Association mapping and resistant alleles' analysis for japonica rice blast resistance

摘要

Rice blast is one of the major fungal diseases that badly reduce rice production in China and worldwide. Association mapping for blast resistance was performed on 226 japonica rice cultivars with 118 pairs of SSR markers. The blast resistance was evaluated by inoculating with two isolates, DB22 and DB77, at the tillering stage in 2013 and 2014, separately. A total of 31 associations with 17 different SSRs were significantly (P < 0.05) associated with blast resistance based on the mixed linear model (MLM), of which nine markers could be detected in both 2013 and 2014, including two markers that were simultaneously associated with the two isolates. Five of the nine stable markers were consistent with the genome regions identified by linkage mapping in previous reports. Phenotypic effects of each allele of the nine stable markers were compared, and 18 favourable alleles were identified. Five elite parental combinations were designed for improving blast resistance in rice. Our results demonstrate that association mapping can complement and enhance previous QTL information for marker-assisted selection and breeding by design.