A mutation in Waxy gene affects amylose content, starch granules and kernel characteristics of barley (Hordeum vulgare)

Waxy barley referred to as low-amylose or amylose-free has special advantages in nutrition composition and food processing. Waxy gene encoding granule-bound starch synthase I (GBSSI) is responsible for amylose synthesis in barley. The G(3935)-to-T in Waxy gene has been previously found in amylose-free barley. In this study, G(3935)-to-T was proved to co-segregate with the waxy phenotype of barley, but has no obvious effect on GBSSI catalytic activity and starch chain length distribution. However, recombinant inbred lines with G(3935)-to-T in Waxy gene are of significant modification in starch granules morphology and pasting properties, increase of grain beta-glucan content, and decrease of thousand kernel weight along with lower kernel width. A polymerase chain reaction with confronting two-pair primers marker was developed for economic and efficient screening of G(3935)-to-T. This study provides the basis for cultivar improvement of waxy barley then fully developing its potential value and utility in food processing.