Abstract:

【Objective】 Waxy gene (Wx in short) is a key gene responsible for the barley amylose synthesis. The objective of the present study was to detect single nucleotide polymorphisms (SNP) of Wx and determine the relationship between SNP and amylose content of seed in barley. 【Method】 After PCR amplification and gene clone, 30 Chinese normal and waxy barley cultivars, which had high, medium and low amylose content respectively, were sequenced and polymorphism was analyzed for waxy gene with 2 Canadian waxy barley as controls. 【Result】 By polymorphism identification of waxy gene nucleotide sequences for the 32 barley cultivars, 169 polymorphism sites were identified, which included 143 SNP and 26 InDel with frequencies of 1/310 and 1/196, respectively. It was found that the introns 1,3,5,8, exons 2,5 and 5′-UTR, 3′-UTR were the rich nucleotide variation regions. Exon 2 and intron 1 suffered stronger selection pressure. Four haplotypes were identified from 32 plant materials. Among them, haplotype 1 included all low amylose content accessions. 【Conclusion】 The results of research showed that there is a clear correlation between SNPs in waxy gene and amylose content in barley.

Key words: barley, Wx, single nucleotide polymorphism, haplotype, amylose content