DataSheet_1_Genome-wide association study of yield-related traits in common wheat (Triticum aestivum L.) under normal and drought treatment conditions.docx

The primary goal of modern wheat breeding is to develop new high-yielding and widely adaptable varieties. We analyzed four yield-related agronomic traits in 502 wheat accessions under normal conditions (NC) and drought treatment (DT) conditions over three years. The genome-wide association analysis identified 51 yield-related and nine drought-resistance-related QTL, including 13 for the thousand-grain weight (TGW), 30 for grain length (GL), three for grain width (GW), five for spike length (SL) and nine for stress tolerance index (STI) QTL in wheat. These QTL, containing 72 single nucleotide polymorphisms (SNPs), explained 2.23 – 7.35% of the phenotypic variation across multiple environments. Eight stable SNPs on chromosomes 2A, 2D, 3B, 4A, 5B, 5D, and 7D were associated with phenotypic stability under NC and DT conditions. Two of these stable SNPs had association with TGW and STI. Several novel QTL for TGW, GL and SL were identified on different chromosomes. Three linked SNPs were transformed into kompetitive allele-specific PCR (KASP) markers. These results will facilitate the discovery of promising SNPs for yield-related traits and/or drought stress tolerance and will accelerate the development of new wheat varieties with desirable alleles.

现代小麦育种的核心目标是培育高产且广适应性的新品种。本研究在三年周期内，于正常栽培条件（Normal Conditions, NC）与干旱胁迫处理条件（Drought Treatment, DT）下，对502份小麦种质资源的4个产量相关农艺性状开展分析。全基因组关联分析（Genome-wide Association Analysis）在小麦中鉴定出51个产量相关、9个抗旱相关的数量性状位点（Quantitative Trait Locus, QTL），其中包括13个千粒重（Thousand-grain Weight, TGW）相关位点、30个粒长（Grain Length, GL）相关位点、3个粒宽（Grain Width, GW）相关位点、5个穗长（Spike Length, SL）相关位点以及9个胁迫耐受指数（Stress Tolerance Index, STI）相关位点。上述关联72个单核苷酸多态性（Single Nucleotide Polymorphisms, SNPs）的QTL，在多环境下可解释2.23%至7.35%的表型变异。位于染色体2A、2D、3B、4A、5B、5D与7D上的8个稳定SNP位点，与正常栽培及干旱胁迫环境下的表型稳定性显著相关；其中2个稳定SNP分别与千粒重和胁迫耐受指数存在关联。研究团队还在不同染色体上鉴定出数个与千粒重、粒长及穗长相关的新型QTL。另有3个连锁SNP被转化为竞争性等位基因特异性PCR（Kompetitive Allele-specific PCR, KASP）标记。本研究结果将助力挖掘产量相关性状及/或干旱胁迫耐受相关的优异SNP位点，并加速携带优良等位基因的小麦新品种选育进程。