Submitted by Nathália Faria da Silva (nathaliafsilva.ufv@gmail.com) on 2017-07-11T10:51:51Z No. of bitstreams: 1 texto completo.pdf: 993006 bytes, checksum: d6a0e872e24eb36ce9bebd55844acea7 (MD5) / Made available in DSpace on 2017-07-11T10:51:51Z (GMT). No. of bitstreams: 1 texto completo.pdf: 993006 bytes, checksum: d6a0e872e24eb36ce9bebd55844acea7 (MD5) Previous issue date: 2003-02-07 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Os genótipos do gene PSS foram caracterizados para 596 suínos procedentes de um cruzamento F 2 entre fêmeas comerciais e suínos nativos brasileiros, por meio da técnica de PCR-RFLP. As características de carcaça, desempenho e qualidade da carne foram avaliadas. Entre os 596 animais analisados, 493 (82,72%) foram caracterizados como NN e 103 (17,28%), como Nn. Animais Nn, quando comparados com animais NN, apresentaram, para as características de carcaça, maiores (P<0,05) valores de peso da banda direita (27,30±2,67 vs. 26,85±2,67), peso da banda esquerda (27,21±2,60 vs. 26,74±2,60), profundidade do lombo (45,48±4,34 vs. 43,43±4,34) e área de olho de lombo (28,14±2,74 vs. 26,09±2,74) e menores espessuras de toucinho na região da copa (39,08±5,43 vs. 40,86±5,43), espessuras de toucinho entre a última e a penúltima vértebra lombar (27,30±5,94 vs. 28,92±5,94) e espessuras de toucinho após a última costela, a 6,5cm da linha dorso-lombar (15,51±3,74 vs. 17,24±3,74), o que indica maior peso ao abate, menor deposição de gordura na carcaça e maior deposição de carne na carcaça, para animais portadores do alelo n. Animais Nn, quando comparados com animais NN, apresentaram, para cortes, maiores (P<0,05) valores de peso da banda direita resfriada (26,99±2,90 vs. 26,45±2,90), peso do pernil (7,40±0,82 vs. 7,29±0,82), peso do pernil sem pele e sem gordura (5,23±0,60 vs. 4,96±0,60), peso da copa sem ivpele e sem gordura (1,75±0,27 vs. 1,68±0,27), peso da paleta (5,00±0,61 vs. 4,88±0,61), peso da paleta sem pele e sem gordura (2,87±0,39 vs. 2,68±0,39), peso do lombo (1,11±0,18 vs. 1,01±0,18), peso da cabeça (1,56±0,21 vs. 1,51±0,21) e peso do filezinho (0,24±0,04 vs. 0,22±0,04), o que indica maiores rendimentos de cortes para animais portadores do alelo n, confirmando os resultados de características de carcaça, e menores valores para espessura do bacon (23,68±6,63 vs. 25,38±6,63), confirmando a menor deposição de gordura na carcaça. Animais Nn, quando comparados com animais NN, apresentaram menores (P<0,05) valores para a característica de desempenho peso aos 105 dias (36,01±6,28 vs. 36,82±6,28), indicando menor taxa de crescimento para animais portadores do alelo n, nesta idade. Os animais dos dois genótipos (NN e Nn, respectivamente) não diferiram (P>0,05) para pH 24 horas após o abate (5,71±0,15 vs. 5,70±0,15), porcentagem de gordura intramuscular (1,55±0,64 vs. 1,65±0,64), força de cisalhamento (5551,60±871,95 vs. 5506,60±871,95), luminosidade (44,96±2,02 vs. 45,01±2,02), índice de vermelho (0,64±0,60 vs. 0,79±0,60), índice de amarelo (6,62±0,55 vs. 6,65±0,55), tonalidade de cor (84,28±5,56 vs. 83,41±5,56) e índice de saturação (6,68±0,52 vs. 6,73±0,52). No entanto, animais Nn, quando comparados com animais NN, apresentaram (P<0,05) menores valores de pH 45 minutos após o abate (6,41±0,26 vs. 6,51±0,26) e maiores valores para perda d água por gotejamento (3,92±1,68 vs. 3,06±1,68), cozimento (33,29±2,54 vs. 32,50±2,54) e perda de água total (35,67±2,67 vs. 34,01±2,67). Os resultados obtidos mostram que mesmo animais originados de cruzamento divergente, portadores do gene PSS, apresentaram maior rendimento de carne magra, maior rendimento de cortes, menor deposição de gordura na carcaça e carne de qualidade inferior. / The PSS gene genotypes of 596 F 2 pigs produced by initial mating of Brazilian commercial sows and native boars were characterized by the PCR-RFLP technique and their carcass, performance and meat quality traits were evaluated. Among the 596 analyzed animals, 493 animals (82.72%) were characterized as NN and 103 animals (17.28%) as Nn. Nn animals, compared to NN animals, presented, for the carcass traits, higher (P<0.05) values for right half carcass weight (27.30±2.67 vs. 26.85±2.67), left half carcass weight (27.21±2.60 vs. 26.74±2.60), loin depth (45.48±4.34 vs. 43.43±4.34) and loin eye area (28.14±2.74 vs. 26.09±2.74), and lower values for shoulder backfat thickness (39.08±5.43 vs. 40.86±5.43), backfat thickness between last and last but one lombar vertebrae (27.30±5.94 vs. 28.92±5.94), backfat thickness after last rib, at 6.5 cm from the midline (15.51±3.74 vs. 17.24±3.74), indicating higher slaughter weight, lower carcass fat deposition and higher carcass lean content for animals carrying the n allele. Nn animals, compared to NN animals, presented, for carcass cuts yields, higher (P<0.05) values for cold right half carcass weight (26.99±2.90 vs. 26.45±2.90), ham weight (7.40±0.82 vs. 7.29±0.82), skinless and fatless ham weight (5.23±0.60 vs. 4.96±0.60), skinless and fatless boston shoulder weight (1.75±0.27 vs. 1.68±0.27), picnic shoulder weight vi(5.00±0.61 vs. 4.88±0.61), skinless and fatless picnic shoulder weight (2.87±0.39 vs. 2.68±0.39), loin weight (1.11±0.18 vs. 1.01±0.18), head weight (1.56±0.21 vs. 1.51±0.21) and sirloin weight (0.24±0.04 vs. 0.22±0.04), indicating greater cuts yields for n allele carrying animals, confirming the carcass traits results, and lower values for bacon depth (23.68±6.63 vs. 25.38±6.63), confirming lower carcass fat deposition. Nn animals, compared to NN animals, presented lower (P<0.05) values for the performance trait weight at 105 days of age (36.01±6.28 vs. 36.82±6.28), indicating a lower growth rate for animals carrying the n allele, at this age. Both genotypes animals (NN and Nn, respectively) did not differ (P>0.05) for pH at 24 hours after slaughter (5.71±0.15 vs. 5.70±0.15), marbling (1.55±0.64 vs. 1.65±0.64), shear force (5551.60±871.95 vs. 5506.60±871.95), lightness (44.96±2.02 vs. 45.01±2.02), redness (0.64±0.60 vs. 0.79±0.60), yellowness (6.62±0.55 vs. 6.65±0.55), hue (84.28±5.56 vs. 83.41±5.56) and chroma (6.68±0.52 vs. 6.73±0.52). However, Nn animals, compared to NN animals, presented lower (P<0.05) pH at 45 minutes after slaughter (6.41±0.26 vs. 6.51±0.26), and higher drip (3.92±1.68 vs. 3.06±1.68), cooking (33.29±2.54 vs. 32.50±2.54) and total (35.67±2.67 vs. 34.01±2.67) water losses. These results show that animals carrying the PSS gene, even those from divergent crossing, generate leaner carcasses, with higher cutting yields and lean content. On the other hand, they produce meat of inferior quality.

La sélection génomique, qui a révolutionné la sélection génétique des bovins laitiers notamment, est désormais envisagée dans d’autres espèces comme l’espèce caprine. La clé du succès de la sélection génomique réside dans la précision des évaluations génomiques. Chez les caprins laitiers français, le gain de précision attendu avec la sélection génomique était un des questionnements de la filière en raison de la petite taille de la population de référence disponible (825 mâles et 1945 femelles génotypés sur une puce SNP 50K). Le but de cette étude est d’évaluer comment augmenter la précision des évaluations génomiques dans l’espèce caprine. Une étude de la structure génétique de la population de référence caprine constituée d’animaux de races Saanen et Alpine, a permis de montrer que la population de référence choisie est représentative de la population élevée sur le territoire français. En revanche, les faibles niveaux de déséquilibre de liaison (0,17 entre deux SNP consécutifs) de consanguinité et de parenté au sein de la population, similaires à ceux trouvés en ovins Lacaune, ne sont pas idéaux pour obtenir une bonne précision des évaluations génomiques. De plus, malgré l’origine commune des races Alpine et Saanen, leurs structures génétiques suggèrent qu’elles se distinguent clairement d’un point de vue génétique. Les méthodes génomiques (GBLUP ou Bayésiennes) « two-step », basées sur des performances pré-corrigées (DYD, EBV dérégressées) n’ont pas permis une amélioration significative des précisions des évaluations génomiques pour les caractères évalués en routine (caractères de production, de morphologie et de comptages de cellules somatiques) chez les caprins laitiers. La prise en compte des phénotypes des mâles non génotypés permet d’augmenter les précisions des évaluations de 3 à 47% selon le caractère. L’ajout des génotypes de femelles issues d’un dispositif de détection de QTL améliore également les précisions (de 2 à 14%) que ce soit pour les évaluations two steps ou les évaluations basées sur les performances propres des femelles (single step). Les précisions sont augmentées de 10 à 74% avec les évaluations single step comparées aux évaluations two steps, ce qui permet d’atteindre des précisions supérieures à celles obtenues sur ascendance. Les précisions obtenues avec les évaluations génomiques multiraciales, bicaractères et uniraciales sont similaires même si la précision des valeurs génomiques estimées des candidats à la sélection est plus élevée avec les évaluations multiraciales. La sélection génomique est donc envisageable chez les caprins laitiers français à l’aide d’un modèle génomique multiracial single step. Les précisions peuvent être légèrement augmentées par l’inclusion de gènes majeurs tels que celui de la caséine αs1 notamment à l’aide d’un modèle « gene content » pour prédire le génotype des animaux non génotypés. / Genomic selection which is revolutionizing genetic selection in dairy cattle has been tested in several species like dairy goat. Key point in genomic selection is accuracy of genomic evaluation. In French dairy goats, gain in accuracy using genomic selection was questioning due to the small size of the reference population (825 males and 1 945 females genotyped). The aim of this study was to investigate how to reach adequate genomic evaluation accuracy in French dairy goat population. The study of reference population structure (Alpine and Saanen breeds) showed that reference population is similar to the whole population of French dairy goats. But the weak level of linkage disequilibrium (0.17 between two consecutive SNP), inbreeding and relationship between reference and candidate population were not ideal to maximize genomic evaluation accuracy. Despite their common origin, genetic structure of Alpine and Saanen breeds suggested that they were genetically distant. Two steps genomic evaluation (GBLUP, Bayesian) based on performances corrected for fixed effect (DYD, deregressed EBV) did not improve genetic evaluation accuracy compared to classical evaluations for milk production traits, udder type traits and somatic cells score classically selected in French dairy goat. Taking into account phenotypes of ungenotyped sires increased genomic evaluation from 3 to 47% depending on the trait considered. Adding female genotypes also improved genomic evaluation accuracies from 2 to 4% depending on the method (two steps or single step) and on the trait. When using gemomic evaluation directly based on female performances (single step), accuracy of genomic evaluation reach the level obtained from ascendance in classic evaluation which was not the case using two steps evaluations. Genomic evaluation accuracies were similar when using multiple-trait model, multi-breed or single breed evaluation. But accuracies derived from prediction error variances were better when using multi-breed genomic evaluations. Genomic selection is feasible in French dairy goats using single step multi-breed genomic evaluations. Accuracies could be slightly improved integrating major gene as αs1 casein especially when using « gene content » approach to predict genotypes of ungenotyped animals.

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.

The latter part of the reproductive growth phase in chickpea (<i>Cicer arietinum</i> L.) often coincides with declining temperature and wet conditions in western Canada, in sharp contrast to many other growing environments. This exacerbates the indeterminate nature of the crop, leading to excessive canopy development, and subsequently resulting in delayed maturity. The objectives of this study were to: i) determine the genetic relationships of short internode, double podding and early flowering traits with earliness of crop maturity; ii) determine the genetic control of major earliness traits in chickpea; iii) assess the patterns of post-flowering dry matter accumulation and partitioning to reproductive parts as related to earliness. <p>The results showed that double podding significantly reduced the number of days taken to maturity, under the conditions where this trait was sufficiently expressed. The best double podding genotypes, i.e. those with 1535% of the podded nodes bearing double pods, were about one week earlier than their single podding counterparts and standard checks. A physiological study revealed that the double podding parental genotype 272-2 partitioned a relatively greater proportion (about 58%) of the total dry matter to pods compared to 4254% in the single podding genotypes. Double podding increased the total number of pods set, and thus the increased demand for assimilates may have precluded further production of stems and leaves, resulting in an earlier transition of reproductive growth to physiological maturity. Days to flowering was positively associated with days to maturity, and partial path analysis revealed that days to flowering contributed to days to maturity indirectly via days to first pod maturity. Days to flowering explained 32% of the variation in days to first pod maturity. However, the short internode trait had an undesirable effect, in that all the short internode segregants were too late to mature. <p>Genetic studies revealed that days to flowering was determined by two major genes plus polygenes in chickpea in the short-season temperate environment of western Canada. The two major genes control over 65% of the phenotypic variation. Also, the additive component of genetic variance was significant for days to first podding, days to first pod maturity, reproductive period, and days to maturity; which is desirable for development of superior inbred cultivars of chickpea. These key phenological traits are interrelated but could be manipulated separately in the breeding process. Additional gain in earliness of crop maturity may be achieved through combined selection for these traits.

The latter part of the reproductive growth phase in chickpea (<i>Cicer arietinum</i> L.) often coincides with declining temperature and wet conditions in western Canada, in sharp contrast to many other growing environments. This exacerbates the indeterminate nature of the crop, leading to excessive canopy development, and subsequently resulting in delayed maturity. The objectives of this study were to: i) determine the genetic relationships of short internode, double podding and early flowering traits with earliness of crop maturity; ii) determine the genetic control of major earliness traits in chickpea; iii) assess the patterns of post-flowering dry matter accumulation and partitioning to reproductive parts as related to earliness. <p>The results showed that double podding significantly reduced the number of days taken to maturity, under the conditions where this trait was sufficiently expressed. The best double podding genotypes, i.e. those with 1535% of the podded nodes bearing double pods, were about one week earlier than their single podding counterparts and standard checks. A physiological study revealed that the double podding parental genotype 272-2 partitioned a relatively greater proportion (about 58%) of the total dry matter to pods compared to 4254% in the single podding genotypes. Double podding increased the total number of pods set, and thus the increased demand for assimilates may have precluded further production of stems and leaves, resulting in an earlier transition of reproductive growth to physiological maturity. Days to flowering was positively associated with days to maturity, and partial path analysis revealed that days to flowering contributed to days to maturity indirectly via days to first pod maturity. Days to flowering explained 32% of the variation in days to first pod maturity. However, the short internode trait had an undesirable effect, in that all the short internode segregants were too late to mature. <p>Genetic studies revealed that days to flowering was determined by two major genes plus polygenes in chickpea in the short-season temperate environment of western Canada. The two major genes control over 65% of the phenotypic variation. Also, the additive component of genetic variance was significant for days to first podding, days to first pod maturity, reproductive period, and days to maturity; which is desirable for development of superior inbred cultivars of chickpea. These key phenological traits are interrelated but could be manipulated separately in the breeding process. Additional gain in earliness of crop maturity may be achieved through combined selection for these traits.