Improvement of RD47 and RD49 for Aroma and Low Amylose Content through Marker-Assisted Selection

Abstract

RD47 and RD49, irrigated rice varieties, produced high yields but have non-aromatic and high amylose content. This research aimed to develop those irrigated rice varieties for aroma and low amylose content. The breeding work was conducted through backcrossing and marker-assisted selection (MAS) for targeted genes badh2 and Wxb. The F1 BC3F1 populations were planted, and heterozygous individuals carrying all targeted genes were selected. The BC3F2-BC3F5 populations were grown, and homozygous genotypes that carried aroma and low amylose targets or only some of the targeted genes were also selected. Promising lines were chosen for amylose content and yield trial evaluation. Six groups of BC3F5 population were selected, including (1) eight and six lines carried homozygous alleles of which genes badh2 and Wxb, with genetic backgrounds of RD47 and RD49, respectively, (2) thirteen lines carried homozygous alleles of which genes badh2 and Wxa (intermediate amylose content), (3) forty lines carried homozygous alleles of which genes badh2 and Wxa (high amylose content), (4) one lines carried homozygous alleles of which genes Badh2 and Wxb, (5) two lines carried homozygous alleles of which genes Badh2 and Wxa (intermediate amylose content) and (6) twenty-four lines carried homozygous alleles of which genes Badh2 and Wxa (high amylose content). The promising line (BC3F5) PSL17018-19-1-2-3, with the RD49 genetic background and carrying homozygous alleles for targeted genes badh2 and Wxb, gave the highest yield of 1,156 kg/rai.