Quantitative trait loci responsible for sharp eyespot resistance in common wheat CI12633

Sharp eyespot is a major fungal disease of wheat caused by Rhizoctonia cerealis in cool and humid environments worldwide. In this study, 224 single seed descent derived F(13), F(14) and F(15) recombinant inbred lines (RILs) from the cross between CI12633 (a resistant cultivar) and Yangmai 9 (a susceptible cultivar) were assessed for sharp eyespot resistance (R.cerealis isolate R0301) in field and greenhouse conditions in three growing seasons. Different agronomic characteristics were also evaluated in the field with no disease infection. All the lines were genotyped with the Illumina iSelect 90 K SNP wheat chip and 101 SSR markers. Sharp eyespot resistance was significantly negatively correlated with heading date and tiller angle, and significantly positively correlated with the diameter of the basal first internode and second internode. Five QTL with a likelihood of odds ratio score of higher than 3.0 were detected on chromosomes 2BS, 4BS, 5AL and 5BS, respectively. These identified QTL may be used in future wheat breeding programs through marker assisted selection for developing sharp eyespot resistant cultivars.