El Gataa Zakaria, Samir Karima, Tadesse Wuletaw
The International Center for Agricultural Research in the Dry Areas (ICARDA), Rabat 10080, Morocco.
Faculty of Sciences Ben M'sick, University Hassan II of Casablanca, Casablanca 7955, Morocco.
Plants (Basel). 2022 Oct 13;11(20):2705. doi: 10.3390/plants11202705.
Drought is one of the most important yield-limiting factors in Morocco. Identification and deployment of drought-tolerant wheat varieties are important to cope with the challenge of terminal moisture stress and increase wheat productivity. A panel composed of 200 elite spring bread wheat genotypes was phenotyped for yield and agronomic traits for 2 years (2020 and 2021) in Morocco under rainfed and irrigated environments. The panel was genotyped using 20K SNPs and, after filtration, a total of 15,735 SNP markers were used for a genome-wide association study (GWAS) using a mixed linear model (MLM) to identify marker-trait associations (MTA) and putative genes associated with grain yield and yield-related traits under rainfed and irrigated conditions. Significant differences were observed among the elite genotypes for grain yield and yield-related traits. Grain yield performance ranged from 0.97 to 6.16 t/ha under rainfed conditions at Sidi Al-Aidi station and from 3.31 to 9.38 t/h under irrigated conditions at Sidi Al-Aidi station, while Grain yield at Merchouch station ranged from 2.32 to 6.16 t/h under rainfed condition. A total of 159 MTAs (p < 0.001) and 46 genes were discovered, with 67 MTAs recorded under rainfed conditions and 37 MTAs recorded under irrigated conditions at the Sidi Al-Aidi station, while 55 MTAs were recorded under rainfed conditions at Merchouch station. The marker ‘BobWhite_c2988_493’ on chromosome 2B was significantly correlated with grain yield under rainfed conditions. Under irrigated conditions, the marker ‘AX-94653560’ on chromosome 2D was significantly correlated with grain yield at Sidi Al-Aidi station. The maker ‘RAC875_c17918_321’ located on chromosome 4A, associated with grain yield was linked with the gene TraesCS4A02G322700, which encodes for F-box domain-containing protein. The markers and candidate genes discovered in this study should be further validated for their potential use in marker-assisted selection to generate high-yielding wheat genotypes with drought tolerance.
干旱是摩洛哥最重要的限产因素之一。鉴定和推广耐旱小麦品种对于应对生育后期水分胁迫挑战和提高小麦产量至关重要。由200个优良春性面包小麦基因型组成的群体，于2020年和2021年在摩洛哥雨养和灌溉环境下对产量和农艺性状进行了两年的表型分析。该群体使用20K单核苷酸多态性（SNP）进行基因分型，经过筛选后，共15735个SNP标记用于全基因组关联研究（GWAS），采用混合线性模型（MLM）来鉴定标记-性状关联（MTA）以及与雨养和灌溉条件下的籽粒产量及产量相关性状相关的推定基因。在优良基因型之间，籽粒产量和产量相关性状存在显著差异。在西迪·艾迪站雨养条件下，籽粒产量表现为0.97至6.16吨/公顷，在西迪·艾迪站灌溉条件下为3.31至9.38吨/公顷，而在梅尔舒什站雨养条件下，籽粒产量为2.32至6.16吨/公顷。共发现159个MTA（p < 0.001）和46个基因，在西迪·艾迪站雨养条件下记录到67个MTA，灌溉条件下记录到37个MTA，而在梅尔舒什站雨养条件下记录到55个MTA。2B染色体上的标记“BobWhite_c2988_493”与雨养条件下的籽粒产量显著相关。在灌溉条件下，2D染色体上的标记“AX-94653560”与西迪·艾迪站的籽粒产量显著相关。位于4A染色体上与籽粒产量相关的标记“RAC875_c17918_321”与编码含F-box结构域蛋白的基因TraesCS4A02G322700连锁。本研究中发现的标记和候选基因应进一步验证其在标记辅助选择中的潜在用途，以培育具有耐旱性的高产小麦基因型。
