Development and Characterization of Near-Isogenic Lines Revealing Candidate Genes for a Major 7AL QTL Responsible for Heat Tolerance in Wheat

Lu Lu; Hui Liu; Yu Wu; Guijun Yan

doi:10.3389/fpls.2020.01316

Development and Characterization of Near-Isogenic Lines Revealing Candidate Genes for a Major 7AL QTL Responsible for Heat Tolerance in Wheat

Front Plant Sci. 2020 Aug 28:11:1316. doi: 10.3389/fpls.2020.01316. eCollection 2020.

Authors

Lu Lu^{1

2

3}, Hui Liu^{1

2}, Yu Wu³, Guijun Yan^{1

2}

Affiliations

¹ Faculty of Science, UWA School of Agriculture and Environment, The University of Western Australia, Perth, WA, Australia.
² The UWA Institute of Agriculture, The University of Western Australia, Perth, WA, Australia.
³ Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu, China.

Abstract

Wheat is one of the most important food crops in the world, but as a cool-season crop, it is more prone to heat stress, which severely affects crop production and grain quality. Heat tolerance in wheat is a quantitative trait, and the genes underlying reported quantitative trait loci (QTL) have rarely been identified. Near-isogenic lines (NILs) with a common genetic background but differing at a particular locus could turn quantitative traits into a Mendelian factor; therefore, they are suitable material for identifying candidate genes for targeted locus/loci. In this study, we developed and characterized NILs from two populations Cascades × Tevere and Cascades × W156 targeting a major 7AL QTL responsible for heat tolerance. Molecular marker screening and phenotyping for SPAD chlorophyll content and grain-yield-related traits confirmed four pairs of wheat NILs that contrasted for heat-stress responses. Genotyping the NILs using a 90K Infinium iSelect SNP array revealed five single nucleotide polymorphism (SNP) markers within the QTL interval that were distinguishable between the isolines. Seven candidate genes linked to the SNPs were identified as related to heat tolerance, and involved in important processes and pathways in response to heat stress. The confirmed multiple pairs of NILs and identified candidate genes in this study are valuable resources and information for further fine-mapping to clone major genes for heat tolerance.

Keywords: 7AL; candidate genes; heat tolerance; near-isogenic lines; quantitative trait loci; single nucleotide polymorphism assay; wheat.