Tahghighi Hediyeh, Erskine William, Bennett Richard G, Bayer Philipp E, Pazos-Navarro Maria, Kaur Parwinder
Centre for Plant Genetics and Breeding, School of Agriculture and Environment, The University of Western Australia, Perth, WA, Australia.
Institute of Agriculture, The University of Western Australia, Perth, WA, Australia.
Front Plant Sci. 2019 Aug 30;10:1043. doi: 10.3389/fpls.2019.01043. eCollection 2019.
In alkaline soils in arid and semi-arid areas toxic concentrations of the micronutrient boron (B) are problematic for many cereal and legume crops. Molecular markers have been developed for B toxicity in cereals and . There is a need for such tools in clovers-. To this end, we undertook a genome-wide association study (GWAS) with a diversity panel of subterranean clover ( L.), an established model pasture legume for genetic and genomic analyses for the genus. The panel comprised 124 genotypes (97 core collection accessions and 27 Australian cultivars). Substantial and useful diversity in B toxicity tolerance was found in . Such variation was continuously distributed and exhibited a high broad sense heritability = 0.92. Among the subspecies of , ssp. was most susceptible to B toxicity ( < 0.05). From the GWAS, the most important discoveries were single-nucleotide polymorphisms (SNPs) located on Chr 1, 2, and 3, which mapped to haplotype blocks providing potential genes for a B toxicity tolerance assay and meriting further investigation. A SNP identified on Chr 1 aligned with respiratory burst oxidase-like protein (TSub_ g2235). This protein is known to respond to abiotic and biotic stimuli. The identification of these novel potential genes and their use to design markers for marker-assisted selection offer a pathway in pasture legumes to manage B toxicity by exploiting B tolerance.
在干旱和半干旱地区的碱性土壤中，微量营养素硼（B）的毒性浓度对许多谷类和豆类作物来说是个问题。已经开发出了针对谷类作物硼毒性的分子标记。而三叶草属植物也需要这样的工具。为此，我们对地下三叶草（Trifolium subterraneum L.）的一个多样性群体进行了全基因组关联研究（GWAS），地下三叶草是该属遗传和基因组分析中已确立的模式牧草豆科植物。该群体由124个基因型组成（97个核心种质资源 accession 和27个澳大利亚品种）。在地下三叶草中发现了对硼毒性耐受性的显著且有用的多样性。这种变异呈连续分布，表现出较高的广义遗传力（H² = 0.92）。在地下三叶草的亚种中，ssp. brachycalycinum对硼毒性最敏感（P < 0.05）。通过全基因组关联研究，最重要的发现是位于第1、2和3号染色体上的单核苷酸多态性（SNP），这些SNP定位到单倍型块，为硼毒性耐受性检测提供了潜在基因，值得进一步研究。在第1号染色体上鉴定出的一个SNP与呼吸爆发氧化酶样蛋白（TSub_g2235）对齐。已知该蛋白对非生物和生物刺激有反应。这些新潜在基因的鉴定及其用于设计标记辅助选择的标记，为牧草豆科植物通过利用硼耐受性来管理硼毒性提供了一条途径。
