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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Accelerated Crop Domestication through Identification of Phenotypic Characteristics of Taraxacum kok-saghyz Relevant to Rubber Yield

McNulty, Sarah Kristine January 2019 (has links)
No description available.
2

Úloha polymorfních markerů DNA v identifikaci osob a určování vybraných fenotypových znaků. / Role of polymorphic DNA markers in personal identification and determination of selected phenotypic traits

Zidkova, Anastassiya January 2013 (has links)
Nowadays intensive research is conducted for application of genetic polymorphisms for degraded samples analysis, identification and kinship determination. Another area of research in forensic genetics is biogeographical and phenotypic traits (eye, hair and skin color) determination. First part of presented work dealt with population study on the Czech popu- lation using Investigator DIPplex (QIAGEN, Germany) marker set containing 30 autosomal insertion-deletion polymorphisms. Power of Discrimination (PD), which is the probability of random selection of two persons with different genotypes, was 99.9999999999% for the whole marker set. This part of study concluded that ana- lyzed marker set is suitable as an additional marker panel for identification and kinship determination in the Czech Republic. Second part of the presented study was devoted to population research of Cen- tral Croatia using Mentype Argus X-8 kit (QIAGEN, Germany) containing 8 short tandem repeat polymorhisms located on X choromosomes (X-STR) divided into 4 linkage groups. PD for the whole kit reached 99.9999% and 99.99999999% for males and females, respectively. This kit could be used in Central Croatian population for kinship analysis and for identification as an additional marker panel. The next part of the presented study was the...
3

Phenotypic and Genetic Characterization of Wildland Collections of Western and Searls Prairie Clovers for Rangeland Revegetation in the Western USA

Bhattarai, Kishor 01 December 2010 (has links)
Western prairie clover [Dalea ornata (Douglas ex Hook.) Eaton & J. Wright] is a perennial legume that occurs in the northern Great Basin, Snake River Basin, and southern Columbia Plateau, whereas Searls prairie clover [Dalea searlsiae (A. Gray) Barneby], also a perennial legume, occurs in the southern Great Basin and surrounding areas. Understanding the genetic and ecotypic variation of these prairie clovers is a prerequisite for developing populations suitable for rangeland revegetation in the western USA. DNA sequences of internal transcribed spacer (ITS/5.8S) and trnK/matK were used to study the phylogeny of these species. The species were distinguished by DNA sequences from both regions and conserved haplotypes were observed between and within species. Common-garden plots of 22 collections of western prairie clover from Idaho, Oregon, and Washington and 20 collections of Searls prairie clover from Utah and Nevada were established in northern Utah for phenotypic evaluation. Significant variation was detected among the collections for all traits measured in the common gardens for both species. Flowering date was correlated with collection-site temperature and elevation in western prairie clover collections, whereas biomass-related traits were closely related with collection-site precipitation in Searls prairie clover. Population structure from amplified fragment length polymorphism (AFLP) markers resulted in two distinct, genetically differentiated groups and a third admixed group in western prairie clover, and flowering date played a significant role in discriminating those genetic-based groupings of collections. For western prairie clover, two populations are recommended for development, one from the Deschutes River watershed and another from the remaining collections. For Searls prairie clover, two genetically different groups of collections were identified from southern Utah and eastern Nevada and from northwestern Utah. Three western Nevada collections exhibited close association with eastern Nevada and southern Utah groups for AFLP-markers but with collections from northwestern Utah for phenotypic traits. Strong isolation by distance was observed for Searls prairie clover collections suggesting that genetic drift and gene flow are major factors for determining population structure in this species. As a result, two regional seed sources should be developed for Searls prairie clover, one from northwestern Utah and the other from eastern Nevada and southern Utah.
4

Introducing Explorer of Taxon Concepts with a case study on spider measurement matrix building

Cui, Hong, Xu, Dongfang, Chong, Steven S., Ramirez, Martin, Rodenhausen, Thomas, Macklin, James A., Ludäscher, Bertram, Morris, Robert A., Soto, Eduardo M., Koch, Nicolás Mongiardino 17 November 2016 (has links)
Background: Taxonomic descriptions are traditionally composed in natural language and published in a format that cannot be directly used by computers. The Exploring Taxon Concepts (ETC) project has been developing a set of web-based software tools that convert morphological descriptions published in telegraphic style to character data that can be reused and repurposed. This paper introduces the first semi-automated pipeline, to our knowledge, that converts morphological descriptions into taxon-character matrices to support systematics and evolutionary biology research. We then demonstrate and evaluate the use of the ETC Input Creation - Text Capture - Matrix Generation pipeline to generate body part measurement matrices from a set of 188 spider morphological descriptions and report the findings. Results: From the given set of spider taxonomic publications, two versions of input (original and normalized) were generated and used by the ETC Text Capture and ETC Matrix Generation tools. The tools produced two corresponding spider body part measurement matrices, and the matrix from the normalized input was found to be much more similar to a gold standard matrix hand-curated by the scientist co-authors. Special conventions utilized in the original descriptions (e.g., the omission of measurement units) were attributed to the lower performance of using the original input. The results show that simple normalization of the description text greatly increased the quality of the machine-generated matrix and reduced edit effort. The machine-generated matrix also helped identify issues in the gold standard matrix. Conclusions: ETC Text Capture and ETC Matrix Generation are low-barrier and effective tools for extracting measurement values from spider taxonomic descriptions and are more effective when the descriptions are self-contained. Special conventions that make the description text less self contained challenge automated extraction of data from biodiversity descriptions and hinder the automated reuse of the published knowledge. The tools will be updated to support new requirements revealed in this case study.
5

Métodos multivariados no estudo da diversidade genética e adaptabilidade e estabilidade em soja convencional

Felici, Paulo Henrique Nardon 22 February 2017 (has links)
O estudo da diversidade genética e o conhecimento das relações entre cultivares melhoradas é fundamental para os programas de melhoramento de soja, pois auxiliam na seleção de genitores e recomendação de cultivares. Esta tese está subdividida em três capítulos, sendo que o primeiro traz o referencial teórico relacionado à cultura, à importância econômica e ao melhoramento da soja. O segundo capítulo, por sua vez, foi desenvolvido com os objetivos de: avaliar a diversidade genética a partir de caracteres fenotípicos de genótipos de soja convencional de ciclo precoce em ambientes distintos; determinar a importância de caracteres na divergência genética de soja; e selecionar genitores de ampla diversidade genética para programa de melhoramento, utilizando diferentes métodos de agrupamento multivariados. O experimento foi conduzido em dois locais distintos, Campo Novo dos Parecis - MT, safra 2010/2011 e Urutaí - GO, safra 2012/2013. Foram avaliados dez genótipos de soja convencional de ciclo precoce, em delineamento de blocos completos casualizados, nos quais foram mensurados oito caracteres agronômicos. Por meio de análises uni e multivariadas, foi possível concluir que os agrupamentos formados por todos os métodos multivariados, aliados às médias dos valores fenotípicos dos genótipos, permitiram inferir sobre as combinações promissoras para hibridações artificiais. Ao considerar os dois ambientes de cultivo, o número de dias para a floração, a altura da planta na maturidade e altura de inserção da primeira vagem foram os caracteres que mais contribuíram para a divergência genética em soja. As linhagens UFU 106 e UFU 108 são as mais recomendadas como parte das hibridações com genótipos divergentes, pois são complementares em produtividade de grãos e menor fase vegetativa. Recomenda-se hibridações entre os seguintes pares de genótipos: UFU 106 x UFU 112; UFU 106 x Emgopa 316; UFU 108 x Emgopa 316; UFU 112 x Emgopa 316, para a obtenção de populações segregantes com variabilidade genética superior. O terceiro capítulo foi elaborado para avaliar a interação genótipos por ambientes para o caráter produtividade de grãos em genótipos de soja convencional, de ciclo precoce. Assim, os genótipos foram cultivados em 15 ambientes, distribuídos em cinco estados brasileiros, para determinar sua adaptabilidade e estabilidade por intermédio de métodos paramétricos, não paramétricos e multivariados. O método Wricke (1965), Eberhart e Russel (1966) e AMMI identificaram as linhagens UFU 21 e UFU 22 como as mais estáveis, sendo que ambas apresentaram produtividade de grãos superior a 3800,00 kg ha-1. A linhagem UFU 06 obteve média de produtividade de grãos superior a 4000,00 kg ha-1 e apresentou adaptação ampla pelos métodos Annicchiarico (1992) e Lin e Binns (1988) modificado por Carneiro (1998) e Centróide. / The study of genetic diversity and the knowledge of the relationships among improved cultivars are fundamental for soybean breeding programs, since they help the selection of breeders and recommendation of cultivars. This thesis is subdivided into three chapters, the first one deals with a theoretical reference regarding the culture, the economic importance and the improvement of soybean. The second chapter was developed with the objective of evaluating the genetic diversity from phenotypic traits, of conventional early maturity soybean genotypes in different environments, determining the importance of traits in soybean genetic divergence and selecting parents of broad genetic diversity for breeding programs, using different multivariate clustering methods. The experiment was conducted in two distinct locations, Campo Novo dos Parecis - MT, season 2010/2011 and Urutaí - GO, season 2012/2013. Ten genotypes of conventional early maturity soybean were evaluated in a randomized complete block design, in which eight agronomic characters were measured. By univariate and multivariate analyzes it was possible to conclude that the groupings formed by all the multivariate methods, with the means of the phenotypic values of the genotypes, allowed to infer about the promising combinations for artificial hybridizations. Number of days for flowering, plant height at maturity and height of insertion of the first pod were the characters that contributed the most to the genetic divergence in soybean when considering the two crop environments. UFU 106 and UFU 108 lines are the most recommended as part of the hybridizations with divergent genotypes, since they are complementary in grain yield and lower vegetative phase. Hybridizations between the following pairs of genotypes are recommended to obtain segregating populations with superior genetic variability: UFU 106 x UFU 112; UFU 106 x Emgopa 316; UFU 108 x Emgopa 316; UFU 112 x Emgopa 316. The third chapter was elaborated to evaluate the genotype interaction by environments for grain yield characteristics in conventional soybean genotypes of early maturity, grown in 15 environments distributed in five Brazilian states, to determine the adaptability and stability of the genotypes by parametric, non-parametric and multivariate methods. Wricke (1965), Eberhart and Russel (1966) and AMMI methods identified UFU 21 and UFU 22 lines as the most stable, both with grain yields higher than 3800,00 kg ha-1. The strain UFU 06 obtained an average grain yield of more than 4000,00 kg ha-1 and presented wide adaptation by Annicchiarico (1992), Lin and Binns (1988) modified by Carneiro (1998) and Centroid methods. / Tese (Doutorado)
6

Quels facteurs limitent l’installation de Brachypodium retusum : une espèces clé pour la restauration écologique des steppes méditerranéennes ? / Which factors limit the etablishement of brachypodium retusum : a key species in ecological restoration of Mediterranean steppes ?

Vidaller, Christel 14 December 2018 (has links)
Le brachypode rameux (Brachypodium retusum) est une espèce herbacée pérenne qui domine les pelouses sèches de Méditerranée occidentale. Dans notre zone d’étude du Sud de la France, la recolonisation spontanée est très faible après perturbation du sol. Cette observation ne correspond pas aux résultats d'études menées dans d'autres régions montrant une capacité de colonisation élevée. L'objectif principal de cette thèse était donc de tester les différentes hypothèses pouvant expliquer les différents patrons de colonisation.Dans un premier chapitre, nous avons testé si ces différents patrons de colonisation résultent d'une différenciation génétique entre les populations. Des marqueurs AFLP ont été utilisés pour analyser la structure génétique de 17 populations de Méditerranée occidentale dont la différenciation neutre entre populations. Dans un sous-échantillon de 13 populations françaises, la différenciation de traits phénotypiques sous sélection a été testée dans un jardin commun et comparée à la différenciation neutre. Dans le deuxième chapitre, nous présentons une étude sur la différenciation adaptative des traits phénotypiques et avons testé une potentielle réponse différentielle à la manipulation de facteurs environnementaux clés. Les deux derniers chapitres de la thèse ont analysé les facteurs environnementaux qui limitent la recolonisation in situ, indépendamment du génotype ou de la population. Dans le troisième chapitre, nous avons testé l’effet du pâturage et du feu sur le recouvrement végétatif ainsi que sur la reproduction sexuée de B. retusum installé. Enfin, dans le quatrième chapitre, nous avons mesuré l’effet de l’arrosage initial et du pâturage sur l’installation de plantules transplantées initialement germées en serre et de plantules issues de semis in situ. Nos résultats ont montré que les populations de B. retusum sont génétiquement différenciées pour les marqueurs neutres mais également pour les traits phénotypiques. Cette différenciation est supérieure à la dérive seule et suggère une adaptation aux conditions environnementales, en particulier aux températures estivales et à la fréquence du gel en hiver. Une réponse différentielle à la manipulation expérimentale de facteurs environnementaux (sol, pâturage, humidité du sol) a confirmé le caractère adaptatif de la différenciation génétique. Les expériences in situ ont montré que le feu a un effet positif sur la reproduction de B. retusum et sur la communauté végétale associée, alors que son recouvrement végétatif n’était pas supérieur à la moyenne de la communauté. L'exclusion du pâturage pendant deux saisons n'a eu d'incidence sur aucun des paramètres mesurés chez les populations adultes. L'arrosage initial a affecté l’installation des plantules au cours de la première saison. Au cours de la deuxième saison, l'effet seul de l’arrosage n'était pas significatif, cependant son effet est resté positif sur la survie uniquement dans les parcelles pâturées. Le pâturage, au début du cycle de vie de B. retusum, a eu un effet négatif sur le recrutement et la croissance des plantules. En conclusion, la différenciation adaptative entre les populations peut avoir contribué aux différences régionales en termes de capacité de colonisation et doit être prise en compte lors du ciblage des populations sources pour l'introduction de plantes en restauration écologique. La réponse positive de B. retusum a indiqué que le feu était une force sélective importante dans le passé qui pourrait être utilisée pour favoriser l'espèce et la communauté végétale associée dans des opérations de conservation et de restauration. L'exclusion du pâturage à court terme est tolérée par les populations adultes de B. retusum, mais l'abandon à long terme entraîne une diminution de son recouvrement par rapport aux graminées pérennes à croissance rapide. / Ramose false brome (Brachypodium retusum) is a perennial herbaceous species that dominates dry grasslands of the Western Mediterranean. In our southern French study area, spontaneous re-colonisation is very low after soil disturbance. This observation does not correspond to the results of studies from other regions showing a high colonisation capacity. The major objective of this PhD thesis was to test different hypotheses potentially explaining the different colonisation patterns.In the first chapter, we tested whether these different colonisation patterns are the result of genetic differentiation among populations. AFLP markers were used to analyse genetic structure including neutral population differentiation in 17 Western Mediterranean populations. In a sub-sample of 13 French populations, differentiation in phenotypic traits under selection was tested in a common garden and compared to neutral differentiation. In the second chapter, we present a study on adaptive differentiation in phenotypic traits testing a potentially differential response to the manipulation of key environmental factors. The last two chapters of the PhD analysed environmental factors that limit re-colonisation in the field independent of genotype or population. In the third chapter, we tested the effect of grazing and fire on vegetative recovery as well as on sexual reproduction of established B. retusum and in the fourth chapter we measured the effect of initial watering and grazing on the establishment of transplanted seedlings pre-grown in a greenhouse and of field-sown seedlings.Our results showed that populations of B. retusum are genetically differentiated in neutral markers but also in phenotypic traits. This differentiation is superior to drift alone and suggests adaptation to environmental conditions, particularly to summer temperature and winter frost frequency. A differential response to experimental manipulation of environmental factors (soil, pasture, soil moisture) confirmed the adaptive character of genetic differentiation. The field experiments showed that fire has a positive effect on B. retusum reproduction and on the associated community whereas vegetative recovery was not higher than community average. Two seasons of grazing exclosure did not affect any of the measured parameters in adult populations. Initial watering affected seedling establishment in the first season. In the second season, the watering main effect was not significant but interestingly the effect remained positive on survival in grazed plots whereas no such effect was observed in exclosures. Grazing in early life cycle stages of B. retusum had a negative effect on seedling recruitment and growth.In conclusion, adaptive differentiation between populations may have contributed to regional differences in colonisation capacity and needs to be taken into account in targeting source populations for plant introduction in ecological restoration. The positive response of B. retusum indicated that fire was an important selective force in the past which may be used to favour the species and its associated plant community in current conservation and restoration management. Short-term grazing exclosure is tolerated by mature B. retusum populations but long-term abandonment results in a decrease of cover relative to high-growing perennial grasses. In early stages of seedling establishment grazing should be avoided to guarantee introduction success - or grazing stress needs to be compensated by watering.

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