小麦抗旱基因TaDROT-6B1克隆、功能标记开发与验证OA

Drought is the main environmental factor affecting wheat production,and the breeding and application of drought-resistant varieties are important for ensuring national food security.To identify drought-resistant genes and their superior haplotypes,the rice DROT1 homologous gene TraesCS6B02G418400(TaDROT1-6B)was cloned from ten cultivars in this study.This gene is 3,340 bp in length with six exons and five introns,encoding a 447 amino acid protein.Sequence analysis revealed seven single-nucleotide polymorphisms(SNPs),and one insertion mutation among the cultivars,which were grouped into two haplotypes for TaDROT1-6B.Haplotype Ⅰ included low-to-moderate drought-resistant cultivars(e.g.,Luomai 42,Luomai 47,Zhongmai 30,Zhongmai 895,Zhongmai 175,Luohan 22),while haplotype Ⅱ comprised strong drought-resistant cultivars(Luohan 2,Luohan 7,Luohan 28,Jinmai 47).Haplotype Ⅱ carried a TCC insertion at 1,362 bp downstream of the start codon in exon 3,encoding a serine.At 64 bp downstream of the start codon in exon 1,haplotype Ⅰ carried a G(encoding alanine),whereas haplotype Ⅱ had an A(resulting in a threonine substitution).A KASP marker was developed to discriminate the two haplotypes and was validated in a natural population.Under normal conditions,thousand grain weight of haplotype Ⅱ and haplotype Ⅰ was significantly increased by 17.1％and 13.2％,respectively,compared with that under drought treatment.Similarly,plant height of haplotype Ⅱ and haplotype I was significantly increased by 8.0％and 16.0％,respectively,compared with that under drought treatment.This study provides important genetic resources and molecular markers for the improvement of wheat drought-resistant cultivars.