Tasmanian Institute of Agriculture, University of Tasmania, Hobart, Australia.
International Research Centre for Environmental Membrane Biology, Foshan University, Chancheng, China.
Theor Appl Genet. 2022 Feb;135(2):709-721. doi: 10.1007/s00122-021-03996-8. Epub 2021 Nov 19.
Soil salinity is a major threat to crop productivity and quality worldwide. In order to reduce the negative effects of salinity stress, it is important to understand the genetic basis of salinity tolerance. Identifying new salinity tolerance QTL or genes is crucial for breeders to pyramid different tolerance mechanisms to improve crop adaptability to salinity. Being one of the major cereal crops, wheat is known as a salt-sensitive glycophyte and subject to substantial yield losses when grown in the presence of salt. In this study, both pot and tank experiments were conducted to investigate the genotypic variation present in 328 wheat varieties in their salinity tolerance at the vegetative stage. A Genome-Wide Association Studies (GWAS) were carried out to identify QTL conferring salinity tolerance through a mixed linear model. Six, five and eight significant marker-trait associations (MTAs) were identified from pot experiments, tank experiments and average damage scores, respectively. These markers are located on the wheat chromosomes 1B, 2B, 2D, 3A, 4B, and 5A. These tolerance alleles were additive in their effects and, when combined, increased tolerance to salinity. Candidate genes identified in these QTL regions encoded a diverse class of proteins involved in salinity tolerance in plants. A Na/H exchanger and a potassium transporter on chromosome 5A (IWB30519) will be of a potential value for improvement of salt tolerance of wheat cultivars using marker assisted selection programs. Some useful genotypes, which showed consistent tolerance in different trials, can also be effectively used in breeding programs.
土壤盐度是全球范围内作物生产力和质量的主要威胁。为了降低盐胁迫的负面影响，了解盐度耐受性的遗传基础很重要。鉴定新的耐盐性 QTL 或基因对于培育者来说至关重要，他们可以将不同的耐受机制进行聚合，以提高作物对盐度的适应能力。小麦作为主要的谷类作物之一，被认为是一种对盐敏感的盐生植物，在盐胁迫下会导致大量减产。本研究通过盆栽和水培实验，研究了 328 个小麦品种在营养生长阶段的耐盐性的基因型变异。通过混合线性模型进行全基因组关联研究（GWAS），以鉴定赋予耐盐性的 QTL。从盆栽实验、水培实验和平均损伤评分中分别鉴定出 6、5 和 8 个显著的标记-性状关联（MTAs）。这些标记位于小麦染色体 1B、2B、2D、3A、4B 和 5A 上。这些耐盐等位基因的效应是累加的，当它们组合在一起时，会增加对盐度的耐受性。在这些 QTL 区域中鉴定出的候选基因编码了一类参与植物耐盐性的不同功能的蛋白质。5A 染色体上的 Na/H 交换器和钾转运体（IWB30519）可能对利用标记辅助选择程序改良小麦品种的耐盐性具有潜在价值。一些在不同试验中表现出一致耐受性的有用基因型也可以有效地用于育种计划。
