Dissection of starch composition and physicochemical property in barley shrunken mutants

In this study, the starch composition and physicochemical properties were determined in 47 barley accessions with varying mutant types including shrunken endosperm, waxy endosperm, high lysine, and male-sterile genetic. These accession had significant variation among themselves as the total starch content ranged from 22.6 to 62.0%, a variation from 6.7 to 42.2% was observed for the amylose content and the amylose/amylopectin ratio of these accessions was changing from 0.07 to 0.70. On the basis of amylose content, the resistant starch content of 22 accessions was measured and the resistant starch content of BM20 (1.74%), BM24 (7.90%), BM27 (1.78%), and BM40 (5.93%) increased significantly. The BM24 accession was identified as a mutant lacking the starch synthase I (SSI), starch synthase II (SSII), and starch branching enzyme II (SBEII) by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE), and the size and morphology of A-type starch granules BM24 changed obviously. This study identified non-transgenic barley accessions with high amylose, high resistant starch, and enlarged starch granules which will be useful for breeding and studying the mechanism of starch synthesis.