Abstract: Abstract: 【Objective】6-SFT is a key gene responsible for the fructan biosynthesis in plants. The objective of the present study was to detect single nucleotide polymorphism (SNP) of 6-SFT-A, determine the relationship between SNP and drought resistance, and mapping it on chromosome of wheat (Triticum aestivum L.). 【Method】Thirty hexaploid wheat accessions with different drought resistance at seedling stage and four T. urartu, the A genome donor species of hexaploid wheat, were selected to detect the nucleotide polymorphism in 6-SFT-A gene by sequencing, and determine the relationship between SNP and drought resistance. Using the recombinant inbred lines (RIL) derived from a cross Yanzhan 1 × Neixiang 188 mapped 6-SFT-A on chromosome. 【Result】Among the 30 hexaploid accessions, 14 polymorphism sites in 6-SFT-A nucleotide sequences were identified, including 13 SNP and one InDel (insertion and deletion) with the polymorphism frequency of 1/234 bp, only two nonsynonymous mutation identified in 1 727 bp and 1 781 bp sites. The introns 1, 2, 3 and exon 3 were detected as the rich nucleotide variation regions. Exon 2 showed the least variation. Compared to the common wheat, T. urartu species exhibited higher sequence variation. Totally, three haplotypes were identified for the plant materials. HaplotypeⅠconsists of wheat accessions with medium-drought resistance and drought sensitivity. Haplotype Ⅲ includes the wheat accessions with high- and medium-drought resistance. Using a population of 190 recombinant inbred lines derived from a cross of Yanzhan 1 × Neixiang 188, 6-SFT-A was mapped on chromosome 4A between SSR markers Xcwm-27 and Xwpt 688, and the genetic distances were 5.3 cM and 7.9 cM from the flanking markers, respectively. 【Conclusion】The present data indicated that SNP in 6-SFT-A gene is associated with wheat seedling drought resistance to some extent.

Key words: wheat (Triticum aestivum L.), 6-SFT-A, single nucleotide polymorphism (SNP), drought resistance, haplotype, genetic mapping