西葫芦主要农艺性状的全基因组关联分析OA

[Objective]To explore single nucleotide polymorphism(SNP)loci and candidate genes associated with key agronomic traits in zucchini(Cucurbita pepo L.),providing molecular markers for breeding.[Method]A total of 89 zucchini accessions were used as experimental materials.Agronomic traits,including fruit length,fruit skin color,stem color,fruit speckling,and vine length type,were investigated.Genetic relationships were analyzed based on linkage disequilibrium(LD)and popula-tion structure.The optimal model was selected for genome-wide association analysis(GWAS)for these traits.[Result]Significant phenotypic variation was observed among the zucchini accessions,with a coefficient of variation of 18.42%for fruit length.The diversity indices for vine length type,fruit skin color,stem color,and fruit speckling were 1.051,1.843,0.646,and 0.992,respec-tively.Based on 4.15 million SNP variants,the 89 accessions were divided into two subpopulations,with an average kinship coefficient of-0.019 and an LD decay distance of 15.636 kb.GWAS detected 174 significant loci associated with major agronomic traits.These loci were distributed across chromosomes 1,3,4,9,10,19,and 20,spanning a 1.71 Mb genomic region.Annotation analysis screened 24 candidate genes related to these important traits.Among them,two candidate genes(Cp4.1LG04g08240 and Cp4.1LG04g08270)were associated with fruit length,two candidate genes(Cp4.1LG04g12540 and Cp4.1LG04g12480)for skin color,and one candidate gene(Cp4.1LG15g03420)for stem color.Additionally,16 candidate genes were identified for fruit peel spots,including Cp4.1LG10g03790,which is involved in the chlorophyll metabolism pathway.Three genes(Cp4.1LG01g14740,Cp4.1LG01g14770,and Cp4.1LG01g14800)were identified as candi-dates associated with stem length.