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 Sep;134(9):2991-3011. doi: 10.1007/s00122-021-03872-5. Epub 2021 Jun 6.
The genetic basis of 27 seedling traits under normal and salt treatments was fully analyzed in a RIL wheat population, and seven QTL intervals were validated in two other genetic populations. Soil salinity seriously constrains wheat (Triticum aestivum L.) production globally by influencing its growth and development. To explore the genetic basis of salt tolerance in wheat, a recombinant inbred line (RIL) population derived from a cross between high-yield wheat cultivar Zhongmai 175 (ZM175) and salt-tolerant cultivar Xiaoyan 60 (XY60) was used to map QTL for seedling traits under normal and salt treatments based on a high-density genetic linkage map. A total of 158 stable additive QTL for 27 morphological and physiological traits were identified and distributed on all wheat chromosomes except 3A and 4D. They explained 2.35-46.43% of the phenotypic variation with a LOD score range of 2.61-40.38. The alleles from XY60 increased corresponding traits for 100 QTL, while the alleles from ZM175 had positive effects for the other 58 QTL. Nearly half of the QTL (78/158) were mapped in nine QTL clusters on chromosomes 2A, 2B, 2D, 4B, 5A, 5B, 5D, and 7D (2), respectively. To prove the reliability and potentiality in molecular marker-assisted selection (MAS), seven QTL intervals were validated in two other genetic populations. Besides additive QTL, 94 pairs of loci were detected with significant epistatic effect and 20 QTL were found to interact with treatment. This study provides a full elucidation of the genetic basis of seedling traits (especially root system-related traits) associated with salt tolerance in wheat, and the developed kompetitive allele-specific PCR markers closely linked to stable QTL would supply strong supports to MAS in salt-tolerant wheat breeding.
在一个 RIL 小麦群体中，充分分析了正常和盐处理下 27 个幼苗性状的遗传基础，并在另外两个遗传群体中验证了七个 QTL 区间。土壤盐度通过影响小麦的生长和发育，严重限制了全球小麦的生产。为了探索小麦耐盐性的遗传基础，利用中麦 175（ZM175）和耐盐品种小偃 60（XY60）杂交衍生的重组自交系（RIL）群体，基于高密度遗传连锁图谱，对正常和盐处理下幼苗性状的 QTL 进行了定位。共鉴定出 158 个稳定的加性 QTL，可解释 27 个形态和生理性状的 2.35-46.43%表型变异，LOD 得分范围为 2.61-40.38。来自 XY60 的等位基因增加了 100 个 QTL 对应的性状，而来自 ZM175 的等位基因对另外 58 个 QTL 有积极影响。近一半的 QTL（78/158）分别位于染色体 2A、2B、2D、4B、5A、5B、5D 和 7D（2）的九个 QTL 簇中。为了证明在分子标记辅助选择（MAS）中的可靠性和潜力，在另外两个遗传群体中验证了七个 QTL 区间。除了加性 QTL，还检测到 94 对具有显著上位性效应的位点，发现 20 个 QTL 与处理相互作用。本研究充分阐明了与小麦耐盐性相关的幼苗性状（特别是根系相关性状）的遗传基础，开发的与稳定 QTL 紧密连锁的竞争性等位基因特异性 PCR 标记将为耐盐小麦的 MAS 提供有力支持。
