Table_2_Genome-Wide Association Mapping of Seedling Biomass and Root Traits Under Different Water Conditions in Wheat.xlsx

Drought is a major threat to global wheat production. In this study, an association panel containing 200 Chinese wheat germplasms was used for genome-wide association studies (GWASs) of genetic loci associated with eight root and seedling biomass traits under normal water and osmotic stress conditions. The following traits were investigated in wheat seedlings at the four-leaf stage: root length (RL), root number (RN), root fresh weight (RFW), root dry weight (RDW), shoot fresh weight (SFW), shoot dry weight (SDW), total fresh weight (TFW), and total dry weight (TDW). A total of 323 and 286 SNPs were detected under two water environments, respectively. Some of these SNPs were near known loci for root traits. Eleven SNPs on chromosomes 1B, 2B, 4B, and 2D had pleiotropic effects on multiple traits under different water conditions. Further analysis indicated that several genes located inside the 4 Mb LD block on each side of these 11 SNPs were known to be associated with plant growth and development and thus may be candidate genes for these loci. Results from this study increased our understanding of the genetic architecture of root and seedling biomass traits under different water conditions and will facilitate the development of varieties with better drought tolerance.

干旱是全球小麦生产面临的重大非生物胁迫威胁。本研究以包含200份中国小麦种质资源的关联作图群体为材料，针对正常水分与渗透胁迫环境下与8项根系及幼苗生物量性状相关的遗传位点开展全基因组关联分析（Genome-Wide Association Studies, GWASs）。本研究在四叶龄小麦幼苗中调查了以下8项性状：根长（root length, RL）、根数（root number, RN）、根鲜重（root fresh weight, RFW）、根干重（root dry weight, RDW）、地上部鲜重（shoot fresh weight, SFW）、地上部干重（shoot dry weight, SDW）、总鲜重（total fresh weight, TFW）以及总干重（total dry weight, TDW）。在两种水分环境下分别检测到323个和286个单核苷酸多态性位点（Single Nucleotide Polymorphism, SNP），其中部分位点毗邻已报道的根系性状相关遗传位点。位于1B、2B、4B与2D染色体上的11个SNP位点在不同水分条件下对多个性状表现出多效性作用。进一步分析表明，坐落于这11个SNP位点两侧各4 Mb的连锁不平衡（Linkage Disequilibrium, LD）区块内的数个基因已被证实与植物生长发育密切相关，因此可作为上述遗传位点的候选基因。本研究结果深化了学界对不同水分环境下根系与幼苗生物量性状遗传架构的认知，同时将助力抗旱性更优异的小麦品种培育工作。