State Key Laboratory of Plant Cell and Chromosome Engineering, Institute of Genetics and Developmental Biology, The Innovative Academy of Seed Design, Chinese Academy of Sciences, Beijing, 100101, China.
University of Chinese Academy of Sciences, Beijing, 100049, China.
Theor Appl Genet. 2021 Jan;134(1):171-189. doi: 10.1007/s00122-020-03689-8. Epub 2020 Sep 29.
QTL for 15 agronomic traits under two levels of salt stress in dry salinity field were mapped in a new constructed RIL population utilizing a Wheat55K SNP array. Furthermore, eight QTL were validated in a collected natural population. Soil salinity is one of the major abiotic stresses causing serious impact on crop growth, development and yield. As one of the three most important crops in the world, bread wheat (Triticum aestivum L.) is severely affected by salinity, too. In this study, an F recombinant inbred line (RIL) population derived from a cross between high-yield wheat cultivar Zhongmai 175 and salt-tolerant cultivar Xiaoyan 60 was constructed. The adult stage performances of the RIL population and their parent lines under low and high levels of salt stress were evaluated for three consecutive growing seasons. Utilizing a Wheat55K SNP array, a high-density genetic linkage map spinning 3250.71 cM was constructed. QTL mapping showed that 90 stable QTL for 15 traits were detected, and they were distributed on all wheat chromosomes except 4D, 6B and 7D. These QTL individually explained 2.34-32.43% of the phenotypic variation with LOD values ranging from 2.68 to 47.15. It was found that four QTL clusters were located on chromosomes 2D, 3D, 4B and 6A, respectively. Notably, eight QTL from the QTL clusters were validated in a collected natural population. Among them, QPh-4B was deduced to be an allele of Rht-B1. In addition, three kompetitive allele-specific PCR (KASP) markers derived from SNPs were successfully designed for three QTL clusters. This study provides an important base for salt-tolerant QTL (gene) cloning in wheat, and the markers, especially the KASP markers, will be useful for marker-assisted selection in salt-tolerant wheat breeding.
在干旱盐胁迫下利用新构建的 RIL 群体利用小麦 55K SNP 阵列对 15 个农艺性状进行 QTL 作图。此外，在收集的自然群体中验证了 8 个 QTL。土壤盐度是导致作物生长、发育和产量严重受损的主要非生物胁迫之一。作为世界上三种最重要的作物之一，面包小麦（Triticum aestivum L.）也受到盐胁迫的严重影响。在这项研究中，利用来自高产小麦品种 Zhongmai 175 和耐盐品种 Xiaoyan 60 杂交的 F 重组自交系（RIL）群体，对其在低水平和高水平盐胁迫下的成株期表现进行了连续 3 个生长季节的评估。利用小麦 55K SNP 阵列，构建了一个旋转 3250.71 cM 的高密度遗传连锁图谱。QTL 作图表明，在 15 个性状中检测到 90 个稳定的 QTL，它们分布在除 4D、6B 和 7D 以外的所有小麦染色体上。这些 QTL 分别解释了 2.34-32.43%的表型变异，LOD 值范围为 2.68-47.15。发现四个 QTL 簇分别位于染色体 2D、3D、4B 和 6A 上。值得注意的是，在收集的自然群体中验证了 QTL 簇中的 8 个 QTL。其中，QPh-4B 被推断为 Rht-B1 的等位基因。此外，从 SNPs 中成功设计了三个竞争性等位基因特异性 PCR（KASP）标记。这项研究为小麦耐盐 QTL（基因）克隆提供了重要基础，标记，特别是 KASP 标记，将有助于耐盐小麦的分子标记辅助选择。
