CHARACTERIZATION OF MICROSATELLITES IN STARCH - SYNTHESIZING GENES OF SOME VIETNAMESE RICE ACCESSIONS

Abstract

Starch comprises  90% of milled rice and it is composed of amylose and amylopectin. The synthesis of starch in rice endosperm is primarily controlled by wx, she, sss genes. The wx gene encoding granulebound starch synthase (GBSS) plays a major role in the synthesis of amylose. The sbe gene encoding starch branching enzyme I (SBE) and the sss gene encoding soluble starch Synthasel (SSS) playa major role in the synthesis of amylopectin. The study of the relationship between the wx (CT)_n, sbe (CT)_n, sss (CT)_n microsatellites and starch quality parameters has been previously reported. In this study, we used primers for amplifying microsatellites in the wx and she genes in 17 rice accessions (varieties and breeding lines). Five of the 17 accessions were indica and 12 werejaponica rice. Four alleles of wx gene were amplified in 17 rice accessions, the amplified products ranged from 120 to 126 bp in length. Two alleles of she (CT)n were amplified in a region of the sbe gene in both the indica and japonica rice subspecies