干旱胁迫对中亚大麦农艺性状的影响及其相关基因定位

干旱是影响大麦产量的主要非生物胁迫之一。挖掘大麦干旱响应基因,有利于大麦耐旱品种的改良。本研究以167份中亚大麦品种为材料,测定正常灌水(出苗期、拔节期、孕穗期、抽穗期、灌浆期各灌水1次)、灌水2次(出苗期、孕穗期各灌水1次)以及灌水1次(出苗期灌水1次)处理下大麦的株高、穗长、单株穗数和主穗小穗数,结合群体分子信息,对这4个性状进行全基因组关联分析(genome-wide association study,GWAS)。结果表明,167份中亚大麦没有明显的地理亚群。全基因组关联分析共鉴定到8个与性状关联的位点,筛选到17个与大麦抗旱性相关的潜在候选基因,其中,调控大麦株高、穗长、主穗小穗数和单株穗数的候选基因分别有7、4、4和2个。同时,对耐旱系数(drought tolerance index,DI)进行GWAS关联分析,鉴定到7个与大麦耐旱相关的QTL,分布在1H、4H、5H和7H染色体上,存在96个潜在候选基因。该研究为后期大麦分子育种和抗旱功能基因克隆提供了基础数据。

Responses to Drought Stress and Gene Mapping of Related Agronomic Traits of Central Asian Barley

Drought is one of the main abiotic stresses that affect the yield of barley.Exploring drought response genes of barley is beneficial to variety improvement. In this study,we analyzed the population evolution of 167 Central Asian barley accessions under three irrigation regimes,namely normal irrigation(irrigating at seedling,elongation,booting,heading and filling stages),irrigation twice(irrigating at seedling and booting stages) and irrigation once(irrigating at seedling stage). Plant height,ear length,spikelet number and spike number per plant were evaluated for genome-wide association study(GWAS). We found that there were no obvious geographical subgroups. A total of eight QTL loci were found to be associated with the four agronomic traits. Further functional analysis identified 17 candidate genes,and there were 7,4,4 and 2 candidate genes regulating plant height,ear length,spikelet number and spike number per plant of barely,respectively. At the same time,GWAS was performed according to the drought index(DI) phenotype,and seven QTLs were identified on 1H,4H,5H and 7H chromosomes,underlying 96 promising candidate genes. This study provides basic data for further molecular breeding and cloning functional genes for drought resistance in barley.