Yang Bin, Wen Xiaojie, Wen Hongwei, Feng Yanru, Zhao Jiajia, Wu Bangbang, Zheng Xingwei, Yang Chenkang, Yang Sanwei, Qiao Ling, Zheng Jun
Institute of Wheat Research, Shanxi Agricultural University/ State Key Laboratory of Sustainable Dryland Agriculture, Linfen, China.
College of Agricultural Economics and Management, Shanxi Agricultural University, Taiyuan, China.
Front Genet. 2022 Mar 15;13:832898. doi: 10.3389/fgene.2022.832898. eCollection 2022.
Chlorophyll content of the flag leaf is an important trait for drought resistance in wheat under drought stress. Understanding the regulatory mechanism of flag leaf chlorophyll content could accelerate breeding for drought resistance. In this study, we constructed a recombinant inbred line (RIL) population from a cross of drought-sensitive variety DH118 and drought-resistant variety Jinmai 919, and analyzed the chlorophyll contents of flag leaves in six experimental locations/years using the Wheat90K single-nucleotide polymorphism array. A total of 29 quantitative trait loci (QTLs) controlling flag leaf chlorophyll were detected with contributions to phenotypic variation ranging from 4.67 to 23.25%. Twelve QTLs were detected under irrigated conditions and 18 were detected under dryland (drought) conditions. Most of the QTLs detected under the different water regimes were different. Four major QTLs (, , , and ) were detected in the RIL population. , possibly more suitable for marker-assisted selection of genotypes adapted to irrigated conditions, was validated by a tightly linked kompetitive allele specific PCR (KASP) marker in a doubled haploid population derived from a different cross. , a novel stably expressed QTL, was detected in the dryland environments and explained up to 23.25% of the phenotypic variation, and has potential for marker-assisted breeding of genotypes adapted to dryland conditions. The stable and major QTLs identified here add valuable information for understanding the genetic mechanism underlying chlorophyll content and provide a basis for molecular marker-assisted breeding.
旗叶叶绿素含量是干旱胁迫下小麦抗旱性的一个重要性状。了解旗叶叶绿素含量的调控机制有助于加速抗旱育种进程。本研究以干旱敏感品种DH118和抗旱品种晋麦919杂交构建了重组自交系（RIL）群体，并利用小麦90K单核苷酸多态性芯片分析了六个试验地点/年份的旗叶叶绿素含量。共检测到29个控制旗叶叶绿素的数量性状位点（QTL），对表型变异的贡献率为4.67%至23.25%。在灌溉条件下检测到12个QTL，在旱地（干旱）条件下检测到18个QTL。不同水分条件下检测到的大多数QTL是不同的。在RIL群体中检测到4个主要QTL（、、和）。通过一个紧密连锁的竞争性等位基因特异性PCR（KASP）标记在另一个杂交产生的双单倍体群体中验证了可能更适合于标记辅助选择适应灌溉条件基因型的。在旱地环境中检测到一个新的稳定表达的QTL，其对表型变异的解释率高达23.25%，具有标记辅助选育适应旱地条件基因型的潜力。本研究鉴定出的稳定且主要的QTL为理解叶绿素含量的遗传机制提供了有价值的信息，并为分子标记辅助育种奠定了基础。
