National Engineering Research Center of Crop Molecular Breeding, Institute of Crop Sciences, Chinese Academy of Agricultural Sciences, Beijing, 100081, China.
College of Agronomy and Biotechnology, Hebei Normal University of Science & Technology, Qinhuangdao, 066004, China.
BMC Plant Biol. 2022 Jul 6;22(1):326. doi: 10.1186/s12870-022-03710-w.
Pre-harvest sprouting (PHS) is a serious limiting factor for wheat (Triticum aestivum L.) grain yield and end-use quality. Identification of reliable molecular markers and PHS-resistant germplasms is vital to improve PHS resistance by molecular marker-assisted selection (MAS), but the effects of allelic variation and haplotypes in genes conferring PHS resistance in winter wheat cultivars are less understood.
Resistance to PHS was tested in 326 commercial winter wheat cultivars for three consecutive growing seasons from 2018-2020. The effects of alleles and haplotypes of 10 genes associated with PHS resistance were determined for all cultivars and were validated by introgressing the PHS-resistance allele and haplotype into a susceptible wheat cultivar. High level of phenotypic variation in PHS resistance was observed in this set of cultivars and 8 of them were highly resistant to PHS with stable germination index (GI) of less than 25% in each individual year. Allelic effects of nine genes and TaMFT haplotype analysis demonstrated that the haplotype Hap1 with low-GI alleles at five positions had the best PHS resistance. This haplotype has the priority to use in improving PHS resistance because of its high effectiveness and rare present in the current commercial cultivars. Among 14 main allelic combinations (ACs) identified, the AC1 carrying the haplotype Hap1 and the TaSdr-B1a allele had better PHS resistance than the other classes. The introgression of Hap1 and TaSdr-B1a is able to significantly improve the PHS resistance in the susceptible cultivar Lunxuan 13.
The effectiveness of alleles conferring PHS resistance in winter wheat cultivars was determined and the useful alleles and haplotypes were identified, providing valuable information for parental selection and MAS aiming at improving PHS-resistance in winter wheat. The identification of the PHS-resistant cultivars without known resistance alleles offers an opportunity to explore new PHS-resistant genes.
收获前发芽（PHS）是冬小麦（Triticum aestivum L.）籽粒产量和食用品质的严重限制因素。鉴定可靠的分子标记和 PHS 抗性种质对于通过分子标记辅助选择（MAS）提高 PHS 抗性至关重要，但冬小麦品种中赋予 PHS 抗性的等位基因变异和单倍型的影响知之甚少。
在 2018-2020 年的三个连续生长季节中，对 326 个商业冬小麦品种进行了 PHS 抗性测试。确定了与 PHS 抗性相关的 10 个基因的等位基因和单倍型对所有品种的影响，并通过将 PHS 抗性等位基因和单倍型导入易感小麦品种进行验证。在这组品种中观察到 PHS 抗性的表型变异程度很高，其中 8 个品种对 PHS 具有高度抗性，每个品种的发芽指数（GI）均稳定在 25%以下。九个基因的等位基因效应和 TaMFT 单倍型分析表明，具有五个位置低-GI 等位基因的单倍型 Hap1 具有最佳的 PHS 抗性。由于其高效性和在当前商业品种中罕见，该单倍型优先用于提高 PHS 抗性。在鉴定的 14 个主要等位基因组合（AC）中，携带单倍型 Hap1 和 TaSdr-B1a 等位基因的 AC1 比其他类别具有更好的 PHS 抗性。Hap1 和 TaSdr-B1a 的导入能够显著提高易感品种 Lunxuan 13 的 PHS 抗性。
确定了冬小麦品种中赋予 PHS 抗性的等位基因的有效性，并鉴定了有用的等位基因和单倍型，为旨在提高冬小麦 PHS 抗性的亲本选择和 MAS 提供了有价值的信息。鉴定无已知抗性等位基因的 PHS 抗性品种为探索新的 PHS 抗性基因提供了机会。
