小麦株高全基因组关联分析及候选位点验证OA

Plant height(PH)is an important agronomic trait affecting lodging resistance and yield in wheat.To dissect the genetic basis of PH and identify stable loci,we analyzed a natural population of 339 wheat accessions from the Huang-Huai wheat region using PH phenotypes collected across nine environments and genotypes obtained with a 21K single nucleotide polymorphism(SNP)array.Ge-nome-wide association study(GWAS)was conducted using a mixed linear model(MLM).Linkage dis-equilibrium(LD)and haplotype analyses were performed for the key associated interval,and the asso-ciation was further validated in a natural population of 327 accessions genotyped with a 660K SNP ar-ray.Candidate genes within the target interval were annotated and prioritized.In total,66 stable QTLs significantly associated with PH were identified.A novel major and stable QTL,QPh.nwafu-6D,was detected on chromosome 6D(490.34-492.42 Mb)and was consistently detected in eight en-vironments,explaining 8.23％of the phenotypic variance on average.The interval was divided into two LD blocks.In Block2,three haplotypes were identified,and the favorable haplotype Block2_Hap1(frequency 84.1％)showed significantly reduced PH compared with other haplotypes and was significantly associated with higher thousand-kernel weight in multiple environments.In the valida-tion population,accessions carrying the Block2_Hap1 genotype at the core SNP marker SNP_Chr6D_492211566 exhibited significantly lower PH than those with the Block2_Hap2 genotype(P＜0.001).Eight candidate genes were further prioritized in this interval,mainly involved in kinase signaling,transcriptional regulation,ubiquitin-mediated protein degradation,and hormone responses.