Genome-wide association analysis of Fusarium crown rot resistance in Chinese wheat landraces

Abstract

A novel locus for Fusarium crown rot (FCR) resistance was identified on chromosome 1B at 641.36-645.13Mb using GWAS and could averagely increase 39.66% of FCR resistance in a biparental population. Fusarium crown rot can cause considerable yield losses. Developing and growing resistance cultivars is one of the most effective approaches for controlling this disease. In this study, 361 Chinese wheat landraces were evaluated for FCR resistance, and 27 with the disease index lower than 30.00 showed potential in wheat breeding programs. Using a genome-wide association study approach, putative quantitative trait loci (QTL) for FCR resistance was identified. A total of 21 putative loci on chromosomes 1A, 1B, 2B, 2D, 3B, 3D, 4B, 5A, 5B, 7A, and 7B were significantly associated with FCR resistance. Among these, a major locus Qfcr.sicau.1B-4 was consistently identified among all the trials on chromosome 1B with the physical regions from 641.36 to 645.13Mb. A polymorphism kompetitive allele-specific polymerase (KASP) marker was developed and used to validate its effect in an F2:3 population consisting of 136 lines. The results showed the presence of this resistance allele could explain up to 39.66% of phenotypic variance compared to its counterparts. In addition, quantitative real-time polymerase chain reaction showed that two candidate genes of Qfcr.sicau.1B-4 were differently expressed after inoculation. Our study provided useful information for improving FCR resistance in wheat.