A trait must genetically correlate with fitness in order to evolve, however, theory suggests that strong directional selection should erode additive genetic variance (Va) in fitness and limit future evolutionary potential. Sexual antagonism and temporal fluctuations in selection are mechanisms that could maintain Va in fitness. Maternal genetic effects could be an additional source of adaptive genetic variation. I used ‘animal models’ to examine a long-term population of red squirrels to determine 1) if either sexual antagonism or temporal fluctuations in selection were maintaining direct Va in fitness or 2) if maternal genetic effects were a source of indirect Va in fitness. While there were environmental trade-offs on juvenile survival, neither sexual antagonism nor temporal fluctuations in selection maintained Va in fitness. Maternal genetic effects on fitness were significant and provide the Va in fitness needed for rapid microevolution. This is the first instance of maternal genetic effects demonstrated as the only genetic variance available for microevolution. / Northern Scientific Training Program, the Arctic Institute of North America, American Society of Mammologists, Queen Elizabeth II Graduate Scholarship in Science and Technology, NSERC Discovery (to Andrew McAdam), NSF (to Andrew McAdam)

Submitted by Jadson Francisco de Jesus SILVA (jadson@uefs.br) on 2018-02-22T21:50:40Z No. of bitstreams: 1 PREDI??O DE PAR?METROS GEN?TICOS E INCREMENTO DA QUALIDADE DEFINITIVO.pdf: 1627949 bytes, checksum: 31c34b863f924737f87f81fa9f625403 (MD5) / Made available in DSpace on 2018-02-22T21:50:40Z (GMT). No. of bitstreams: 1 PREDI??O DE PAR?METROS GEN?TICOS E INCREMENTO DA QUALIDADE DEFINITIVO.pdf: 1627949 bytes, checksum: 31c34b863f924737f87f81fa9f625403 (MD5) Previous issue date: 2017-03-17 / The study aimed to estimate genetic parameters and genetic variability, as well as to determine the correlations among fruit variables associated with production and pulp quality attributes in pumpkin progenies. In 2013, the parameters and prediction of progeny gains allowed the ranking of the best individuals in 10 progenies from self pollination. In 2015 the divergence was determined, selecting genotypes for qualitative and quantitative characteristics, and studying the correlations among fruit variables associated with production and pulp quality attributes in 11 evaluated genotypes. In 2013, the REML/BLUP analysis allowed the ranking considering all variables evaluated indicating the individuals 10/1/1, 10/2/12 and 6/1/3 as more promising, being the first two of ?piriform? format, and the third of "moranga" format. In 2015, it was found great variability in the progenies evaluated and similarity among progenies C. moschata 1, C. moschata 3, C. moschata 4 and C. moschata 8. The promising progenies for fruit mass and ?-carotene were C. Moschata 4 and C. moschata 7 for advances aiming to increase of production and the nutritional characteristics of the fruit. Estimates of carotenoid contents generated by the Hue angle are only valid for contrasting genotypes due to the grouping of genotypes with carotenoid content four times higher than ?Jacarezinho? cultivar. The variables explained 98% of the variation in the basic variable in the path analysis and four variables can be used for direct selection aiming to increase of fruit mass. / O estudo objetivou obter estimativas de par?metros gen?ticos e de variabilidade gen?tica, bem como determinar as correla??es entre vari?veis do fruto associadas ? produ??o e atributos de qualidade da polpa em prog?nies de ab?bora. Em 2013, os par?metros e a predi??o de ganhos gen?ticos permitiram o ranqueamento dos melhores indiv?duos em 10 prog?nies provenientes de autofecunda??es. Em 2015 determinou-se a diverg?ncia, sendo feita a sele??o de gen?tipos para caracteres qualitativos e quantitativos, al?m de estudar as correla??es entre vari?veis do fruto associadas ? produ??o e atributos de qualidade da polpa em 11 gen?tipos avaliados. Em 2013, a an?lise via REML/BLUP possibilitou o ranqueamento considerando todas as vari?veis avaliadas indicando os indiv?duos 10/1/1, 10/2/12 e 6/1/3 como mais promissores, sendo os dois primeiros de formato ?piriforme? e o terceiro de formato ?moranga?. Em 2015, constatou-se grande variabilidade nas prog?nies avaliadas e similaridade entre as prog?nies C. moschata 1, C. moschata 3, C. moschata 4 e C. moschata 8. As prog?nies promissoras para massa do fruto e ?-caroteno foram C. moschata 4 e C. moschata 7 para avan?os visando aumento da produ??o e das caracter?sticas nutricionais do fruto. As estimativas dos teores de carotenoides geradas pelo ?ngulo Hue somente s?o v?lidas para gen?tipos contrastantes devido ao agrupamento de gen?tipos com teores de carotenoides quatro vezes maiores em rela??o a cultivar Jacarezinho. As vari?veis explicaram 98% da varia??o ocorrida na vari?vel b?sica na an?lise de trilha e quatro vari?veis podem ser utilizadas para a sele??o direta visando aumento da massa do fruto.

<p>In this thesis, quantitative genetic approaches, common-garden experiments, and field studies were combined to examine patterns of population differentiation and the genetic architecture of characters of putative adaptive significance in the widely distributed perennial herb Lythrum salicaria. In this work, I (1) documented patterns of population differentiation in phenology, life-history, and morphology along latitudinal gradients at different geographical scales, (2) investigated the genetic architecture of phenology, flower morphology, and inflorescence size, and (3) combined estimates of phenotypic selection in the field with information on the genetic variance-covariance matrix (G) to examine potential constraints to adaptive evolution. </p><p>A common-garden experiment demonstrated latitudinal variation in life-history, and phenology of growth and reproduction among L. salicaria populations sampled across Sweden. Flower morphology varied significantly among populations, but was, with the exception of calyx length, not related to latitude of origin. A second experiment, which included two Swedish, two Dutch, and two Spanish populations, indicated that the latitudinal gradient in reproductive and vegetative phenology might extend throughout Europe.</p><p>A quantitative-genetic study of two Swedish populations revealed significant additive genetic variation for all phenological and morphological traits investigated. The G matrices of the populations differed significantly according to common principal component analysis, and genetic correlations within the study populations did not strictly correspond to trait correlations observed among populations.</p><p>In a field study, I detected directional selection through female function for larger inflorescences in two consecutive years. Relative fitness increased disproportionately with inflorescence size in the year when supplemental hand-pollination indicated that pollen limitation was severe. Genetic correlations with inflorescence size considerably influenced predicted response to selection in other characters.</p><p>Taken together, the results suggest that among-population differences in phenology and life-history in L. salicaria have evolved in response to latitudinal variation in length of the growing season. They demonstrate that the evolutionary potential of local populations may be considerable. The genetic covariance structure substantially influences predicted short-term evolutionary trajectories. However, the weak correspondence between genetic correlations documented within populations and trait correlations among populations, suggest that the G matrix has not imposed strict constraints on patterns of among-population differentiation.</p>

In this thesis, quantitative genetic approaches, common-garden experiments, and field studies were combined to examine patterns of population differentiation and the genetic architecture of characters of putative adaptive significance in the widely distributed perennial herb Lythrum salicaria. In this work, I (1) documented patterns of population differentiation in phenology, life-history, and morphology along latitudinal gradients at different geographical scales, (2) investigated the genetic architecture of phenology, flower morphology, and inflorescence size, and (3) combined estimates of phenotypic selection in the field with information on the genetic variance-covariance matrix (G) to examine potential constraints to adaptive evolution. A common-garden experiment demonstrated latitudinal variation in life-history, and phenology of growth and reproduction among L. salicaria populations sampled across Sweden. Flower morphology varied significantly among populations, but was, with the exception of calyx length, not related to latitude of origin. A second experiment, which included two Swedish, two Dutch, and two Spanish populations, indicated that the latitudinal gradient in reproductive and vegetative phenology might extend throughout Europe. A quantitative-genetic study of two Swedish populations revealed significant additive genetic variation for all phenological and morphological traits investigated. The G matrices of the populations differed significantly according to common principal component analysis, and genetic correlations within the study populations did not strictly correspond to trait correlations observed among populations. In a field study, I detected directional selection through female function for larger inflorescences in two consecutive years. Relative fitness increased disproportionately with inflorescence size in the year when supplemental hand-pollination indicated that pollen limitation was severe. Genetic correlations with inflorescence size considerably influenced predicted response to selection in other characters. Taken together, the results suggest that among-population differences in phenology and life-history in L. salicaria have evolved in response to latitudinal variation in length of the growing season. They demonstrate that the evolutionary potential of local populations may be considerable. The genetic covariance structure substantially influences predicted short-term evolutionary trajectories. However, the weak correspondence between genetic correlations documented within populations and trait correlations among populations, suggest that the G matrix has not imposed strict constraints on patterns of among-population differentiation.

In most breeding programmes breeders use phenotypic data obtained in breeding trials to rank the performance of the parents or progeny on pre-selected performance criteria. Through this ranking the best candidates are identified and selected for breeding or production purposes. Best Linear Unbiased Prediction (BLUP), is an efficient selection method to use, combining information into a single index. Unbalanced or messy data is frequently found in tree breeding trial data. Trial individuals are related and a degree of correlation is expected between individuals over sites, which can lead to collinearity in the data which may lead to instability in certain selection models. A high degree of collinearity may cause problems and adversely affect the prediction of the breeding values in a BLUP selection index. Simulation studies have highlighted that instability is a concern and needs to be investigated in experimental data. The occurrence of instability, relating to collinearity, in BLUP of tree breeding data and possible methods to deal with it were investigated in this study. Case study data from 39 forestry breeding trials (three generations) of Eucalyptus grandis and 20 trials of Pinus patula (two generations) were used. A series of BLUP predictions (rankings) using three selection traits and 10 economic weighting sets were made. Backward and forward prediction models with three different matrix inversion techniques (singular value decomposition, Gaussian elimination - partial and full pivoting) and an adapted ridge regression technique were used in calculating BLUP indices. A Delphi and Clipper version of the same BLUP programme which run with different computational numerical precision were used and compared. Predicted breeding values (forward prediction) were determined in the F1 and F2 E. grandis trials and F1 P. patula trials and realised breeding performance (backward prediction) was determined in the F2 and F3 E. grandis trials and F2 P. patula trials. The accuracy (correlation between the predicted breeding values and realised breeding performance) was estimated in order to assess the efficiency of the predictions and evaluate the different matrix inversion methods. The magnitude of the accuracy (correlations) was found to mostly be of acceptable magnitude when compared to the heritability of the compound weighted trait in the F1F2 E. grandis scenarios. Realised genetic gains were also calculated for each method used. Instability was observed in both E. grandis and P. patula breeding data in the study, and this may cause a significant loss in realised genetic gains. Instability can be identified by examining the matrix calculated from the product of the phenotypic covariance matrix with its inverse, for deviations from the expected identity pattern. Results of this study indicate that it may not always be optimal to use a higher numerical precision programme when there is collinearity in the data and instability in the matrix calculations. In some cases, where there is a large amount of collinearity, the use of a higher precision programme for BLUP calculations can significantly increase or decrease the accuracy of the rankings. The different matrix inversion techniques particularly SVD and adapted ridge regression did not perform much better than the full pivoting technique. The study found that it is beneficial to use the full pivoting Gaussian elimination matrix inversion technique in preference to the partial pivoting Gaussian elimination matrix inversion technique for both high and lower numerical precision programmes. / Thesis (PhD)--University of Pretoria, 2013. / gm2014 / Genetics / unrestricted