Las zonas de producción de cebada (Hordeum vulgare L.) de Argentina se caracterizan por la variabilidad climática entre sitios y años, causando variaciones de rendimiento por hectárea y en la calidad industrial de los lotes cosechados. El déficit de lluvias durante el ciclo del cultivo causa el mayor impacto en ambos factores. Los programas de mejoramiento de cebada deben considerar y minimizar los efectos de una alta interacción genotipo x ambiente, para que las variedades liberadas tengan menor variación de calidad al ser utilizadas como materia prima de los procesos industriales. La evaluación de calidad mediante micromalteos y análisis de malta es costosa y consume muchotiempo. La detección de loci de caracteres de herencia cuantitativa (QTL) relacionados con calidad en condiciones de sequía podría ser una herramienta de selección para esos ambientes. Otros caracteres como temperatura de canopeo y respuesta al fotoperíodo, también fueron evaluados. Para el mapeo de QTL se utilizó una población de 150 líneas doble haploides, derivadas del cruzamiento entre la línea argentina Mut 6519 y la variedad europea Aspen, ensayada en el período 2007-2011 en cuatro localidades con suelos y regímenes de temperatura y precipitaciones diferentes. Se analizaron rendimiento, contenido de proteína, tamaño de granos, y los principales caracteres de calidad. Se determinó la respuesta fotoperiódica de las líneas mediante ensayos en cinco fechas de siembra, y la temperatura de canopeo en ambientes con y sin déficit de lluvias. Además, se realizaron dos ensayos en la localidad de Fort Collins (Estado de Colorado, EEUU) con y sin riego. Se analizaron 333 marcadores de polimorfismo de longitud de fragmentos amplificados (AFLP) y 27 marcadores de secuencias simples repetitivas o microsatélites (SSR), utilizándose para el mapeo 231 marcadores. Se detectaron 25 QTL en ambientes sin estrés, 8 en estrés moderado, 6 en estrés intenso, y 7 en ambientes con estrés severo, con porcentajes de explicación de la varianza fenotípica (PEV) entre 6,8% y 19,9%. Aún con valores LOD altamente significativos, los PEV de cada uno de los caracteres a través de todos los ambientes fueron bajos (máximo 3,6%). Los QTL que aportaron mayor explicación a los caracteres de calidad se localizaron en los ambientes Tres Arroyos 2007 y 2011 para proteína (11,4% y 10,6%), Puán 2011 (2 QTL) y La Dulce 2010 para humedad de salida de remojo (19,9%, 17,6% y 14,4%), Puán 2010 (2 QTL) y Tres Arroyos 2011 para dureza de malta (13,5%, 11,3% y 13,4%), todos ellos ambientes sin déficit. Los QTL detectados en ambientes con estreses moderados y severos aportaron poca explicación a los caracteres. Las correlaciones entre las herramientas simples utilizadas con todos los caracteres medidos, si bien estadísticamente significativas en algunos casos, fueron bajas como para ser utilizadas con fines de selección. Las distribuciones de frecuencia de cada carácter indicaron herencia transgresiva en casi todos los ambientes, permitiendo seleccionar los genotipos con mejores resultados que el parental de mayor valor para cada carácter. Los métodos que combinan los rankings de caracteres en ambientes contrastantes, y el análisis de estabilidad de los resultados de una cantidad grande de ambientes con y sin limitaciones, serían las herramientas más efectivas para seleccionar genotipos con mejores aptitudes productivas. / Barley (Hordeum vulgare L.) crop areas in Argentina display climatic variability between sites and years, causing variations in yield and in industrial quality of the harvested lots. Rainfall deficit during the crop cycle causes the greatest impact on both factors. Barley breeding programs have to consider and minimize the effects of a hig genotype x environment interaction, so that the released varieties have less variation in quality when used as raw material for industrial processes. Malting quality evaluation by micromalting and malt analysis is expensive and time-consuming. Detection of quantitative traits loci (QTL) related to industrial quality in drought conditions could be a selection tool in those environments. Other characters such as canopy temperature and photoperiod response were also evaluated. For QTL mapping, a population of 150 double haploid lines was used, derived from the crossing between the Argentine line Mut 6519 and the European variety Aspen, tested during the period 2007-2011 in four locations with different soils and temperature and rainfall regimes. Yield, barley protein, grain size, and the main industrial quality characters were analyzed. Photoperiodic response of the lines was evaluated by trials in five sowing dates, and the same was canopy temperature in environments with and without rainfall deficit. In addition, two trials were conducted in Fort Collins (State of Colorado, USA) with and without irrigation. Three hundred and thirty three amplified fragment length polymorphism markers (AFLP) and 27 simple sequence repetitive or microsatellite markers (SSR) were analyzed, using 231 markers for the mapping. Twenty five QTL were detected in stress-free environments, 8 in moderate stress, 6 in intense stress, and 7 in environments with severe stress, with percentage of explained phenotypic variation (PEV) between 6.8% and 19.9%. Even with highly significant LOD values, the PEV of each character across all the environments was low (maximum 3.6%). QTL that provided the highest explanation for quality traits were located in Tres Arroyos 2007 and 2011 for protein (11.4% and 10.6%), Puán 2011 (2 QTL) and La Dulce 2010 for steeping out(19.9%, 17.6% and 14.4%), Puán 2010 (2 QTL) and Tres Arroyos 2011 for malt hardness (13.5%, 11.3% and 13.4%), all environments without water deficit. The QTL detected in environments with moderate and severe stress contributed little explanation to the characters. The correlations between simple tools used with all the measured characters, although statistically significant in some cases, were too low to be used for selection purposes. Observations of the frequency distributions of each character indicated transgressive inheritance in almost all environments, allowing selecting the genotypes with better results than the parent of greater value for each trait. The methods that combine the character ranking in contrasting environments, and the stability analysis of the results in a high amount of environments with and without limitations, would be the most effective tool to select genotypes with best productive aptitudes.

Field pea (Pisum sativum L.) as a cool season legume crop is sensitive to high day time temperature, especially during flowering. A population of 107 recombinant inbred lines (RILs) known as PR-11 was made from the cross of CDC Centennial (heat tolerant cultivar) X CDC Sage (heat sensitive cultivar) with the objectives of screening heat tolerant traits during flowering and subsequent seed development, and to map the quantitative trait loci (QTLs) responsible for these traits. Experiments were carried out in 2012-2014. PR-11 was seeded at normal seeding dates in 2012 and 2013 at Saskatoon (52º12’N, 106º63’W) and Rosthern (52º66’N, 106º33’W) in Canada, and in 2014 PR-11 was seeded at both normal and late seeding (three weeks later than normal) dates at one location, Saskatoon. Correlation analyses demonstrated that the duration of flowering (DOF) was positively associated with final seed yield under both normal and late seeding date conditions. Yield component traits on the main-stem [reproductive node number (Rnode), pod number (Pod), seed number per pod (Seed), single seed weight (SSW)] were significantly associated with main-stem seed yield, among which pod number appeared to be the component most positively associated with seed yield. However, yield on the main-stem was not significantly associated with seed yield at the plot level, which inferred that the contribution of seed yield on side branches was important. A genetic map consisting of 369 SNPs markers with a total coverage of 746 cM was developed using JoinMap 4.0. A total of 14 QTLs were detected under environments with normal seeding date, six for flowering traits, and eight for yield component traits. Eight QTLs were identified at late seeding, four for flowering traits and four for yield component traits. The total variation in days to flowering (DTF), DOF, Pod, Seed, SSW and grain yield that were each explained by the QTLs under normal seeding environments was 24 %, 43%, 15%, 32%, 34% and 21%, respectively. The QTLs together accounted for 43% of DTF variation, 14% of DOF variation, 17% of Pod variation, 12% of SSW variation and 12% of grain yield variation at the late seeding date. Lines PR-11-2, PR-11-88 and PR-11-91 performed as the top yielding lines under both normal and late seeding environments, and could be considered as heat tolerant lines.

L'un des défis auxquels sont confrontés les producteurs de fruits est de réussir à maintenir d'année en année un équilibre entre croissance végétative et production. La productivité des arbres fruitiers au cours des années est étroitement liée à leur développement. Intégrer les caractères architecturaux dans les programmes de sélection pourrait donc, améliorer la régularité de production et aider à optimiser la gestion des cultures. Dans cette thèse, nous avons étudié le déterminisme génétique des caractères architecturaux chez l'olivier (Olea europaea L. subsp. Europaea), en incluant le développement végétatif et reproducteur. L'olivier a un grand intérêt en raison de l'importance de l'huile d'olive et des olives dans l'alimentation humaine. L'étude a porté sur une descendance issue du croisement entre les variétés 'Olivière' et ‘Arbequina' qui a été cultivée en verger dans deux environnements contrastés. En premier lieu, nous avons étudié le déterminisme génétique de la croissance et ramification des arbres durant la phase juvénile sur un site en considérant trois échelles d'observation: arbre, unité de croissance et entrenœuds. Les interactions entre les facteurs liés à l'ontogénie de l'arbre ainsi que les facteurs génotype et environnement ont été prises en compte. Des modèles génétiques, incluant les effets année de croissance et/ou ordre de ramification, environnement, génotype et leurs interactions respectives, ont été construits en intégrant une fonction de variance et une structure de covariance lorsque cela était nécessaire. Après une étape de sélection de modèle, les facteurs impactant significativement l'architecture de l'arbre ont été identifiés et les valeurs d'héritabilité au sens large ont été estimées. Ces résultats nous ont permis de définir à quel moment au cours de l'ontogenèse de l'olivier et à quelle échelle d'observation, les caractères de croissance et ramification sont déterminés génétiquement. De plus, cette étude a permis d'investiguer la plasticité des caractères architecturaux et leur stabilité entre environnements contrastés. Enfin, les changements associés à l'acquisition des facultés reproductives ont été observés. Quand tous les descendants ont atteint l'âge adulte, j'ai étudié les bases génétiques du développement reproducteur. La stratégie était basée sur (i) une décomposition d'un sous échantillon d'unités de croissance localisées à la périphérie de la couronne de l'arbre en variables quantitatives liées à la fois aux processus de floraison et fructification en relation avec leur croissance et ramification (ii) une évaluation annuelle du rendement des arbres durant quatre années. L'observation d'arbres 'ON' ou ‘OFF' pour une année donnée a révélé des tendances de production régulière vs irrégulière au sein de la descendance. Après avoir développé une nouvelle carte génétique, une recherche QTLs associés aux caractères reproductifs a été réalisée. Des QTLs présentant les effets des deux parents et des co-localisations ont été identifiés. Cette étude a mis en évidence le schéma de développement de l'olivier pendant les phases juvénile et mature mettant en évidence l'existence de gradients ontogéniques se traduisant par des caractères héritables qu'à la périphérie de l'arbre. Une stratégie de phénotypage adaptée aux caractéristiques architecturales de l'olivier a été proposée. Enfin, les descendants montrant une supériorité intéressante par rapport à leurs parents ont été identifiés. Ces génotypes pourraient être valorisés dans les programmes de sélection futurs pour la création de variétés innovantes. / One of the most challenging questions that fruit growers are facing is to maintain trees in a stable balance between production and vegetative growth from year to year. Fruit trees productivity over years is closely linked to their development. Integrating architectural traits in breeding programs could thus, optimise cultivation management and improve bearing regularity. Here, we investigate the genetic determinism of architectural traits in the olive tree (Olea europaea L. subsp. europaea) including vegetative and reproductive behaviour. The olive tree raises high interest because of the importance of olive oil and olives in the human diet. The segregating population under study derived from a cross between ‘Olivière' and ‘Arbequina' cultivars and was grown on two orchards under contrasting environments. First, we investigated the genetic determinism of juvenile growth and branching traits in one site at three different scales: whole tree, growth unit and internodes. Interaction between tree ontogeny, genetic and environmental factors were considered. Genetic models, including the year of growth, environment, genotype effects and their interactions, were built with variance function and covariance structure of residuals when necessary. After a model selection step, morphogenetic factors impacting significantly tree architecture were identified and heritabilities were estimated. These finding allow us to define when during the olive tree ontogeny and at which observation scale, growth and branching traits are under genetic influence. Moreover, progenies plastic response to contrasted environments was highlighted and traits showing significant genotype-by-environment effect were identified. Changes over time associated to the acquisition of reproductive competence were further observed. Once all progenies attempt adulthood, we studied the genetic basis of reproductive behaviour. Our strategy was based on (i) a decomposition of adult growth units at the crown periphery in quantitative variables related to both flowering and fruiting process in relation to their growth and branching (ii) an annual assessment of individual trees yield. The observation of ‘on' or ‘off' olive trees in a given year over four years revealed patterns of regular vs. irregular bearing. After developing a new genetic map, a QTL mapping was carried out on reproductive traits, leading to the identification of QTLs with effects from both parents and co-localizations. This study gives an overview of olive tree development during juvenility and maturity periods showing the existence of ontogenic trends, which result in traits heritable mostly at the tree periphery. A phenotyping strategy adapted to its architectural characteristics is proposed. Finally, progenies showing interesting superiority in comparison to their parents were identified and could constitute interesting sources for innovative materials in future selection programs.

Made available in DSpace on 2016-12-23T14:37:30Z (GMT). No. of bitstreams: 1 Joao Felipe Brites Senra.pdf: 1222145 bytes, checksum: 43a5bc32cc332c65c3a59a5950d50c5d (MD5) Previous issue date: 2013-03-27 / Brazil is a major world producer of soybeans, its cultivation being well distributed throughout the country. The culture is characterized by the potential for production of isoflavones, phytoestrogens naturally occurring in plants and chemical structure comparable to that of estradiol. The principal isoflavone aglycones are (genistein, daidzein and glycitein) and β-glucoside (genistin, daidzin and glycitin, 6 "-O-acetyl genistin, 6"-O-acetyl daidzin and 6 "-O-acetyl glycitin, 6 "-O-malonyl genistein, 6"-O-malonyl daidzein, 6 "-O-malonyl glycitin). There are reports on the beneficial effects of these on human health, and the reduction of coronary heart disease, delay the manifestation of atherosclerosis, have beneficial effects on hypercholesterolemia, protects against various types of cancer and improving hormonal activity. In plants isoflavones stimulate soil microorganism Bradirizobium, the formation of nodules on the roots and for fixing activity against pathogenic fungi and increases resistance to attack by aphids. Through the benefits of isoflavones in the feed, their influence on plant physiology and complexity of their extraction and quantification, it is necessary to evaluate and study the genetic control of this characteristic estimating the molecular markers linked to the QTL that control them. The objective of this work was to map and validate QTLs for isoflavone using recombinant inbred lines RIL (Recombinant Imbred Lines) and compare the results obtained by simple interval mapping (IM Simple Interval Mapping) and composite interval mapping (CIM Composite Interval Mapping). The population consists of recombinant inbred lines RIL (Recombinant Imbred Lines) belonging to soybean breeding program at the Federal University of Viçosa, from the cross between the cultivar Hartwig and lineage Y-23, contrasting the content of daidzin, glycitin, genistin , malonyl daidzin, malonyl glycitin, acetyl daidzin, daidzein, acetyl genistin, genistein, daidzein, total genistein total glycitein total, and total isoflavones. The extraction process was performed by high performance liquid chromatography (HPLC), and quantified by external standard, and the results obtained in μg.g-1. Markers were used 133 polymorphic, which was obtained with a linkage map with 24 linkage groups, recombination frequency of 25 cM and a minimum LOD of 3.0. Mapping was carried out by simple brand MAS (single-marker locus analysis) by analysis of variance and regression, by the method of simple interval (IM, simple interval mapping), by the method of regression and maximum likelihood, and the composite interval mapping (CIM composite interval mapping). The positioning of QTL was performed by permutation test with 10,000 permutations, allowing establish significance levels of 5 and 1%. In the characteristics malonyl daidzin and acetyl genistin were not transgressive lines. The genotype 2.27 presented the highest levels in eight isoflavones and 4.75 in the lower 12. There are high correlations between the group DAC with isoflavones genistin, genistein and genistein total and low glycitin between DAC and genistin, genistein and genistein total. QTLs were validated in GLs A2, D2, E, H, K, M and N for CAD, C2, D2, K and M for GEC in A2, C2, D1a, D2, H, K, M and N for GLC and total isoflavone in GLs G, H and O. In GL G were found QTLs of large effect for DAC, and a large number of QTLs for GEC, although not mentioned in this GL QTLs for these isoflavones. There is evidence of a relationship between genetic control of resistance to the cyst nematode and isoflavones in this population due to the proximity of the QTL controlling these traits. The most efficient method of mapping the CIM was due to the selection of cofactors that allowed QTL eliminate ghosting, which was not possible for the IM method and maximum likelihood regression. The mapping CIM detected by 44, 40, 29 and 10 QTLs for CHD, GEC, GLC and total isoflavones respectively. The IM regression positioned nine, five, four and two QTL for CAD, GEC, GLC and total isoflavones respectively. The IM approach by maximum likelihood for DAC positioned six QTLs for GEC and 12 respectively / O Brasil é um dos grandes produtores mundiais de soja, sendo o seu cultivo bem distribuído no território nacional. A cultura caracteriza-se pelo potencial para produção de isoflavonas, fitoestrógenos de ocorrência natural nas plantas e com estrutura química comparável a do estradiol. As principais isoflavonas são as agliconas (genisteína, daidzeína e gliciteína) e as β-glicosídeo (genistina, daidzina e glicitina, 6 "-O-acetil genistina, 6"-O-acetil daidzina e 6 "-O-acetil glicitina, 6 "-O-malonil genistina, 6"-O-malonil daidzina, 6 "-O-malonil glicitina) Existem relatos sobre a influência benéfica destes sobre a saúde humana, quanto a redução de doenças coronarianas, retardam a manifestação de arteriosclerose, possuem efeitos benéficos na hipercolesterolemia, protegem contra diversos tipos de câncer e melhoria da atividade hormonal. Nas plantas as isoflavonas estimulam o microrganismo Bradirizobium do solo, a formação de nódulos nas raízes para fixação e atividade contra fungos fitopatogênicos e aumenta a resistência ao ataque de pulgões. Mediante os benefícios das isoflavonas na alimentação, sua influência na fisiologia da planta e a complexidade de sua extração e quantificação, torna-se necessário avaliar e estudar o controle genético desta característica, estimando os marcadores moleculares ligados aos QTLs que as controlam. O objetivo deste trabalho foi mapear e validar QTLs para isoflavonas utilizando linhagens endogâmicas recombinantes RIL (Recombinant Imbred Lines) e comparar os resultados obtidos pelo mapeamento por intervalo simples (IM Simple Interval Mapping) e mapeamento por intervalo composto (CIM Composite Interval Mapping). A população é constituída por linhagens endogâmicas recombinantes RIL (Recombinant Imbred Lines) pertencentes ao programa de melhoramento de soja da Universidade Federal de Viçosa, oriundas do cruzamento entre a cultivar Hartwig e a linhagem Y-23, contrastantes para o teor de daidzina, glicitina, genistina, malonil daidzina, malonil glicitina, acetil daidzina, daidzeína, acetil genistina, genisteína, daidzeína total, genisteína total, gliciteína total, e isoflavonas totais. O processo de extração foi realizado por cromatografia líquida de alta eficiência (HPLC high performance liquid chromatography), e a quantificação por padronização externa, sendo os resultados obtidos em μg.g-1. Foram utilizados 133 marcadores polimórficos, com os quais foi obtido um mapa de ligação com 24 grupos de ligação, frequência máxima de recombinação de 25 cM e LOD mínimo de 3,0. Foi realizado o mapeamento por marca simples MAS (single-marker locus analysis) por análise de variância e regressão, pelo método do intervalo simples (IM, simple interval mapping), pelo método da regressão e da máxima verossimilhança, e o mapeamento pelo intervalo composto (CIM, composite interval mapping). A determinação da posição do QTL foi realizada pelo teste de permutação, com 10000 permutas, possibilitando estabelecer níveis de significância de 5 e 1%. Nas características malonil daidzina e acetil genistina não ocorreram linhagens transgressivas. O genótipo 2.27 apresentou as maiores concentrações em oito isoflavonas e o 4.75 as menores em 12. Existem altas correlações entre as isoflavonas do grupo DAC com genistina, genisteína e genisteína total e baixa entre glicitina com DAC e genistina, genisteína e genisteína total. Foram validados QTLs nos GLs A2, D2, E, H, K, M e N para DAC, em C2, D2, K e M para GEC, em A2, C2, D1a, D2, H, K, M e N para GLC e para isoflavonas totais no GLs G, H e O. No GL G foram encontrados QTLs de grande efeito para DAC, e um grande número de QTLs para GEC, apesar de não serem citados QTLs neste GL para estas isoflavonas. Existem indícios de relação entre controle genético da resistência ao nematoide do cisto e isoflavonas nesta população, devido à proximidade dos QTLs que controlam estas características. O método mais eficiente de mapeamento foi o CIM, em virtude da seleção de cofatores que permitiu eliminar os QTL fantasmas, o que não foi possível pelo IM pelo método da regressão e máxima verossimilhança. O mapeamento pelo CIM detectou 44, 40, 29 e 10 QTLs para DAC, GEC, GLC e isoflavonas totais respectivamente. O IM por regressão posicionou nove, cinco, quatro e dois QTL para DAC, GEC, GLC e isoflavonas totais respectivamente. O IM pela abordagem da máxima verossimilhança posicionou seis QTLs para DAC e 12 para GEC respectivamente

Submitted by Reginaldo Soares de Freitas (reginaldo.freitas@ufv.br) on 2016-09-21T17:59:17Z No. of bitstreams: 1 texto completo.pdf: 382726 bytes, checksum: 351ccc02a1b72003c1e584b1d1acb6b8 (MD5) / Made available in DSpace on 2016-09-21T17:59:17Z (GMT). No. of bitstreams: 1 texto completo.pdf: 382726 bytes, checksum: 351ccc02a1b72003c1e584b1d1acb6b8 (MD5) Previous issue date: 2000-02-11 / Fundação de Amparo à Pesquisa do Estado de Minas Gerais / Uma população de 118 RIL’s (linhagens recombinantes endogâmicas) foi obtida através do cruzamento entre o acesso BARC-8 (com alto teor de proteína) e a variedade brasileira Garimpo (com teor de proteína normal). Na geração F6 foram abertas linhas, que constituíram o material genético utilizado neste trabalho. Esse material foi analisado, utilizando-se marcadores microssatélites. Foi feita também a análise do teor de proteínas para essa população cultivada em dois ambientes distintos: Cascavel, PR, e Viçosa, MG. Análise de regressão simples e múltipla e mapeamento por intervalo composto foram utilizados para detectar e mapear as regiões genômicas associadas com alto teor de proteína. A proporção da variância fenotípica explicada por marcador variou entre 3,25% e 6,37% em Cascavel e entre 2,92 % e 12,43% em Viçosa. Na análise de regressão múltipla, os marcadores Satt190, Satt384, Satt422 e Sat-105 explicaram aproximadamente 23% do total da variação do teor de proteínas (Cascavel), e os marcadores Satt190, Satt384, Satt012, Satt304, Satt369 e Sat-105 explicaram, juntos, aproximadamente 31% do total da variação do teor de proteínas em Viçosa. Utilizando-se as médias dos teores de proteína dos dois locais, dois marcadores mostraram-se estáveis nos dois ambientes: Satt384 e Sat-105. Esses marcadores estão associados a genes conservados, cujas funções estão ligadas à determinação do conteúdo de proteínas na semente. No mapeamento por intervalo composto, foram encontrados dois QTL’s associados a teor de proteína nos grupos de ligação C1 e C2, para as famílias cultivadas em Cascavel, que explicam, respectivamente, 11,13% e 12,19% da variação do teor de proteínas. Outras regiões foram encontradas nos grupos de ligação B2, C1, G, K (Viçosa) e E (Cascavel), mas a ligação entre essas regiões e o conteúdo de proteínas não foi significativa nas condições do teste de ligação efetuado. / A soybean population of 118 RILs (recombinant inbred lines) obtained from the cross between the accession BARC - 8 (genotype with high protein content, around 50%) and the brazilian commercial variety Garimpo (genotype with normal protein content, around 36%) was used for the construction of a molecular linkage map, with SSR markers, and for identifying QTLs which control protein level in soybean seeds. F6 generations were grown in two distinct locations (Viçosa, MG and Cascavel, PR) in the summer of 1998/99. Protein contents in the seeds from each line cultivated in the two locations were determined by the Kjedahl method. DNA samples purified from leaves from each line of the population were amplified with 567 soybean SSR primers. Sixty five SSR markers were polymorphic and segregated in a 1:1 ratio in the population. Single and multiple regression and composed interval mapping analysis were used to detect genomic regions associated with high protein content. The SSR markers were also used to construct a molecular genetic map containing 16 linkage groups. The proportion of the phenotypic variance explained by the markers varied from 3,25% to 6,37% in Cascavel, and from 2,92% to 12,43% in Viçosa. Multiple regression analysis identify that markers Satt190, Satt384, Satt422 and Sat-105 explained 23% of the total protein content variation in the RILs cultivated in Cascavel, PR, and Satt190, Satt384, Satt012, Satt304, Satt369 and Sat-105 explained 31% of the total protein content variation in the RILs grown in Viçosa, MG. By using mean values of protein content of the two places, markers Satt384 and Sat-105 shown to be stable in the two environment. It is proposed that these markers are associated with conserved genes, whose functions are very important in protein synthesis and deposition in the seed. Composed interval mapping analysis identified two QTL's associated with protein content in linkage groups C1 and C2 for RIL’s cultivated in Cascavel, which explained, respectively, 11,13% and 12,19% of protein content variation. Other genomic regions were detected in linkage groups B2, C1, G, K (Viçosa) and E (Cascavel), but with no significative correlation with protein content based on the test used. / Não foi localizado o cpf do autor.

Ralstonia solanacearum est une bactérie vasculaire d'origine tellurique dévastatrice chez les Solanacées maraîchères. L'une des difficultés pour la sélection variétale réside dans le contournement de la résistance, en raison de la grande variabilité et plasticité génotypique du pathogène. Trente accessions de tomate, aubergine et piment (Core-TEP) testées vis-à-vis de 12 souches représentatives des phylotypes I, II et III de R. solanacearum (Core-Rs2) ont été classées de très sensibles à très résistantes. Des groupes de souches définis en fonction de leur virulence et agressivité ont été nommés pathoprofils, d'une part, lorsque établis sur les 3 espèces et pathotypes, d'autre part, lorsque établis sur chacune des trois espèces. Aucune résistance universelle n'a pu être mise en évidence chez aucune des trois espèces. Le déterminisme génétique de la résistance à R. solanacearum chez l'aubergine a été étudié sur une population de lignées recombinantes F6 ainsi que sur les générations issues du croisement intraspécifique S. melongena MM738 (S) x AG91-25 (R), testées vis-à-vis de quatre souches du phylotype I. Une carte génétique composée de 119 marqueurs AFLP, SSR et SRAP, positionnés sur 18 groupes de liaisons, pour une longueur totale de 884 cM, a été construite. Les analyses génétiques montrent que la résistance aux souches CMR134, PSS366, GMI1000 est contrôlée par un même gène majeur expliquant jusqu’à 87% de la variance phénotypique. Celui-ci n'est pas détecté vis-à-vis de la souche virulente PSS4 qui contourne cette résistance. Dans ce cas, seul un QTL à effet intermédiaire expliquant jusqu’à 38 % de la variance phénotypique est trouvé sur un autre groupe de liaison. / The plant pathogenic soil-borne bacteria Ralstonia solanacearum causes heavy damage to solanaceous crops. One of the dilemmas for varietal breeding of solanaceous crops is the circumvention of the resistance to R. solanacearum due to the genotypic variability and plasticity of this pathogen. Thirty accessions of Tomato, Eggplant, and Pepper (Core-TEP), screened with a collection of 12 representatives strains of R. solanacearum phylotype I, II and III (Core-Rs2) within the species complex ranked from highly resistant to highly susceptible. The strains were grouped according to there profile of virulence on all three solanaceous, and by considering each species individually. We refer to these groups respectively, as pathoprofiles and pathotypes. No universal resistance was found for the three host species. Genetic analysis of resistance to R. solanacearum in eggplant was conducted against four strains of phylotype I. We used a population of recombinant lines F6 as well as the generations derived from the intraspecific cross between S. melongena MM738 (S) and AG91-25 (R). A genetic map was built with 119 markers a combination of AFLPs, SSRs and SRAPs positioned on 18 linkage groups, for a total length of 884 cM. The genetic analysis revealed that resistance to strains CMR134, PSS366, and GMI1000 was controlled by one single major gene, which explained up to 87% of the phenotypic variation. When the resistance against the highly virulent PSS4 strain is tested, this gene is not detected. In this case, a significant QTL with intermediate effect that explains up to 38% of phenotypic variation was found on another linkage group for this strain.

Les nématodes gastro-intestinaux sont des parasites de la caillette des petits ruminants qui posent des contraintes majeures pour l’élevage de ces animaux dans le monde. Récemment leur impact économique a augmenté notamment à cause de l’apparition de nématodes résistants aux anthelminthiques. La sélection génétique pourrait être une stratégie complémentaire des traitements chimiques. Dans cette thèse, nous avons exploré la variabilité génétique disponible qui permettrait une sélection sur la résistance aux nématodes. Les résultats obtenus en termes d’héritabilités, corrélations génétiques et QTLs, suggèrent que la variation génétique des populations étudiées pourrait satisfaire les requis d’un objectif de sélection permettant à la fois d’améliorer la résistance aux nématodes et la croissance des animaux. En outre, l’identification de loci SNP associés à la variation observée sur les caractères de résistance aux nématodes pourrait nous permettre d’améliorer la réponse à la sélection. / Abomasal nematodes are a major constraint to small ruminants industry worldwide. Recently their economic impact has increased due to the recrudescence of anthelmintic resistance among many parasite populations. Genetic selection might be a valid strategy for enhancing the efficacy of anthelmintics. We explored the genetic variability, in both sheep and goat, possibly available for a breeding plan featuring parasite resistance as its breeding goal. The results obtained in terms of heritabilities, genetic correlations and QTLs, suggest that the variation in the genetic pool of the population under study might comply with the requirements of a breeding goal including both parasite resistance and production traits. Furthermore, marker assisted selection could be a feasible option to enhance the selection response.

Le premier objectif de cette thèse était de déterminer les effets isolés et combinés de l'alpha thalassémie, des polymorphismes inducteurs (QTLs) de l'HbF et du génotype G6PD dans un contexte d'évolution naturelle de la drépanocytose (Etudes 1 et 2). L'étude 1 a permis d'évaluer pour la première fois les fréquences alléliques de ces gènes modificateurs chez 301 enfants sénégalais SS. Contrairement aux autres populations africaines, le Variant Betica de la G6PD était majoritaire par rapport au variant A(-). De plus, 12% de notre cohorte avait un déficit en G6PD combiné à une absence d'alpha-thalassémie. Ces patients-là seront à privilégier pour la réalisation d'un Doppler transcrânien. Les résultats obtenus dans l'étude 2 nous ont permis de conclure que l'alpha-thalassémie et les QTLs de l'HbF sont interdépendants et ne doivent pas être étudiés séparément pour une prédiction clinique précise. En effet, une combinaison d'alpha-thalassémie avec au moins 2 QTLs de l'HbF est nécessaire pour retarder de manière significative la première complication de la maladie. Cependant, une alpha-thalassémie homozygote, même associée à 3 à 6 QTLs de l'HbF, augmente la fréquence des CVO pendant l'enfance. Par conséquent, une alpha-thalassémie hétérozygote avec au moins deux QTL HbF constituerait le génotype le plus favorable relativement à la survenue des CVO. Le deuxième objectif de cette thèse était d'étudier les interrelations entre le stress oxydant (phénotype et génotype) et la sévérité clinique de la maladie (Etudes 3 à 4). La drépanocytose est caractérisée par un stress oxydatif élevé pouvant expliquer une partie des manifestations cliniques. Nos résultats ont montré que l'alpha-thalassémie homozygote semble diminuer le stress oxydatif, ce qui contribuerait à son effet protecteur sur certaines complications du sous-phénotype hémolytique. En outre, les patients qui ont le moins d'hospitalisations et de CVO semblent présenter une meilleure défense antioxydante (activités catalase et GPx augmentées). Dans l'étude 4 nous avons étudié 4 SNPs de gènes du stress oxydant (rs4880 du gène SOD2, rs207454 du gène XO, rs233322 du gène MPO et rs35652124 du gène NFE2L2). Le SNP rs4880 aurait un effet favorable au niveau biologique (réticulocytose moindre, activité GPx augmentée) mais sans traduction clinique associée. Il en est de même pour rs233322 qui serait associé à une hémolyse et à un stress oxydatif (AOPP) plus importants. En revanche, une tendance à un effet protecteur de rs207454 vis-à-vis de certaines complications (hospitalisations, ostéonécrose, sepsis, STA) a été observée. Notre travail contribue à la compréhension de l'impact des gènes modificateurs dans la drépanocytose. Il pourrait donc permettre, via une sélection positive des patients à risque, d'améliorer la prise en charge de la maladie dans les pays où les traitements de fond (hydroxyurée, doppler transcrânien, échanges transfusionnels) ne peuvent être proposés à tous / The primary objective of this thesis was to determine the isolated and combined effects of alpha-thalassemia, inductors polymorphisms (QTLs) of HbF and genotype G6PD in a context of natural progression of sickle cell disease (Studies 1 and 2). Study 1 was undertaken to evaluate for the first time the allelic frequencies of these modifiers genes in 301 Senegalese SS children. Unlike other African populations, the G6PD Betica Variant was predominant over the A (-) variant. In addition, 12% of our cohort had G6PD deficiency combined with no alpha-thalassemia. These patients will be favoured for the realization of a transcranial doppler. The results obtained in Study 2 allowed us to conclude that alpha thalassemia and QTLs of HbF are interdependent and should not be studied separately for accurate clinical prediction. Indeed, a combination of alpha thalassemia with at least 2 QTLs of HbF is required to significantly delay the first complication of the disease. However, a homozygous alpha thalassemia, even associated with 3 to 6 QTLs of HbF, increases the frequency of CVOs during childhood. Therefore, a heterozygous alpha-thalassemia with at least two QTL HbFs would be the most favourable genotype for the occurrence of CVOs. The second objective of this thesis was to study the interrelationships between oxidative stress and the clinical severity of the disease (Studies 3 to 4). Sickle cell disease is characterized by high oxidative stress that may explain some of the clinical manifestations. Our results showed that homozygous alpha-thalassemia appears to reduce oxidative stress, which would contribute to its protective effect on certain complications of the hemolytic sub-phenotype. In addition, patients with the least hospitalization and CVO appear to have better antioxidant defense (catalase and GPx activities increased). In Study 4 we studied 4 SNPs of oxidative stress genes (rs4880 of the SOD2 gene, rs207454 of the XO gene, rs233322 of the MPO gene and rs35652124 of the NFE2L2 gene). The rs4880 SNP would have a favourable effect on the biological level (less reticulocytosis, increased GPx activity) but without associated clinical translation. The same is true for rs233322, which is associated with greater haemolysis and oxidative stress (AOPP). On the other hand, a tendency to a protective effect of rs207454 for some complications (hospitalizations, osteonecrosis, sepsis, STA) was observed. Our work contributes to the understanding of the impact of modifiers genes in sickle cell disease. It could therefore, through a positive selection of at-risk patients, improve the management of the disease in countries where the basic treatments (hydroxyurea, transcranial doppler, blood transfusion) cannot be offered to all

Abstract Drought is the most common abiotic stress limiting chickpea production in the world. Ninety percent of the worlds chickpea is produced in areas relying upon conserved, receding soil moisture, therefore, crop productivity is largely dependent on efficient utilization of available soil moisture. Because of the variability in drought pattern from year to year, trait based selection could have an advantage over selection on the basis of grain yield alone. Trait based breeding, however, requires trait dissection into components. Successful marker identification would facilitate integration of MAS procedures in breeding programs enabling the pyramiding of favourable alleles.<p> The genetic map produced in this study was based on a population of recombinant inbred lines of a cross of ILC 588 x ILC 3279 containing 52 SSR markers spanned 335 cM of the chickpea genome at an average density of 6.4 cM. A total of 13 genomic regions were shown to be associated with drought tolerance traits. Some of these genomic regions showed pleiotropic effect on multiple traits. This was also supported by the analysis of phenotypic data where these traits were found to be correlated. For example, early flowering and maturity had a strong association with high grain yield. High grain yield was also associated with better portioning ability between biomass and grain yield, i.e. harvest index. Drought tolerance score (DTS) was associated with various important traits including biomass, early flowering, early maturity.<p> This study also concluded that chickpea genotypes differed in terms of root length, root length density, root weight density and root length to weight ratio at every 20 cm soil layer up to 100 cm depth in response to water deficits. Consideration of an efficient root system vs. a larger root system is also important, since in this research, large root systems were offset by low harvest index, presumably due to the lack of assimilate available for grain growth. A restricted root system is important in environments like Western Canada, where crop growth termination is usually required prior to fall frost. This study also reported significant associations of stomatal conductance (gs) with each of HI, grain yield under drought, drought susceptibility index and drought tolerance score (DTS). Stomatal conductance can also be used to assess plant stress due to drought. Values of gs less than 250 mmol m-2s-1 during flowering indicated drought stress under greenhouse conditions. A higher degree of plant stress due to drought was shown by increased stomatal closure at midday (gs <150 mmol m-2s-1). The study of 157 RILs under natural drought stress during 2005-07 revealed that the 17 RILs which had high grain yield under drought (Group A), also tended to have higher gs than the 42 RILs that had lower grain yield (Group B). Group A had mean gs values of 390 mmol m-2s-1 during the week before flowering, while Group B had mean gs value of 330 mmol m-2s-1. Stomatal conductance increased at flowering and then sharply decreased later in the reproductive period, particularly in Group B. These findings were also supported by canopy temperature differential measurements as Group A was also able to maintain lower canopy temperature than Group B, indicating the ability of these plants to maintain adequate transpiration and a cooler canopy under drought stress. This research indicated that gs and canopy temperature can be used to assess chickpea drought stress and to screen drought tolerant genotypes. This study identified a QTL on LG7 for gs, QTLs on LG1, LG3 and LG6 associated with canopy temperature differential, as well as QTLs associated with grain yield under drought, HI, DTS, days to flower, days to maturity, reproductive period and plant height. These QTLs identified for traits related to higher chickpea productivity under drought stress could have important implications for accelerating the process of pyramiding of favourable genes into adapted genotypes and on future marker-assisted breeding for drought prone areas.

Abstract Drought is the most common abiotic stress limiting chickpea production in the world. Ninety percent of the worlds chickpea is produced in areas relying upon conserved, receding soil moisture, therefore, crop productivity is largely dependent on efficient utilization of available soil moisture. Because of the variability in drought pattern from year to year, trait based selection could have an advantage over selection on the basis of grain yield alone. Trait based breeding, however, requires trait dissection into components. Successful marker identification would facilitate integration of MAS procedures in breeding programs enabling the pyramiding of favourable alleles.<p> The genetic map produced in this study was based on a population of recombinant inbred lines of a cross of ILC 588 x ILC 3279 containing 52 SSR markers spanned 335 cM of the chickpea genome at an average density of 6.4 cM. A total of 13 genomic regions were shown to be associated with drought tolerance traits. Some of these genomic regions showed pleiotropic effect on multiple traits. This was also supported by the analysis of phenotypic data where these traits were found to be correlated. For example, early flowering and maturity had a strong association with high grain yield. High grain yield was also associated with better portioning ability between biomass and grain yield, i.e. harvest index. Drought tolerance score (DTS) was associated with various important traits including biomass, early flowering, early maturity.<p> This study also concluded that chickpea genotypes differed in terms of root length, root length density, root weight density and root length to weight ratio at every 20 cm soil layer up to 100 cm depth in response to water deficits. Consideration of an efficient root system vs. a larger root system is also important, since in this research, large root systems were offset by low harvest index, presumably due to the lack of assimilate available for grain growth. A restricted root system is important in environments like Western Canada, where crop growth termination is usually required prior to fall frost. This study also reported significant associations of stomatal conductance (gs) with each of HI, grain yield under drought, drought susceptibility index and drought tolerance score (DTS). Stomatal conductance can also be used to assess plant stress due to drought. Values of gs less than 250 mmol m-2s-1 during flowering indicated drought stress under greenhouse conditions. A higher degree of plant stress due to drought was shown by increased stomatal closure at midday (gs <150 mmol m-2s-1). The study of 157 RILs under natural drought stress during 2005-07 revealed that the 17 RILs which had high grain yield under drought (Group A), also tended to have higher gs than the 42 RILs that had lower grain yield (Group B). Group A had mean gs values of 390 mmol m-2s-1 during the week before flowering, while Group B had mean gs value of 330 mmol m-2s-1. Stomatal conductance increased at flowering and then sharply decreased later in the reproductive period, particularly in Group B. These findings were also supported by canopy temperature differential measurements as Group A was also able to maintain lower canopy temperature than Group B, indicating the ability of these plants to maintain adequate transpiration and a cooler canopy under drought stress. This research indicated that gs and canopy temperature can be used to assess chickpea drought stress and to screen drought tolerant genotypes. This study identified a QTL on LG7 for gs, QTLs on LG1, LG3 and LG6 associated with canopy temperature differential, as well as QTLs associated with grain yield under drought, HI, DTS, days to flower, days to maturity, reproductive period and plant height. These QTLs identified for traits related to higher chickpea productivity under drought stress could have important implications for accelerating the process of pyramiding of favourable genes into adapted genotypes and on future marker-assisted breeding for drought prone areas.