Genetic variance, transgressive segregation, and genomic selection prediction accuracy for Fusarium head blight resistance in advanced multi-parent barley breeding populations

Abstract

The contemporary era of molecular breeding includes predicting breeding values based on allelic value estimations with genome-wide markers. The overarching objective of this thesis is to assess the potential use of genomic markers in predicting genetic variance, transgressive segregation, and breeding values within barley breeding populations in the context of Fusarium head blight (FHB) resistance. Chapter One investigates prediction of genetic variance and transgressive segregation using measures of phenotypic and genotypic parental dissimilarity. To a limited extent, phenotypic dissimilarity could predict transgressive segregation and genetic variance while genetic dissimilarity using a subset of FHB-associated single nucleotide polymorphism markers could predict genetic variance in both populations. Homogeneity of genomic selection prediction accuracy among families for FHB severity and deoxynivalenol concentration was examined in Chapter Two. Accuracy between predicted and observed values for both traits varied among families. Potential factors for limited ability to predict individual family performance are discussed.