Department of Genetics and Plant Breeding, Ch. Charan Singh University, Meerut, India.
Department of Plant Molecular Biology, University of Delhi, South Campus, New Delhi, India.
Sci Rep. 2019 Dec 20;9(1):19486. doi: 10.1038/s41598-019-55520-0.
Multi-locus genome wide association study was undertaken using a set of 320 diverse spring wheat accessions, which were each genotyped for 9,626 SNPs. The association panel was grown in replicated trials in four environments [two each in irrigated (IR) and rainfed (RF) environments], and phenotypic data were recorded for five traits including days to heading, days to maturity, plant height, thousand grain weight and grain yield. Forty-six significant marker-trait associations (MTAs) were identified for five traits. These included 20 MTAs in IR and 19 MTAs in RF environments; seven additional MTAs were common to both the environments. Five of these MTAs were co-localized with previously known QTL/MTAs and the remaining MTAs were novel and add to the existing knowledge. Three desirable haplotypes for agronomic traits, one for improvement in RF environment and two for improvement in IR environment were identified. Eighteen (18) promising candidate genes (CGs) involved in seven different biological activities were also identified. The expression profiles of four (Trehalose-6-Phosphate, APETALA2/Ethylene-responsive factor, DNA-binding One Zinc Finger and Gibberellin-dioxygenases) of the 18 genes showed that they were induced by drought stress in the wheat seedlings. The MTAs, haplotypes and CG-based markers may be used in marker-assisted breeding for drought tolerance in wheat.
采用一套 320 份不同的春小麦品系进行了多基因座全基因组关联研究，这些品系均针对 9626 个 SNPs 进行了基因型分析。关联小组在四个环境中进行了重复试验[灌溉（IR）和雨养（RF）环境各两个]，并记录了五个性状的表型数据，包括抽穗期、成熟期、株高、千粒重和产量。对五个性状鉴定到 46 个显著的标记-性状关联（MTAs）。这些关联包括 IR 环境中的 20 个 MTA 和 RF 环境中的 19 个 MTA；另外还有 7 个 MTA 是两个环境共有的。其中 5 个 MTA 与先前已知的 QTL/MTAs 共定位，其余的 MTA 是新的，增加了现有的知识。鉴定到 3 个有利的农艺性状单倍型，1 个用于改善 RF 环境，2 个用于改善 IR 环境。还鉴定到 18 个（18）涉及七个不同生物学活性的有前途的候选基因（CGs）。18 个基因中的四个（海藻糖-6-磷酸、APETALA2/乙烯响应因子、DNA 结合锌指和赤霉素双加氧酶）的表达谱显示，它们在小麦幼苗中受到干旱胁迫的诱导。这些 MTA、单倍型和基于 CG 的标记可用于小麦耐旱性的分子标记辅助育种。
