A new SSR marker for puroindoline genes of wheat

摘要

Allelic variation in puroindoline genes determines the hardness of the important quality traits in wheat grain. In this study, a simple sequence repeat (SSR) SSR 7 was chosen from the puroindoline genome sequence. It resided at 495 bp before the startcodon of Pina. The repeat number of SSR 7 was different in different types of common wheat and Ae. tauschii. Four repeat types existed in 34 wheat cultivars with the repeat numbers 16, 18, 19 and 20, respectively. Among the 24 classes of materials of Ae. tauschii, only two repeat types, 6 and 10 times, could be found. Moreover, common wheat cultivars had one or two ‘AC’s more than Ae. tauschii. Except for AS 61 and AS 81, a 13 bps deletion appeared at 165 bp upstream of the SSR 7 site of the rest varieties of Ae. tauschii. The segment sizes of SSR 7 PCR product in common wheat were predicted from 154-182 bps, with the segment size not linked closely to puroindoline genotype. The allelic variations existing at SSR 7 loci can provide the theory basisfor marker-assisted selection breeding in wheat hardness.