaas word op die invoer van plant
materiaal vanuit die buiteland. Moderne tegnieke soos hierdie een wat op
PKR berus, word benodig om te verseker dat CLRV nie in plantmateriaal
teenwoordig is nie. In Stel inleiers is ontwerp wat In 430 bp nie-koderende
homoloë area amplifiseer. Hiervoor is konsensus volgordes bestudeer en
slegs die volgordes wat 98,5% homologie getoon het, is gekies. In
vergelyking met ELISA was die sensitiwiteit van hierdie deteksie metode 100
maal beter. DNA volgordebepaling is op die resulterende fragment gedoen
om die PKR produk te verifieer.
AFLP tegnologie is gebruik om polimorfiese fraqmente vir 6 okkerneut
kultivars en 'n onderstok te identifiseer en SCARs is uit hierdie fragmente
ontwikkel. Die AFLP tegniek kon tussen al die okkerneut kultivars en die
onderstok onderskei. Die omskakeling van die AFLP fragmente in SCAR
merkers om sodoende In eenvoudige kragtige tegniek vir kultivar
onderskeiding te ontwikkel, was egter nie suksesvol nie. Met die gebruik van
27 AFLP inleier kombinasies, kon polimorfiese fragmente van so hoog as
47.8% verkry word. Die rede hoekom omskakeling onsuksesvol was lê by die aard van die AFLP tegniek. Die SCAR inleiers is ontwikkel uit volyordes
intern tot die AFLP inleiers, maar die spesifisiteit van die merkers het juis in
die AFLP inleiers gelê en nie in die interne volgordes nie.
In hierdie studie, met die gebruik van AFLP, is gevind dat okkerneut kultivars
baie naby verwant is. Die AFLP inleierstelle wat gebruik is, het polimorfiese
fragmente gelewer. Uit hierdie fragmente is 7 SCAR merkers ontwikkel. Daar
is verwag dat die SCARs wat uit die AFLP merkers ontwikkel is, klein verskille
tussen kultivars sou opspoor. Dit was egter net die Paradox SCAR merker
wat die kultivars in twee groepe kon verdeel. Restriksie ensiem vertering met
Rsalop die Chandler SCAR produkte het dieselfde bandpatrone as die van
die Paradox SCAR produkte gelewer.
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Lerch, Natalie Corinna. "Home gardens, cultivated plant diversity, and exchange of planting material in the Pacaya-Samiria National Reserve area, northeastern Peruvian Amazon." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1999. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape8/PQDD_0019/MQ54998.pdf.
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Araújo, Francisco Pinheiro de [UNESP]. "Caracterização da variabilidade morfoagronômica de maracujazeiro (Passiflora cincinnata Mast.) no semi-árido brasileiro." Universidade Estadual Paulista (UNESP), 2007. http://hdl.handle.net/11449/103239.
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araujo_fp_dr_botfca.pdf: 860426 bytes, checksum: e6646af0ab59a2403e60928f75194d0c (MD5)<br>Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)<br>O presente trabalho foi desenvolvido com a finalidade de avaliar a variabilidade morfoagronômica de Passiflora cincinnata Mast., distribuída em diferentes regiões agroecológicas do Nordeste brasileiro. Foram utilizadas 32 características obtidas em experimento conduzido na Embrapa Semi-Árido, em Petrolina-PE, em delineamento de blocos ao acaso com quatro repetições. O desempenho dos acessos foi avaliado pela análise univariada e os estudos relativos à divergência genética foram realizados com base nos procedimentos multivariados, utilizando-se a distância generalizada de Mahalanobis (D2) e a técnica de agrupamento por variáveis canônicas. A dispersão gráfica dos acessos teve como eixos as primeiras variáveis canônicas. A estratégia de coleta de acessos de P. cincinnata mostrou-se efetiva porque os acessos coletados apresentaram variabilidade genética para todos os descritores utilizados na avaliação. Os caracteres mais importantes para discriminação entre acessos foram: diâmetro das hastes (DH), número de glândulas foliares (NGF), número de glândulas por bráctea (NGB), viabilidade de pólen (VP), massa do fruto (PF), massa da semente (MS) e massa total de frutos (MTF). Contudo, por serem caracteres influenciados pelo ambiente, os acessos devem ser avaliados em mais de um ambiente. O agrupamento dos acessos com base em suas variabilidades genéticas não foi correlacionado com sua origem geográfica. Foram obtidos acessos que, pela alta produtividade de frutos, podem ser recomendados para cultivos experimentais em áreas de produtores.<br>The present work was developed aiming at evaluating the morphoagronomic variability of Passiflora cincinnata Mast., which is distributed in different agroecological regions in Northeast Brazil. Data from 32 characters were used in experiments, carried out at Embrapa Tropical Semi-Arid, Petrolina-PE, Brazil, in a randomized complete block design with four replications. The behaviour of accesses was evaluated by univariate analysis and the studies related to the genetic diversity were done based on the multivariate procedures, using the general distance of Mahalanobis (Dø) and the grouping technique by canonic variables. The graphic dispersion of the accesses used the first canonic variables as axis. The strategies for collecting the accesses of P. cincinnata proved to be effective because the collected accesses showed genetic variability for all the descriptors used in the evaluation. The most important characters for the discrimination among accesses were: stem diameter (SD), number of leaf glands (NLG), number of glands per bract (NGB), pollen viability (PV), fruit mass (FM), seed mass (SM) and total fruit mass (TFM). However, as the environment influences the characters, the accesses must be evaluated in more than one environment. Grouping of accesses based on their genetic variability was not correlated with their geographic origin. Since some accesses showed high fruit productivity, they can be recommended to farmers for experimental growing.
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Padilha, Henrique Kuhn Massot. "Caracterização morfológica, avaliação agronômica e análise de compostos bioativos em acessos de pimentas (Capsicum annuum)." Universidade Federal de Pelotas, 2014. http://repositorio.ufpel.edu.br:8080/handle/prefix/3077.
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Previous issue date: 2014-02-28<br>Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES<br>Um número muito grande de variedades de pimentas do gênero Capsicum
(Solanaceae) são cultivadas mundialmente, com diferentes formatos e cores.
Os usos destas pimentas são tão diversos quanto os tipos de seus frutos.
Estes são utilizados na alimentação, na medicina, na ornamentação de
ambientes e também como artefato de defesa. Existem cinco espécies
domesticadas de Capsicum: Capsicum annuum, C. baccatum, C. chinense, C.
frutescens e C. pubescens. O objetivo geral deste trabalho foi contribuir para o
conhecimento dos recursos genéticos de acessos de Capsicum annuum que
fazem parte do Banco Ativo de Germoplasma de Capsicum da Embrapa Clima
Temperado. Nesse sentido, foram realizadas atividades de caracterização
morfológica, avaliação agronômica e caracterização química. Foram
submetidos à caracterização morfológica e avaliação agronômica 20 acessos
de C. annuum. Foi verificada ampla variabilidade genética para dias
transcorridos da semeadura ao florescimento, dias transcorridos da semeadura
até a produção do primeiro fruto maduro, estatura da planta, diâmetro médio de
dossel, número de frutos, matéria fresca por frutos, matéria fresca dos frutos
por planta, matéria seca por fruto, relação entre matéria fresca e matéria seca
dos frutos, produção estimada da matéria seca por planta, comprimento do
fruto, diâmetro do fruto, comprimento do pedúnculo e espessura da pare de do
fruto, hábito de crescimento, densidade de ramificação, densidade de folhas,
persistência entre pedúnculo e planta, pungência, aroma, superfície de fruto,
cor de fruto imaturo, cor de fruto maduro, formato de fruto, número de lóculos e
persistência entre fruto e pedúnculo. Para a caracterização química, foi
verificada a produção de compostos bioativos em frutos maduros de 14
acessos de C. annuum. Os acessos avaliados evidenciaram variabilidade
genética para: atividade antioxidante, compostos fenólicos totais, antocianinas
totais e carotenoides totais. Foi possível identificar acessos adequados para
uso em programas de melhoramento com diferentes objetivos, como pimentas
indicadas para consumo in natura e processadas ou pimentas ornamentais.
Para a produção de compostos bioativos os acessos P39, P77, P119, P143 e
P302 demonstraram ser boas fontes de compostos antioxidantes naturais, além
de potencial de uso como planta ornamental. Os resultados obtidos nesse
trabalho são importantes por contribuírem com o conhecimento dos recursos
genéticos de Capsicum e evidenciar de forma clara a relevância da
conservação, caracterização e avaliação de acessos de um Banco Ativo de
Germoplasma.<br>A large number of varieties of Capsicum (Solanaceae) are grown worldwide,
with different shapes and colors. The uses of these peppers are such diverse as
the fruit shapes. These are used in f ood, medicine, ornamentation and also as
an artifact of defense. There are five domesticated species of Capsicum:
Capsicum annuum, C. baccatum, C. chinense, C. frutescens and C. pubescens.
The aim of this study was to contribute to knowledge of genetic resources of
Capsicum annuum accessions from the Embrapa Clima Temperado Genebank
(Pelotas – RS). In this sense, morphologic characterization, agronomic
evaluation and chemical characterization activities were performed. Twenty
accessions of C. annuum were subjected to morphologic characterization and
agronomic evaluation. Wide genetic diversity was observed for days elapsed
from sowing to flowering, days elapsed from sowing to the first ripe fruit
production, plant height, diameter of canopy, number of fruits, fruit weight,
weight fruits per plant, dry matter per fruit, relationship between fresh and dry
matter of fruits, estimated production of dry matter per plant, fruit length, fruit
diameter, peduncle length, wall thickness fruit, growth habit, branching density,
density of leaves, persistence between peduncle and plant, pungency, aroma,
fruit surface, immature fruit color, mature fruit color, fruit shape, number of loci
and persistence between fruit and peduncle. For chemical characterization, was
investigated the production of bioactive compounds in ripe fruits of 14
accessions of C. annuum. The accessions showed genetic diversity for:
antioxidant activity, total phenolic compounds, anthocyanins and carotenoids. It
was possible to identify suitable accession for use in breeding programs with
different objectives, like peppers suitable for fresh consumption and processed
or ornamental peppers. For the production of the bioactive compounds P39,
P77, P119, P143 and P302 accessions demonstrated to be good sources of
natural antioxidants, and potential use as an ornamental plant. The results of
this study are important because they contribute to the knowledge of the genetic
resources of Capsicum and show clearly the importance of conservation,
characterization and evaluation of Active Germplasm Bank accessions.
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Flores, Galdámez Servin Ardany. "Evaluation of forty-two corn (Zea mays L.) genotypes and their tolerance to drought in Chiquimula." BYU ScholarsArchive, 2000. https://scholarsarchive.byu.edu/etd/5362.
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The Corral de Piedra community is located in Chiquimula, Guatemala. The main agricultural activities are corn and bean production, small-scale gardens, and small animal production, such as poultry and pigs. The crop areas are predominantly located on lands with slopes between 12 and 55%, presenting low fertility conditions and poor moisture retention capabilities. In addition, local crop varieties have low productivity potentials and the winter season is characterized by poorly distributed and erratic periods of rain. The Benson Institute introduced a technology transfer model to increase and diversify agricultural production, while preserving current natural resources. An integral part of this model included educating the community on nutrition and health topics. The school was considered to be the most appropriate place to introduce training and education in agriculture among students and community leaders, thus contributing to community development.
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Nguyen, Duc Bach, Van Hai Tong, Van Hung Nguyen, and Huu Ton Phan. "Collection, conservation, exploitation and development of rice genetic resource of Vietnam." Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2015. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-190749.
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Genetic resources are important for the development of every country and for humanity. Collection, conservation and reasonable utilization of genetic resource is required mission. Understanding the importance of genetic resource, especially rice germplasm, since 2001, Center for conservation and development of crop genetic resources (CCD-CGR) of Hanoi University of Agriculture (Vietnam National University of Agriculture) has been collected, conserved and evaluated rice germplasm from different provinces of Vietnam for breeding programs. So far, 1090 accessions of local rice of Vietnam have been collected. Evaluation of agronomic properties and screening of some important genes using DNA molecular markers have revealed that Vietnamese rice germplasm has high level diversity and containing important genes for quality and resistance for disease and pests. These genetic resources are potential materials for national breeding programs. Based on the collected germplasm, 3 new glutinous rice varieties have been successfully created with high yield and good quality. In addition, the degradation of local rice varieties is also a matter of concern. So far, 4 specialty rice varieties Deo Dang, Ble chau, Pu de and Khau dao have been successfully restored for the north provinces of Vietnam. The main results of this study are germplasms for rice breeding programs and new improved varieties that bring economic benefits to farmers and the country<br>Nguồn gene là tài nguyên sống còn của mỗi quốc gia và của toàn nhân loại. Vì vậy thu thập, bảo tồn, đánh giá và khai thác hợp lý nguồn tài nguyên này có ý nghĩa rất lớn. Nhận thức được tầm quan trọng của nguồn gen nhất là nguồn gen cây lúa, ngay từ đầu những năm 2000, Trung tâm bảo tồn và phát triển nguồn gene cây trồng thuộc Trường Đại học nông nghiệp, nay là Học Viện nông nghiệp Việt Nam đã tiến hành thu thập, lưu giữ, đánh giá và khai thác nguồn gene lúa. Kết quả đã thu thập, lưu giữ được 1090 mẫu giống lúa địa phương Việt Nam. Đánh giá đặc điểm nông sinh học và phát hiện một số gene quy định các tính trạng chất lượng và kháng sâu bệnh bằng chỉ thị phân tử DNA. Đây là nguồn gene quan trọng cho chọn tạo giống. Dựa vào nguồn gene thu thập được, cho đến nay, Trung tâm bảo tồn và phát triển nguồn gene cây trồng đã lai và chọn tạo được thành công 03 giống lúa nếp chất lượng cao. Ngoài ra, thoái hóa giống cũng là vấn đề đang được quan tâm. Cho đến nay 4 giống lúa đặc sản Đèo đàng, Ble châu, Pu đe và Khẩu dao đã được phục tráng và đưa vào sản xuất. Kết quả của những nghiên cứu này là ngân hàng các giống lúa làm nguồn gene để chọn tạo giống mới đem lại lợi ích kinh tế cho người nông dân và đất nước
33
Araújo, Francisco Pinheiro de 1957. "Caracterização da variabilidade morfoagronômica de maracujazeiro (Passiflora cincinnata Mast.) no semi-árido brasileiro /." Botucatu : [s.n.], 2007. http://hdl.handle.net/11449/103239.
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Resumo: O presente trabalho foi desenvolvido com a finalidade de avaliar a variabilidade morfoagronômica de Passiflora cincinnata Mast., distribuída em diferentes regiões agroecológicas do Nordeste brasileiro. Foram utilizadas 32 características obtidas em experimento conduzido na Embrapa Semi-Árido, em Petrolina-PE, em delineamento de blocos ao acaso com quatro repetições. O desempenho dos acessos foi avaliado pela análise univariada e os estudos relativos à divergência genética foram realizados com base nos procedimentos multivariados, utilizando-se a distância generalizada de Mahalanobis (D2) e a técnica de agrupamento por variáveis canônicas. A dispersão gráfica dos acessos teve como eixos as primeiras variáveis canônicas. A estratégia de coleta de acessos de P. cincinnata mostrou-se efetiva porque os acessos coletados apresentaram variabilidade genética para todos os descritores utilizados na avaliação. Os caracteres mais importantes para discriminação entre acessos foram: diâmetro das hastes (DH), número de glândulas foliares (NGF), número de glândulas por bráctea (NGB), viabilidade de pólen (VP), massa do fruto (PF), massa da semente (MS) e massa total de frutos (MTF). Contudo, por serem caracteres influenciados pelo ambiente, os acessos devem ser avaliados em mais de um ambiente. O agrupamento dos acessos com base em suas variabilidades genéticas não foi correlacionado com sua origem geográfica. Foram obtidos acessos que, pela alta produtividade de frutos, podem ser recomendados para cultivos experimentais em áreas de produtores.<br>Abstract: The present work was developed aiming at evaluating the morphoagronomic variability of Passiflora cincinnata Mast., which is distributed in different agroecological regions in Northeast Brazil. Data from 32 characters were used in experiments, carried out at Embrapa Tropical Semi-Arid, Petrolina-PE, Brazil, in a randomized complete block design with four replications. The behaviour of accesses was evaluated by univariate analysis and the studies related to the genetic diversity were done based on the multivariate procedures, using the general distance of Mahalanobis (Dø) and the grouping technique by canonic variables. The graphic dispersion of the accesses used the first canonic variables as axis. The strategies for collecting the accesses of P. cincinnata proved to be effective because the collected accesses showed genetic variability for all the descriptors used in the evaluation. The most important characters for the discrimination among accesses were: stem diameter (SD), number of leaf glands (NLG), number of glands per bract (NGB), pollen viability (PV), fruit mass (FM), seed mass (SM) and total fruit mass (TFM). However, as the environment influences the characters, the accesses must be evaluated in more than one environment. Grouping of accesses based on their genetic variability was not correlated with their geographic origin. Since some accesses showed high fruit productivity, they can be recommended to farmers for experimental growing.<br>Orientador: Norberto da Silva<br>Coorientador: Manoel Abilio de Queiróz<br>Banca: Rumy Goto<br>Banca: João Domingos Rodrigues<br>Banca: Grécia Cavalcanti da Silva<br>Banca: Natoniel Franklin de Melo<br>Doutor
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De, Lucchi Chiara. "Improving key root traits in sugar beet: Fusarium resistance." Doctoral thesis, Università degli studi di Padova, 2016. http://hdl.handle.net/11577/3424410.
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The challenge of the twenty-first century is to produce enough food to meet population demands without extending land or damaging the environment. Combining a maximum number of desirable traits such disease resistance, greater yield, and high quality is a desirable goal for plant breeders. The development of resistant crop genotypes is essential to ensure global food security, make the plant more useful and avoid crop losses. The development of molecular markers linked to the target traits is needed to predict phenotypic variation based on genotype. Marker-Assisted Selection (MAS) can reduce costs and the time required to obtain new cultivars by comparing selection only based on phenotypic evaluation. Single nucleotide polymorphisms (SNPs) are widely used as genetic marker.
Sugar beet (Beta vulgaris L.) is the second source of world sugar supply and is grown in all temperate zones. The crop is attacked by many pathogens and among these, the soil-borne fungus Fusarium oxysporum causes severe sugar beet damages. Two different formae speciales have been reported in sugar beet, F. oxysporum f. sp. betae that causes Fusarium yellows, and F. oxysporum f. sp. radicis-betae that causes Fusarium root rot. Disease symptoms are characterized by wilt and yellow leaves that normally die as the disease progresses. Internal symptoms consist of a brown or grey brown vascular discoloration and in the case of root rot, there is a back external rot in the primary root. Sugar beet varieties are susceptible to F. oxysporum, which can cause a lower root yield and reduce sugar quality. No genetic studies have been done up to now, so no genes or quantitative trait loci (QTLs) conferring resistance to F. oxysporum in sugar beet have been reported. The aims of this work were (i) to investigate the response of a wide collection of sugar beet lines to F. oxysporum f. sp. betae, (ii) to identify resistant lines suitable for future breeding efforts and (iii) to discover molecular markers linked to the Fusarium resistance that could be considered for use in marker-assisted selection (MAS) programs.
The first part of the thesis is a literature review of sugar beet breeding achievements, including the discovery of monogermity and cytoplasmic-genetic male sterility (CMS) that allowed the release of hybrid varieties. The review also focused on the breeding progresses against diseases obtained with classical and molecular methods using sources of resistance from wild beets. Next-generation sequencing (NGS) technologies with the recent release of the full sugar beet genome sequence are also reported. Incorporation of genomics into conventional sugar beet breeding programs is essential to obtain important yield achievements in sugar beet.
The second part was aimed at screening a wide range of sugar beet lines to identify the different effect to F. oxysporum f. sp. betae inoculation and to select resistant and susceptible lines. To achieve this, 29 sugar beet lines were screened under greenhouse conditions with two highly virulent isolates belonging to different genetic sub-groups.
The third part regards an experiment conducted to evaluate the response of different sugar beet breeding germplasm to isolates of F. oxysporum f. sp. betae. In the previously tested lines, an unusual root rot was observed, normally reported in cases of infection with F. oxysporum f. sp. radicis-betae. Eight susceptible lines, from USDA-ARS (US) and UNIPD (University of Padova, Italy), were inoculated with three different isolates of F. oxysporum f. sp. betae, the causal agent of Fusarium yellows. All inoculated lines developed disease symptoms, but severe root rot was observed only in the susceptible UNIPD lines inoculated with isolates that had never caused root rot in the USDA germplasm. In this work, an unusual root rot was reported for the first time that seems to be caused not only by the isolates, but is also due to a germplasm effect.
The fourth part was aimed to identify molecular SNP markers linked to the Fusarium resistance in sugar beet. A candidate gene approach was used on susceptible and resistant lines to achieve this goal. Five resistant gene analogues were screened by means of a high-resolution melting (HRM) analysis and two allelic variants, within two genes, were significantly associated to Fusarium resistance. Sanger sequencing allowed the discovery of two SNP markers linked to the resistance. These two SNPs were significantly associated with the resistance and were mapped on the exon of Bv7_171470_ojty and Bv2_043450_zhxk, respectively.<br>Il miglioramento genetico delle piante coltivate, basato sull’esplorazione, sull’utilizzo delle risorse genetiche e sulla ricerca genomica avanzata, è prioritario per soddisfare il fabbisogno alimentare di una popolazione mondiale in costante crescita. In particolare, l’introgressione di tratti desiderabili come la resistenza alle malattie e la maggior resa produttiva è fondamentale per garantire la sicurezza alimentare a livello globale. Per accelerare il miglioramento delle piante è essenziale predire le variazioni fenotipiche sviluppando marcatori molecolari legati ai tratti in esame. La selezione assistita da marcatori molecolari può ridurre costi e tempi di ottenimento di nuove varietà rispetto alla selezione basata solo su variazioni fenotipiche. Fra i marcatori molecolari disponibili, le mutazioni di singola base (SNP) sono i più diffusi.
La barbabietola da zucchero (Beta vulgaris L.) è la seconda fonte di zucchero al mondo ed è coltivata in tutte le aree temperate. La coltura è colpita da numerosi patogeni e, fra questi, il fungo Fusarium oxysporum causa severi danni. Due differenti forme speciali di Fusarium, Fusarium oxysporum f. sp. betae (Fusarium yellows) e Fusarium oxysporum f. sp. radicis-betae (Fusarium root rot) sono state identificate in barbabietola. La malattia è caratterizzata da avvizzimento e clorosi fogliare con un progressivo deperimento delle foglie, spesso seguito dalla morte dell’intera pianta. I sintomi interni consistono in una discolorazione vascolare con imbrunimento dei fasci vascolari e, nel caso di marciume radicale, è presente un caratteristico annerimento all’esterno della radice principale.
Per il controllo del patogeno, l’impiego di fungicidi e le rotazioni colturali non sono efficaci. L’introgressione di geni di resistenza dal germoplasma selvatico è ritenuta la strategia principale per la difesa della coltura. Questo richiede lo sviluppo di marcatori molecolari legati ai geni di resistenza per la selezione assistita degli individui resistenti.
Gli obiettivi del lavoro di tesi sono stati i seguenti: (i) valutare la risposta a Fusarium oxysporum f. sp. betae di un’ampia collezione di linee di barbabietola da zucchero (ii) identificare linee resistenti a Fusarium oxysporum da poter utilizzare in futuri programmi di miglioramento genetico e (iii) identificare marcatori molecolari SNP (polimorfismi del DNA a singolo nucleotide) legati alla resistenza a Fusarium da utilizzare in programmi di selezione assistita da marcatori.
Il primo contributo del lavoro di tesi descrive lo stato dell’arte dei risultati ottenuti nel miglioramento genetico della barbabietola da zucchero. Il contributo si focalizza sui progressi ottenuti nella resistenza a malattie con metodi di miglioramento genetici classico e con l’impiego di tecniche molecolari utilizzando come fonte di resistenza germoplasma selvatico. E’ stato inoltre considerato il contributo delle nuove tecnologie di sequenziamento e del recente rilascio del genoma di riferimento al miglioramento genetico della barbabietola.
Il secondo contributo riguarda la valutazione della risposta a Fusarium oxysporum f. sp. betae di un’ampia collezione di linee di barbabietola da zucchero al fine di identificare linee resistenti e suscettibili. Per raggiungere questo scopo sono state esaminate 29 linee di barbabietola da zucchero. Le piante sono state infettate con due isolati fungini F19 e Fob220a, appartenenti a due gruppi genetici distinti, entrambi altamente patogenici. Dopo l’inoculo, per un periodo di sei settimane, è stato attribuito, per ciascuna pianta, un punteggio da 0 a 5 in base ai vari sintomi di malattia manifestati, quali: avvizzimento fogliare, clorosi e necrosi. Successivamente, le piante sono state raccolte e le radici sono state esaminate per vedere dove era presente marciume radicale, discolorazione e quali piante invece risultavano resistenti al patogeno.
Il terzo contributo descrive la risposta di due diverse collezioni di germoplasma di barbabietola da zucchero a isolati di Fusarium oxysporum f. sp. betae. Linee suscettibili, provenienti da USDA-ARS (US) e UNIPD (Università di Padova, Italia), sono state inoculate con tre distinti isolati di Fusarium oxysporum f. sp. betae, l’agente causa di Fusarium yellows. Tutte le linee inoculate hanno sviluppato i sintomi della malattia, ma un grave marciume radicale è stato osservato solo nelle linee provenienti da UNIPD inoculate con isolati che non avevano mai causato marciume radicale nel germoplasma USDA.
Il quarto contributo riguarda l’identificazione, su geni candidati, di marcatori molecolari SNPs associati alla resistenza alla malattia. In particolare, sono stati identificati 5 analoghi a geni di resistenza (RGA) dal lavoro di Dohm et al. 2014 e sono stati analizzati tramite analisi High Resolution Melting (HRM) su 96 campioni delle 6 linee più resistenti e più suscettibili a Fusarium. Due varianti, in 2 dei geni testati, sono risultate significativamente associate (p < 0.01) con la resistenza a Fusarium. Le varianti sono state validate attraverso sequenziamento Sanger. Il sequenziamento ha permesso di individuare due marcatori SNPs. L’associazione tra questi due SNPs e la resistenza a Fusarium è stata successivamente validata con il metodo di genotipizzazione Comparative allele-specific PCR (KASPar) su 96 campioni resistenti e 96 campioni suscettibili. La frequenza dell’allele A sia per lo SNP_Bv7_171470 e lo SNP_Bv2_043450 è risultata significativamente più alta negli individui resistenti rispetto a quelli suscettibili. Questi due SNPs potranno essere utilizzati in programmi di selezione genetica al fine di migliorare la resistenza a Fusarium in barbabietola da zucchero.
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Dantas, Ana Carolina de Assis. "Caracterização morfológica e molecular de acessos de melão coletados no nordeste brasileiro." Universidade Federal Rural do Semi-Árido, 2011. http://bdtd.ufersa.edu.br:80/tede/handle/tede/142.
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Previous issue date: 2011-02-25<br>Coordenação de Aperfeiçoamento de Pessoal de Nível Superior<br>The melon plant is distributed worldwide and is the kind that has the highest phenotypic variability of the genus, especially observed in its fruit. There is great variability which consists an important source of germplasm for genetic improvement programs. Therefore, the knowledge of the genetic variability of vegetable species and how it distributes itself, provides the rational and sustainable use of genetic resources. The objective of the present study was to do a morphological and molecular characterization of accessions of melon plant collected in brazilian northeastern. Were evaluated 40 accesses and three commercial cultivars in a trial conducted in randomized complete block with two repetitions in Mossoró-RN. The morphological characterization was performed through 17 descriptors, one of the seed, fourteen of fruit and two of the inflorescence. The molecular characterization was performed by RAPD markers using 18 primers and by microsatellite (SSR) with 15 primers synthesized for Cucumis melo. It was verified that the morphological markers, RAPD and SSR were satisfactory to allow the detection of polymorphism among the genotypes evaluated. The grouping methods of Tocher and the hierarchical partially agreed on morphological and molecular characterizations. The RAPD marker was more discriminating in relation to microsatellite by the fact of cluster the accesses in most groups. The germplasm bank of UFERSA has high genetic variability among the accessions.<br>O meloeiro está distribuído em todo o mundo, e é a espécie que possui a maior variabilidade fenotípica do gênero, observada principalmente nos seus frutos. Existe grande variabilidade que consiste em importante fonte de germoplasma para programas de melhoramento. Portanto, o conhecimento da variabilidade genética de espécies vegetais e como ela se distribui, proporciona o uso racional e sustentável dos recursos genéticos. O objetivo do presente trabalho foi realizar a caracterização morfológica e molecular de acessos de meloeiro coletados no Nordeste brasileiro. Foram avaliados 40 acessos e três cultivares comerciais em um experimento conduzido em blocos completos casualizados com duas repetições no município de Mossoró-RN. A caracterização morfológica foi feita através de 17 descritores, sendo um da semente, quatorze de frutos e dois da inflorescência. A caracterização molecular foi realizada pelos marcadores RAPD utilizando 18 primers e por microssatélites (SSR) com 15 primers sintetizados para Cucumis melo. Verificou-se que os marcadores morfológicos, RAPD e SSR foram satisfatórios em permitir a detecção de polimorfismo entre os genótipos avaliados. Os métodos de agrupamento de Tocher e o hierárquico concordaram parcialmente nas caracterizações morfológicas e moleculares. O marcador RAPD foi mais discriminante em relação ao microssatélite pelo fato de agrupar os acessos em mais grupos. O banco de germoplasma da UFERSA possui alta variabilidade genética entre os acessos.
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Du, Min. "A greenhouse screening method for resistance to gray leaf spot in maize." Thesis, Virginia Tech, 1993. http://hdl.handle.net/10919/42953.
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Nguyen, Duc Bach, Van Hai Tong, Van Hung Nguyen, and Huu Ton Phan. "Collection, conservation, exploitation and development of rice genetic resource of Vietnam: Short communication." Technische Universität Dresden, 2014. https://tud.qucosa.de/id/qucosa%3A29104.
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Genetic resources are important for the development of every country and for humanity. Collection, conservation and reasonable utilization of genetic resource is required mission. Understanding the importance of genetic resource, especially rice germplasm, since 2001, Center for conservation and development of crop genetic resources (CCD-CGR) of Hanoi University of Agriculture (Vietnam National University of Agriculture) has been collected, conserved and evaluated rice germplasm from different provinces of Vietnam for breeding programs. So far, 1090 accessions of local rice of Vietnam have been collected. Evaluation of agronomic properties and screening of some important genes using DNA molecular markers have revealed that Vietnamese rice germplasm has high level diversity and containing important genes for quality and resistance for disease and pests. These genetic resources are potential materials for national breeding programs. Based on the collected germplasm, 3 new glutinous rice varieties have been successfully created with high yield and good quality. In addition, the degradation of local rice varieties is also a matter of concern. So far, 4 specialty rice varieties Deo Dang, Ble chau, Pu de and Khau dao have been successfully restored for the north provinces of Vietnam. The main results of this study are germplasms for rice breeding programs and new improved varieties that bring economic benefits to farmers and the country.<br>Nguồn gene là tài nguyên sống còn của mỗi quốc gia và của toàn nhân loại. Vì vậy thu thập, bảo tồn, đánh giá và khai thác hợp lý nguồn tài nguyên này có ý nghĩa rất lớn. Nhận thức được tầm quan trọng của nguồn gen nhất là nguồn gen cây lúa, ngay từ đầu những năm 2000, Trung tâm bảo tồn và phát triển nguồn gene cây trồng thuộc Trường Đại học nông nghiệp, nay là Học Viện nông nghiệp Việt Nam đã tiến hành thu thập, lưu giữ, đánh giá và khai thác nguồn gene lúa. Kết quả đã thu thập, lưu giữ được 1090 mẫu giống lúa địa phương Việt Nam. Đánh giá đặc điểm nông sinh học và phát hiện một số gene quy định các tính trạng chất lượng và kháng sâu bệnh bằng chỉ thị phân tử DNA. Đây là nguồn gene quan trọng cho chọn tạo giống. Dựa vào nguồn gene thu thập được, cho đến nay, Trung tâm bảo tồn và phát triển nguồn gene cây trồng đã lai và chọn tạo được thành công 03 giống lúa nếp chất lượng cao. Ngoài ra, thoái hóa giống cũng là vấn đề đang được quan tâm. Cho đến nay 4 giống lúa đặc sản Đèo đàng, Ble châu, Pu đe và Khẩu dao đã được phục tráng và đưa vào sản xuất. Kết quả của những nghiên cứu này là ngân hàng các giống lúa làm nguồn gene để chọn tạo giống mới đem lại lợi ích kinh tế cho người nông dân và đất nước.
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Bailekae, Masenya Matshidiso. "Development of cryopreservation strategies for improved reproductive competence in South Africa pig genotypes." Thesis, [Bloemfontein?] : Central University of Technology, Free State, 2012. http://hdl.handle.net/11462/145.
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Thesis (M. Tech. Agriculture) -- Central University of Technology, Free state, 2012<br>Frozen-thawed boar sperm has the potential to impact the future of the swine industry. The objectives of the study were to characterise semen of Kolbroek and Large White boars, find a suitable holding temperature and extender, determine the effect of breed and pregnancy rate following artificial insemination by frozen-thawed boar semen. A total of eight boars and 33 sows were used in this study. The 120 ejaculates were collected from each individual Kolbroek and Large White boars with the gloved-hand technique. Macroscopic and microscopic sperm characteristics were recorded. The bodyweight of Kolbroek (154.7 kg) was significantly lower compared to Large White (189.9 kg) boar. However, no significant differences were observed in Kolbroek and Large White boar semen volume (140 and 170 ml), sperm concentration (0.727 and 0.761 x 109 sperm/ml), and total sperm motility (95 and 91%). A positive correlation existed between bodyweight and semen volume of Kolbroek (r= 0.22) and Large White (r= 0.26). Conversely, the bodyweight of Large White was positively correlated to sperm concentration of Large White (r= 0.37) but negatively correlated to Kolbroek (r= -0.66). Storage time and temperature did not affect Large White boar sperm motility rate. However, Kolbroek sperm total motility rate (61.0%) was affected at 25°C after 24 hours. The highest total sperm motility rate was observed for semen diluted with Tris-based extender (74.1%) in Kolbroek boars at 48 hours of storage. Large White boar semen diluted with BTS (62.9%), Kobidil+ (69.3%) and Tris (65.1%) showed significantly higher sperm motility rate at 48 hours of storage, compared to Citrate (27.6%) extender. Cryopreservation significantly reduced sperm motility rate for Kolbroek (30.2%) and Large White (24.0%) boars. However, a high pregnancy rate was recorded in both sows of inseminated with raw diluted (100% vs. 81.3%) and frozen-thawed (50% vs. 50%) semen of Kolbroek and Large White boars. In conclusion, the bodyweight of Kolbroek and Large White boar was positively correlated with ejaculated semen volume. Kolbroek and Large White boar sperm stored at 18°C for 24 hours maintained the acceptable sperm motility rate. Kolbroek boar semen diluted with Tris-based extender maintained high sperm motility rate. Cryopreservation significantly reduced sperm motility rate regardless of breed; however, pregnancy rate from frozen-thawed semen was high for Kolbroek (50%) and Large White (50%) even though the frozen-thawed fertility was low.
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Vieira, Sylvia Dantas. "Caracterização molecular do banco ativo de germoplasma de bromélias." Pós-Graduação em Agroecossistemas, 2013. https://ri.ufs.br/handle/riufs/6574.
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The bromeliad family comprises about 3,000 species distributed in 58 genera and 3 subfamilies: Pitcarnioideae, Bromelioideae and Tillandsioideae. The increasing demand of the market has been responsible for increasing the production and sale of bromeliads. However the illegal extraction is still dramatically reducing existing species. This fact, coupled with the devastation of Brazilian ecosystems, has caused irreparable losses in diversity. Considering this fact, have a basis with stored genetic material for future studies is very important. The main reason for the establishment and maintenance of a germplasm bank is to store and make available germplasm and provide information regarding certain accessions. The aim of the work was to perform the molecular characterization of accessions of native bromeliads prospected in Sergipe State, using tools such as RAPD and ISSR molecular markers and flow cytometry. The collections were performed in four counties of the Sergipe state (Itabaiana, Frei Paulo, Simão Dias e Poço Redondo), whose locations were mapped with the use of a GPS and the individuals were kept in a greenhouse, composing a Active Germplasm Bank (AGB). For molecular analyzes young leaves were collected and used for DNA extraction. Eleven ISSR primers and 13 RAPD primers were used to characterize the prospected accessions. Analyses by flow cytometry were performed for the determination of DNA content, using young leaves and extraction of nuclei was performed following the method of Dolezel. ISSR and RAPD markers detected large genetic variability among the accessions of the AGB. The estimation of the DNA content obtained by flow cytometry of the bromeliad accessions collected in four municipalities of Sergipe State allowed the distinction of two groups (group 1 = 1,59 pg and group 2 = 1,057 pg).<br>A família bromeliácea compreende aproximadamente 3.000 especies, distribuídas em 58 gêneros e 3 subfamílias: Pitcarnioideae, Bromelioideae e Tillandsioideae. A crescente demanda de mercado tem sido responsável pelo aumento da produção e comercialização das bromélias. No entanto o extrativismo ilegal ainda existente está reduzindo drasticamente as espécies. Esse fato, somado à devastação dos ecossistemas brasileiros, tem causado perdas irreparáveis na diversidade. Diante desse fato, ter uma base com material genético guardado para futuros estudos é muito importante. A principal razão para o estabelecimento e a manutenção de um banco de germoplasma é armazenar e disponibilizar germoplasma e prover informações a respeito de determinado acesso. O objetivo do trabalho foi realizar a caracterização molecular dos acessos de bromélias nativas prospectadas no Estado de Sergipe, empregando ferramentas como marcadores moleculares RAPD, ISSR e citometria de fluxo. As coletas foram realizadas em quatro municípios do Estado de Sergipe (Itabaiana, Frei Paulo, Simão Dias e Poço Redondo), cujos locais foram mapeados com o auxílio de GPS e os indivíduos foram conservados em casa de vegetação, compondo um Banco Ativo de Germoplasma (BAG). Para as análises moleculares folhas jovens foram coletadas e utilizadas para a extração do DNA. Onze iniciadores ISSR e 13 iniciadores RAPD foram utilizados para a caracterização dos acessos prospectados. As análises por citometria de fluxo foram realizadas para a determinação do conteúdo de DNA, usando folhas jovens e as extrações dos núcleos foram realizadas seguindo o método de Dolezel. Os marcadores ISSR e RAPD detectaram ampla variabilidade genética entre os acessos do BAG. A estimativa do conteúdo de DNA obtido pela citometria de fluxo dos acessos de bromélias coletados nos quatro municípios de Sergipe possibilitou a distinção de dois grupos (grupo 1 = 1,59 pg e grupo 2 = 1,057 pg).
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Vasconcelos, Carla Sigales de. "Avaliação agronômica e caracterização da produção de compostos bioativos em variedades crioulas de pimentas (Capsicum baccatum)." Universidade Federal de Pelotas, 2012. http://repositorio.ufpel.edu.br/handle/ri/2067.
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Previous issue date: 2012-11-30<br>Genetic resources are essential for sustainable development of agriculture and agribusiness. Landraces, improved varieties, advanced lines and native and wild species are comprised in the concept of genetic resources. The diversity found in Capsicum is wide, with a variety of fruit shapes, sizes, colors and flavors, and also with different levels of pungency and nutritional composition. In this context, this study aims to contribute to the genetic resources knowledge of C. baccatum landraces from collection of Active Germplasm Bank of Embrapa Temperate Agriculture. Two papers will be presented with the objectives of characterize and agronomical evaluate C. baccatum landraces, and characterize the genetic variability to produce bioactive compounds in the fruits. 18 accessions of landraces were evaluated using 27 descriptors (14 quantitative and 13 qualitative multicategoric). The statistical analyzes included comparison of means, using clustering by Tocher method for quantitative data, and clustering by Tocher method and UPGMA for qualitative data. Accessions P27 and P179 are recommended for fresh consumption. The access P92 has the highest productivity and pungent fruits that can be used for canning. Access P8 may be recommended for ornamental use due to prostrate growth habit, high density leaves and erect fruit that change color during maturation. The production of phenolic compounds, anthocyanins, total carotenoids and
antioxidant activity was evaluated at four points of fruit maturation (0%, 30%, 70% and 100%). The data were subjected to multivariate statistical analysis with principal components analysis. The production of bioactive compounds varied according the different points of maturation. Generally the fully ripe fruit produced higher levels of bioactive compounds. Accession P25 had higher values of anthocyanins for fruits with 30% of maturation, which are violet. Accession P108 showed large variations in antioxidant activity, ranging from 588.44 mg in the unripe fruit to 1373.44 mg in 70% of maturation. To carotenoids the accession P49 varied from 65.03 mg in totally immature fruit to 367.73 mg in 100% maturation. There is great genetic variability in C. baccatum landraces.<br>Os recursos genéticos são imprescindíveis para o desenvolvimento sustentável da agricultura e da agroindústria. Compreendem as variedades tradicionais, variedades melhoradas, linhas avançadas e espécies nativas e silvestres. A diversidade encontrada em Capsicum é ampla, com grande variedade de formatos, tamanhos, cores e sabores de fruto, e com diferentes níveis de pungência e de composição nutricional. Esta dissertação se propõe contribuir para o conhecimento dos recursos genéticos de variedades crioulas de Capsicum baccatum que fazem parte do acervo do Banco Ativo de Germoplasma de Capsicum da Embrapa Clima Temperado. Os dados serão apresentados em dois artigos, cujos objetivos são caracterizar e avaliar agronomicamente variedades crioulas de Capsicum baccatum; e caracterizar a variabilidade genética para produção de compostos bioativos em frutos de variedades crioulas de pimenta. Foram avaliados 18 acessos de variedades crioulas, utilizando 27 descritores (14 quantitativos e 13 qualitativos multicategóricos). Foram realizadas análises de comparação de médias, utilizando-se agrupamento pelo método de Tocher, para os dados quantitativos, e agrupamento pelo método de Tocher e de UPGMA, para os dados qualitativos. Os acessos P27 e P179 são recomendados para consumo in natura. O acesso P92 apresenta maior produtividade, com frutos pungentes que podem ser usados para a produção de conservas. O acesso P8 é recomendado para uso ornamental, devido ao hábito de crescimento prostrado, alta densidade de folhas e frutos eretos que passam por quatro cores durante o
processo de maturação. A produção de compostos fenólicos, antocianinas totais, atividade antioxidante e carotenoides totais foi avaliada em quatro pontos de maturação dos frutos (0% de maturação, 30% de maturação, 70% de maturação e 100% maduros). Os dados obtidos foram submetidos à análise estatística multivariada, com análise de componentes principais. A produção de compostos bioativos variou com os diferentes pontos de maturação. De modo geral os frutos totalmente maduros produziram maiores teores de compostos bioativos. O acesso P25 apresentou valores de antocianinas bastante superiores para frutos com 30% maturação, os quais apresentaram coloração violeta. O acesso P108 apresentou grande variação para atividade antioxidante, variando de 588,44 μg nos frutos imaturos a 1373,44 μg nos frutos com 70% de maturação. Para carotenoides o acesso que mais variou foi P49, com 65,03mg em frutos totalmente imaturos e 367,73mg com 100% de maturação. Existe grande variabilidade genética nos acessos de variedades crioulas de Capsicum baccatum.
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Callegaro, Iara do Carmo. "As culturas alimentares tradicionais e seu papel na manutenção da biodiversidade, da segurança alimentar e do patrimônio cultural e genético no território de identidade de Itapetinga-BA, Brasil." Doctoral thesis, Universitat de Barcelona, 2013. http://hdl.handle.net/10803/129454.
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Este estudo se justifica pela necessidade de resgatar a importância da diversidade alimentar e das culturas nativas para a manutenção da biodiversidade e agro biodiversidade, da identidade dos lugares, bem como da garantia da segurança alimentar das comunidades. Objetiva avaliar as espécies vegetais alimentares que já foram cultivadas e consumidas no Território de Itapetinga, avaliando a importância das mesmas na manutenção da diversidade cultural e genética local. A hipótese inicial é de que apesar da redução dos hábitos alimentares a um número reduzido de cultivos, que atualmente constituem a maior parte da dieta humana, o Território de Identidade de Itapetinga ainda mantém, de forma subliminar, parte do seu patrimônio imaterial alimentar e genético. Constitui um estudo qualitativo e teve como instrumentos metodológicos: o questionário, a entrevista estruturada, a observação simples, o registro fotográfico e o diário de campo. O universo de análise desta pesquisa é o Território de Identidade de Itapetinga, constituído de treze municípios da região Sudoeste da Bahia, dos quais foram visitados nove deles para registrar visualmente os produtos comercializados e a presença de agricultores (as), nestas feiras. Foram visitadas casa de farinha, onde se registrou o processamento da mandioca e elaboração de beijus em Itarantim e Itapetinga. A hipótese confirmou-se considerando que a cultura alimentar neste Território tem passado por modificações que acompanham a tendência da globalização alimentar, entretanto há ainda uma diversidade de alimentos associados ao patrimônio imaterial alimentar do Nordeste do Brasil relacionados à afrodecendência e a religiosidade, bem como à manutenção das feiras livres e do setor informal que ainda vive do cultivo, beneficiamento e comercialização de uma diversidade de espécies e produtos, que podem conter as bases para a valorização e o resgate da biodiversidade local.<br>Este estudio se justifica por la necesidad de rescatar la importancia de la diversidad alimentaria y de las culturas nativas para el mantenimiento de la biodiversidad y agro biodiversidad, de la identidad de los sitios, además de la garantía de la seguridad alimentaria de las comunidades. Objetiva evaluar las especies vegetales alimentares que ya han sido cultivadas y consumidas en el Territorio de Itapetinga, evaluando la importancia de las mismas en la manutención de la diversidad cultural y genética local. La hipótesis inicial es de a pesar de la reducción de las costumbres a un reducido número de cultivos, lo que actualmente constituyen la mayor parte de la dieta humana, el Territorio de Identidad de Itapetinga aún mantiene, de manera subliminal, parte de su patrimonio inmaterial alimentario y genético. Constituye un estudio cualitativo y tuvo como instrumentos metodológicos: el cuestionario, la encuesta estructurada, la observancia simple, el registro fotográfico y el diario de campo. El universo de análisis de esta investigación es el Territorio de Identidad de Itapetinga, constituido de trece municipios de la región Suroeste de la provincia de Bahía, Brasil, los cuales han sido visitados nueve de ellos, para registrar visualmente los productos comercializados y la presencia de campesinos(as), en la ferias libres. Han sido visitados aún casas de harina, donde se registró el proceso de la mandioca y elaboración de sus derivados, en Itarantim e Itapetinga. La hipótesis se confirmó considerando que la cultura alimentaria en ese Territorio ha sufrido cambios que acompañan la tendencia de la globalización alimentaria. Sin embargo, hay todavía una diversidad de alimentos asociados al patrimonio inmaterial alimentar del Nordeste de Brasil relacionados con la afro descendencia y la religiosidad, además de la manutención de las ferias libres y del sector informal que aún vive de la transformación y la comercialización de una diversidad de productos que pueden contener las bases para la valorización y el rescate de la biodiversidad local.<br>This study is justified by the need to restore the importance of food diversity and native cultures for the maintenance of the biodiversity and agro- biodiversity, identity of places, as well as to ensure the food security of communities. It aims to evaluate the food plant species that have already been cultivated and consumed in Itapetinga region, assessing their importance in maintaining the cultural diversity and local genetic. The initial hypothesis is that despite the reduction in dietary habits to a small number of crops, which currently constitute the largest part of the human diet, Itapetinga region still retains, subliminally, part of its intangible food and genetic heritage. It is a qualitative study and had as methodological tools: questionnaire, structured interview, simple observation, photographic record and field diary. The universe of analysis of this research is Itapetinga territory, consisting of thirteen counties in the southwestern region in the state of Bahia, Brazil, nine of which were visited, in order to visually record the marketed products and the presence of farmers in the free markets.
We also visited flour mills, where the cassava processing and preparation of its derivatives were registered in Itarantim and Itapetinga. The hypothesis was confirmed considering that the food culture in this territory has undergone changes which follow the food trend of globalization, however, there is still a diversity of foods associated to the intangible heritage food of northeast Brazil related to Afro-Brazilians, religiosity, as well as the maintenance of free markets and the informal sector which still make their living through the processing and marketing of a variety of products that may contain the basis regarding its value and recovering of the local biodiversity.
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Silva, Lidiane Aparecida. "Estratégias de seleção baseada em caracteres químicos e tecnológicos visando a indicação de genitores para produção de bioenergia em cana-de-açúcar." Universidade Federal de Viçosa, 2014. http://locus.ufv.br/handle/123456789/4809.
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Previous issue date: 2014-07-25<br>Coordenação de Aperfeiçoamento de Pessoal de Nível Superior<br>The search for alternative sources of energy, due to the environmental damage caused by greenhouse gases and the depletion of oil easy to extract, resulted in a new phase of growth of the national sugarcane agribusiness. Apart from sugar cane juice to produce sugar and ethanol, the industrialization process obtains the biomass, a lignocellulosic material with high energy content, which can be converted into biofuels. It is essential the characterization of germplasm banks, which consist in great genetic variability and can be used as potential parents in breeding programs. Recognized this importance, the present work aimed to study the genetic diversity of a germplasm bank of cane sugar for selection of potential parents for bioenergy production. Ninety genotypes sown in simple installments and without repetitions were characterized for their chemical and technological constitutions. The descriptive analysis enabled the determination of variability among accessions. The relationships between the variables were estimated from analyzes of simple and partial correlations and the path analysis with the dry matter (MS) as the main variable. To study the genetic divergence, multivariate analyzes were performed. From the Euclidean distance matrix standardized mean, techniques clustering were applied by Tocher optimization method and the hierarchical agglomerative method based on the average linkage between groups (UPGMA). We proceeded with the principal component analysis in order to complement the analysis of clustering. The simultaneous selection of characters, from the index proposed by Mulamba and Mock (1978), allowed the classification of genotypes for different purposes. It was possible to observe amplitude variation high among accessions for all the variables, excepted cellulose. Despite the low correlations for most variables, it was possible to obtain correlated response to selection of the desired characters, highlighting the variable total soluble solids (BRIX), a feature that is easy to measure and can be regarded as the main feature for be used for indirect selection of correlated characters. Path analysis is not the most appropriate to verify the direct and indirect relationships between the variables studied on the main variable (dry matter), because it showed low value of coefficient of determination (R2= 0.29) and high residual effect of the variable (0.84). The clustering methods gathered 90 genotypes, similarly, for eight distinct groups. The principal components , was not satisfactory, since 8 components were needed to explain 83.3% of the variation, however was good to identify the most important for genetic diversity variable was the total sugars (AT) and contributed the least was the dry matter (MS). With the simultaneous selection of characters were ranked ten most promising access for the sugarcane juice quality and the use of bagasse for the production of bioelectricity and/or cellulosic ethanol. From the selected genotypes and the similarity between them, it was possible to indicate potential crosses between parents with high-quality production of sugar and ethanol, as well as an interesting plant biomass for bioenergy production, highlighting 18 crosses between genotypes for bioelectricity, 14 for cellulosic ethanol and 6 for both purposes.<br>A busca por fontes alternativas de energia, devido aos prejuízos ambientais ocasionados pelos gases de efeito estufa e ao esgotamento das reservas de petróleo de fácil extração, resultou numa nova fase de crescimento da agroindústria canavieira nacional. Além do caldo da cana para produção de açúcar e etanol, do processo de industrialização obtém- se a biomassa, um material lignocelulósico, com elevado conteúdo energético, que pode ser convertido em biocombustíveis. É indispensável à caracterização de genótipos de bancos de germoplasmas, que constituem excelente variabilidade genética e podem ser utilizados como genitores potenciais nos programas de melhoramento. Reconhecida esta importância, o presente trabalho teve como objetivo o estudo da diversidade genética de um banco de germoplasma de cana-de-açúcar visando à seleção de genitores potenciais para produção de bioenergia. Noventa genótipos semeados em parcelas simples e sem repetições, foram caracterizados quanto suas constituições químicas e tecnológicas. A estatística descritiva possibilitou a verificação da existência de variabilidade entre os genótipos avaliados. As relações entre os caracteres foram estimadas a partir das análises de correlações simples e parciais e pela análise de trilha que teve como variável principal a matéria seca (MS). Para o estudo da diversidade genética foram realizadas análises multivariadas. A partir da matriz de distância euclidiana média padronizada foi aplicado técnicas de agrupamento pelo método de otimização de Tocher e pelo método aglomerativo hierárquico com base na ligação média entre grupos (UPGMA). Procedeu- se com a análise por componentes principais a fim de complementar as análises de agrupamentos. A seleção simultânea de caracteres, com o índice proposto por Mulamba e Mock (1978), possibilitou selecionar genótipos para diferentes finalidades. Foi possível observar alta amplitude de variação entre os genótipos para os caracteres avaliados, excetuado a celulose. Apesar das baixas correlações encontradas para maior parte das variáveis, foi possível obter resposta correlacionada entre os caracteres desejados para seleção, destacando-se a variável sólidos solúveis totais (BRIX), que é uma característica de fácil medição e pode ser considerada a principal característica para ser utilizada na seleção indireta de caracteres correlacionados. A análise de trilha não é a mais indicada para verificar as relações diretas e indiretas entre os caracteres estudados sobre a variável principal matéria seca (MS), pois apresentou baixo valor de coeficiente de determinação (R2 = 0,29) e alto efeito da variável residual (0,84). Os métodos de agrupamento reuniram os 90 genótipos, de forma similar, em oito grupos distintos. A técnica de componentes principais não foi satisfatória, pois foram necessários 8 componentes para explicar 83,3 % da variação, porém foi eficiente para identificar que a variável mais importante para a diversidade genética foi os açúcares totais (AT) e a que menos contribuiu foi a matéria seca (MS). Com a seleção simultânea de caracteres classificou-se os dez genótipos mais promissores para qualidade do caldo e para aproveitamento do bagaço para produção de bioeletricidade e /ou etanol celulósico. A partir dos genótipos selecionados e da similaridade entre eles, foi possível indicar cruzamentos entre genitores potenciais, com alta qualidade para produção de açúcar e etanol, bem como uma biomassa vegetal interessante para produção de bioenergia, destacando-se 18 cruzamentos para produção de bioeletricidade, 14 para etanol celulósico e 6 para ambas as finalidades.
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Makhathini, Aneliswa Phumzile. "Plant germplasm conservation :|bdevelopment of field collection and transport techniques for eucalyptus species and trichilia dregeana." Thesis, 2002. http://hdl.handle.net/10321/2063.
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Dissertation submitted in compliance with the requirements for the Master's Degree in Technology: Biotechnology, Technikon Natal, 2002.<br>Lack of suitable techniques for field collection of the germplasm of different species, and spoilage of samples in transit, hinder efforts to collect, conserve, distribute and regenerate most plant germplasm in vitro. The aims of this investigation, therefore, were to address problems encountered in collection of field germplasm from species and hybrids of Eucalyptus (TAG5, TAGI4, ZG14, GC550 and GU2IO) that are propagated vegetatively and Trichilia dregeana, which has recalcitrant seeds. Simple in vitro culture-based protocols were developed to minimise contamination and maintain viability of plant material for sufficient time for it to be transported from the field to the tissue culture laboratory. From the two simulations of 48 h 'transportation' conditions for explants of Eucalyptus species investigated, those in bottles containing sterile vermiculite exhibited no contamination and greater than 50% bud break, regardless of whether or not field surface sterilization with alcohol had been done. In contrast, when explants were enclosed in cling wrap, contamination was high and bud break levels low. For selection of the more suitable Eucalyptus explant, two types were investigated: nodal explants each with one half leaf (type 1) and stem segments with three nodes (type 2). As type 2 showed considerably better shoot yields (up to 1624 shoots per 100 explant), and were more practical to use with respect to space, such trinodal stem segments were deemed best for collection. Of the sterilization procedures investigated, treatment with 70% (v/v) alcohol prior to storage was found to be most suitable in almost all cases. For plant material with high endogenous microbial contamination, the bud break medium was supplemented with Benomyl and calcium hypochlorite, each at 0.5 and 1.0 g.r). Alcoholtreated, stored explants cultured on bud break medium with 1.0 g.r) calcium hypochlorite exhibited low levels of contamination and an increased final yield (up to a maximum of 930 shoots per 100 explants). Thus, this protocol was employed for field material of E. grandis clones TAG5, TAGI4 and ZGI4. For these clones, stored type 2 explants<br>M
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Lin, Ting-Yu, and 林庭聿. "The interspecies hybridization of Impatiens genus and germplasm resources preservation." Thesis, 2017. http://ndltd.ncl.edu.tw/handle/61562831333085703430.
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碩士<br>國立中興大學<br>園藝學系所<br>105<br>Impatiens walleriana was the important winter bedding plants in Taiwan. By observing the habitats as well as the characters of perianths and trying to pollinate, We finally picked up I. walleriana as seed parents and I. taymonii as pollen parents, expecting that the hybrides will surive and be attractive.
All three native Impatiens species had the ability to set seeds in Shei-Pa national park and Mai-Feng. The seeds numbers of a capsule in Impatiens devolii was not different in two habitats. Impatiens tayemonii in Shei-Pa national park had more seeds than in Mai-Feng. Impatiens uniflora in Mai-Feng had more seeds than in Shei-Pa national park. Only Impatiens devolii and Impatiens devolii can growth in 20℃ growth chamber, Impatiens uniflora didn`t conduct later experiment of hybridization .
In the hybridization test, the perianth of I. tayemonii and I. devolii consisted with three sepals and three petals. I. walleriana had three sepals and five petals. The stigma of three Impatiens species were surrounded with filments. For I. devolii, during the period of initial flower bloom, the stigma will grow and reach into the anther. However, the stamen of I. tayemonii and I. walleriana will fall off and then pistil mature.The capsules which using Impatiens walleriana ‘Accent’ red or white color to cross with Impatiens tayemonii as well as Impatiens devolii dropped after four to six days . Anatomical observation that the embryo sacs were empty after pollinating eight days. The ovules which pollinated after six days could find global embryo but in these embryo sac had no endosperm.Using different ratio of plant growth regulators to conduct ovary culture, most ovaries swelled. However, the ovules were blacking after culturing three days and most ovules dead after culturing eight days in vitro.
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Matus, Iv��n Ariel. "Exploiting Hordeum vulgare subsp. spontaneum genetic resources : diversity analysis and germplasm development." Thesis, 2002. http://hdl.handle.net/1957/31493.
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Wild barley (Hordeum vulgare subsp. spontaneum) could be a source of useful
genes for improving cultivated barley. The useful genes present in Hordeum
vulgare subsp. spontaneum may be new alleles at described loci, or these may be
entirely new genes in the sense that there is limited allelic variation at these loci in
the cultivated germplasm pool. This research was directed at gene discovery in wild
barley and involved two steps: (i) characterization of diversity using genetic
markers and (ii) development and characterization of novel germplasm for gene
discovery.
Simple Sequence Repeats (SSRs) of known map location were used to survey three
representative groups of barley germplasm: a sample of crop progenitor (Hordeum
vulgare subsp. spontaneum) accessions, a group of mapping population parents,
and a group of varieties and elite breeding lines. The objectives were to determine
the informativeness and utility of SSRs in differentiating and classifying the three
sets of barley germplasm. Crop progenitors had the highest number of alleles per
SSR locus, followed by mapping population parents and elite breeding lines. The
cluster analysis indicated a high level of diversity within the crop progenitor
accessions and within the mapping population parents. It revealed a much lower
level of diversity within the elite breeding germplasm.
A set of Recombinant Chromosome Substitution Lines (RCSLs) representing
introgressions of Hordeum vulgare subsp. spontaneum genome in to a cultivated
barley background were developed using the Advanced Backcross strategy. An
accession of Hordeum vulgare subsp. spontaneum was the donor parent and the
variety "Harrington" was the recurrent parent. The RCSLs were developed via two
backcrosses to the recurrent parent followed by six generations of selfing. The
genomic architecture of the RCSLs was determined by molecular marker
fingerprinting with SSRs. The consequences of introgressions of Hordeum vulgare
subsp. spontaneum genome segments into the recurrent parent were assessed in
terms of inflorescence yield components, malting quality traits, and domestication-related
traits. Hordeum spontaneum subsp. spontaneum, despite its overall inferior
phenotype, contributed favorable alleles for some characters of agronomic
performance. In other cases, the introgressions caused a disruption of the
Harrington phenotype, a "reverse genetics" approach to gene discovery.<br>Graduation date: 2003
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Thangwana, Andries. "The Response of Tepary Bean (Phaseolus actifolius) Germplasm to Induced Mutation." Diss., 2016. http://hdl.handle.net/11602/856.
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Essack, Lubaina. "Towards development of a cryopreservation protocol for germplasm of Podocarpus henkelii." Thesis, 2012. http://hdl.handle.net/10413/8545.
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The trees belonging to the genus Podocarpus, of which only four species are native to South Africa, are renowned for their superior quality timber. Prior to 1880, Podocarpus henkelii, together with P. falcatus and P. latifolius, played a significant role in the development of the country as they were heavily utilised as timber trees for the building of dwellings, furniture and other necessary items. Due to this over-exploitation in the timber trade, all the Podocarpus species in South Africa have been afforded a ‘Protected’ status on the IUCN red data list of species that are either threatened or in danger of extinction. However, despite the obvious need to conserve the threatened genetic diversity of these species, few attempts (aside from in vitro micropropagation) have been made to explore ex situ Podocarpus germplasm conservation in the long-term. Consequently, the primary aim of this study was to establish a protocol for the long-term conservation of germplasm of Podocarpus henkelii Stapf ex Dallim. Jacks.
The seeds of Podocarpus henkelii exhibit recalcitrant behaviour and can therefore not be stored in conventional seed banks. This has necessitated the investigation of alternative methods of germplasm conservation with a focus on cryopreservation which is presently considered the most reliable, efficient and cost-effective means of storing the genetic resources of recalcitrant-seeded species for prolonged periods. The first objective of this study was to investigate the effect of slow (two-step) and ultra-rapid cooling on the post-thaw survival of variously treated P. henkelii embryos. The results of this investigation revealed that the rate of cooling employed had a significant effect on explant viability as none of the precultured, cryoprotected embryos that were slowly cooled survived cryostorage while some of the preconditioned embryos responded to ultra-rapid cooling (i.e. 36% shoot production and 88% callus formation). For ultra-rapid cooling, it was found that flash-drying prior to cooling was a prerequisite for survival as osmotic dehydration alone did not effectively prepare the tissues for the stresses imposed during cryostorage. Furthermore, for those flash drying intervals that yielded positive results, preconditioning explants with 10% glycerol proved the most effective pre-cooling treatment. However, due to the low recovery numbers after ultra-rapid cooling, a third cryopreservation technique i.e. cryogenic vitrification, was investigated.
For cooling by vitrification, data obtained from preliminary experiments showed that precultured explants needed to be initially loaded with 18% sucrose (w/v) + 14% glycerol (v/v) for 20 min and subsequently immersed in Plant Vitrification Solution 3 (PVS3) at 0°C for 10 min prior to cooling. However, relatively low success was achieved for P. henkelii embryos cooled by vitrification as the highest post-cooling survival obtained was only 20% germination, 27% shoot formation and 37% callus formation.
Due to the low post-thaw survival obtained despite the rigorous manipulations employed in the development of the slow cooling, ultra-rapid cooling and vitrification protocols, it was decided that an alternative explant should be investigated for the conservation of P. henkelii germplasm. The explant of choice was adventitious buds induced to form on, and subsequently excised from, mature P. henkelii embryos. The first objective was to develop a suitable protocol for the induction of adventitious buds on P. henkelii embryos. The medium that induced in the highest percentage of embryos (85%) to form adventitious buds consisted of Douglas-fir cotyledon revised (DCR) basal medium supplemented with 30 g L-1 sucrose, 0.05 mg L-1 NAA, 0.5 mg L-1 BA and 6 g L-1 agar. This medium also resulted in the highest average number of buds formed per embryo (i.e. 35 ± 3 buds per embryo). Once the adventitious bud induction medium was developed, it was necessary to optimise the size of adventitious bud clumps to be used as explants for cryopreservation. Three bud clump sizes were investigated: ca 3, 5 and 10 buds per clump. However, none of the bud clumps survived excision from the mother-tissue despite the investigation of three different types of bud-break media. The resultant tissue mortality is suggested to have occurred because the adventitious bud clumps were excised prior to bud break and shoot development which could have exacerbated excision-related cellular and sub-cellular damage.
It was therefore decided that attempts should be made to induce adventitious buds directly on P. henkelii embryos post-cooling, thereby eliminating the possibility of potentially lethal excision-related damage. The protocols that yielded the best results after ultra-rapid cooling and cooling by vitrification were used in this experiment. For ultra-rapid cooling, embryos were first cryoprotected with 5% followed by 10% glycerol for 1 h in each and subsequently flash dried for 30 min prior to immersion in nitrogen slush. For cooling by vitrification, embryos that were first precultured on 0.3
M sucrose for 1 d were loaded with 10% glycerol + 14% sucrose (LS4). The loaded explants were then immersed in ice-cold PVS3 and maintained on ice for 10 min prior to cryostorage. The effect of each pretreatment (either independently or in combination) on adventitious bud production pre-cooling was also investigated. For both protocols the various pretreatments decreased not only the capacity of the embryos to form buds but also the average number of buds formed per embryo (i.e. 7 ± 2 buds per embryo and 14 ± 2 buds per embryo were formed on treated embryos prior to ultra-rapid cooling and cooling by vitrification, respectively). Thus, it was predicted that even if the percentage of cryopreserved embryos forming buds was minimal, the number of possible plantlets that could be regenerated from adventitious buds per cryopreserved explant would compensate for the low recovery of embryos post-cooling. However, none of the embryos that were cryopreserved by either ultra-rapid cooling or by vitrification formed adventitious buds after eight weeks in culture.
The very restricted success achieved in this study despite the investigation of three cryopreservation techniques and two different explants only serves to reinforce the difficulties associated with the conservation of recalcitrant germplasm. The large size and structural complexity of P. henkelii embryos, coupled with their high water content post-shedding, are just some of the characteristics to which their intractability to the manipulations involved in the development of a successful cryopreservation protocol could be attributed. For future investigations, development of adventitious buds produced on cryopreserved root segments (as opposed to entire roots), and/or use of seedling meristems as explants which might be amenable to cryopreservation are suggested as possible avenues for the long-term conservation of P. henkelii genetic diversity.<br>Thesis (M.Sc.)-University of KwaZulu-Natal, Westville, 2012.
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Hodgin, Heather Mariel. "Safeguarding Anthurium genetic resources : in vitro germplasm bank development and flow cytometry analysis." Thesis, 2006. http://hdl.handle.net/10125/20917.
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Rodriguez, Ana Carolina Roa. "Governing property of plant genetic resources in the Andean community : from multiple to multilevel governance." Phd thesis, 2009. http://hdl.handle.net/1885/141213.
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Mvududu, DonTafadzwa Kudzanai. "Screening of cassava improved germplasm for potential resistance against cassava mosaic disease." Thesis, 2017. http://hdl.handle.net/10539/22733.
Full textAbstract:
A dissertation submitted to the Faculty of Science, University of the
Witwatersrand, in fulfillment of the requirements for the degree of Master of
Science in the School of Molecular and Cell Biology.
Johannesburg 2017<br>With growing populations and climate change associated drought predicted for the future, cassava can provide one solution for food security and a source of starch for industrial use and biofuels in South Africa, and other countries in the SADC region. One of the severe constraints on cassava production is cassava mosaic disease (CMD) caused by cassava infecting begomoviruse species, including African cassava mosaic virus (ACMV), South African cassava mosaic virus (SACMV) and East African cassava mosaic virus (EACMV). Cassava begomoviruses (CBVs) are responsible for significant yield loss of the starchy tubers. Since no chemical control of virus diseases of plants is possible, one approach to develop virus resistance is via biotechnology, through genetic engineering (GE) of cassava with hairpin RNA (hpRNA) silencing constructs that express small interfering RNAs targeting CBVs and preventing severe disease development. The aim of this project was to subject previously transformed five CMM6 cassava lines (cv. 60444 transformed with a non-mismatched Africa cassava mosaic virus-[Nigeria:Ogorocco;1990] (ACMV-[NG:Ogo:90])-derived hpRNA construct, six AMM2 (cv. 60444 transformed with a mismatched ACMV-[NG:Ogo:90]-derived hpRNA construct), six CMM8 cassava lines (cv.60444 transformed with a non-mismatched SACMV BC1-derived hpRNA construct) and seven AMM4 cassava lines (cv.604444 transformed with a mismatched SACMV BC1-derived hpRNA construct) to reproducible trials, and evaluate for response to virus challenge. The ACMV-[NG:Ogo:90] hpRNAi constructs target 4 overlapping virus open reading frames (ORFs) (AC1 replication associated protein/AC4 and AC2 transcriptional/AC3 replication enhancer), while the SACMV hpRNAi constructs target the cell-to cell movement BC1 ORF. Non mismatched constructs consist of a transformation cassette that has an intron separating the sense and antisense arms of the viral transgene whilst mismatched constructs have the sense arm of the viral transgene treated with bisulfite to induce base mutation. This mutated sense arm is then separated from the non mutated antisense arm by a small spacer. Furthermore, a 229 bp inverted repeat hpRNA construct (DM-AES) was designed to target ACMV-[NG:Ogo:90] 117 nt putative promoter region (2714-49 nt), a 91 nt overlapping sequence (1530-1620 nt) between ACMV-[NG:Ogo:90] AC1 3’ end and AC2 5’ end (AC1 3’/AC2 5’-ter) as well as being efficient against SACMV and EACMV due to the inclusion of a 21 nt conserved sequence (1970-1990) of AC1/Rep shared between ACMV, EACMV and SACMV. Cassava landrace T200 friable embryogenic callus (FEC) were transformed with this construct. The
selected transgenic lines were infected with either ACMV-[NG:Ogo:90] (CMM6 and AMM2
transgenic lines) or SACMV (CMM8 and AMM4 transgenic lines) by agro-inoculation and
monitored at 14, 36 and 56, 180 and 365 days post infection (dpi) for symptom development,
plant growth and viral load. From the ACMV trials 3 lines (CMM6-2, CMM6-6 and line
AMM2-52) showed significantly lower symptom scores and lower viral load at 36, 56 and
365 dpi, compared with viral challenged untransgenic cv.60444. This phenotype is described
as tolerance, not resistance, as despite ameleriorated symptoms virus replication persists at
lower levels. From the SACMV infectivity trials even though all CMM8 and AMM4
transgenic lines had lower symptom severities and viral loads compared with infected
untransformed cv.60444, the results were not highly significant (p˃ 0.05). From this study,
tolerance or reduction of viral load and symptoms was attributed to the accumulation of
transgene-derived siRNAs prior to infection. However there was no observable correlation
between levels (semi-qauntitative northern blots) of siRNAs and tolerance or susceptible
phenotypes. Tuber yield evaluation of the three tolerant lines (CMM6-2, CMM6-6 and line
AMM2-52) showed that the tuber fresh and dry weight at 365 dpi was not affected by the
viral presence. These are promising lines for larger greenhouse and field trials. A comparison
between the two different constructs showed that the two tolerant CMM6 lines-2 and 6
appeared to perform better (viral load) compared with AMM2 tolerant line-52 with regards to
levels of viral amplification. The mismatched construct in AMM4 lines and the nonmismatched
construct in CMM8 lines induced the same viral and symptom severity score
(sss) reduction. Transformation of T200 FECs with the DM-AES construct was unsuccessful
due to the age (more than six months old) of the FECs. FECs are more likely to lose their
regeneration and totipotent nature with age. We therefore propose the use of fresh T200 FECs
in future transformation studies to test the DM-AES construct.<br>MT2017