USING ASSOCIATION ANALYSIS AND GENOMIC SELECTION TO IMPROVE FUSARIUM HEAD BLIGHT RESISTANCE IN SOFT RED WINTER WHEAT

摘要

With new marker platforms continuing to become available for crop species and the cost of genotyping reducing, breeders are now able to use this technology for crop improvement. Association analysis aims to identify marker trait relationships and is based on linkage disequilibrium between the quantitative trait loci (QTL) and markers: these associations can be used in marker-assisted selection (MAS). However, most quantitative traits are controlled by many small effect QTL making MAS ineffective. Analternative approach is to use genomic selection (GS) to estimate all marker effects simultaneously and determine the breeding value of the individuals. The first objective of this research was to identify, locate, and determine the magnitude of QTL effects for Fusarium head blight (FHB) resistance. The second objective was to determine the accuracy of GS models for predicting FHB resistance. We used a population of 470 elite breeding lines genotyped using genotyping-by-sequencing. Lines were phenotypedfor FHB index for two years. The heritability of FHB Index was 0.59. We identified four significant QTL with R~2 values ranging from 2.6 to 2.8% and allele effects ranging from 1.07 to 1.76%. No QTLs were found in common between FHB and heading date (HD) or height. The relative efficiencies of GS models for FHB prediction ranged from 0.22 to 0.5. Based on these results we believe these technologies will be useful for improving FHB resistance in this soft red winter wheat population.