Use of Marker-Assisted Selection In Developing Submergence Tolerant Rice (Oryza sativa var Swarna) in the BC2 F3 Generation

Abstract

Destruction of crops due to submergence is a growing concern in flood-prone environments. This has led urgent need for the incorporation of the Swub-I locus for submergence tolerance in chromosome 9 of popular rice varieties. Swarna, a popular rice variety in South Asia was crossed and backcrossed to IR49830, a Sub-I donor using Marker Assisted Backcrossing (MAB). In this descriptive study, plants in the third filial generation of the second backcross (BC,F3) stage were screened for submergence-tolerance. DNA was extracted from leaf samples collected from each plant then genotyped for inheritance at specific loci of interest thru Marker Assisted Selection (MAS) using molecular markers (SSR markers) in the Sub-/ locus (RM316, SSC3, SSRI, RM464, RM464A), as well as molecular markers for other regions (RM8S5, RM119, RM163, RM246, RM428). Certain plants that contained IR49830 (donor parent) genotype in the Sub-1 locus and Swarna (recurrent parent) genotype in all of the other loci are of particular interest. Candidate plants were seeded and subjected to submergence check. Results indicated that certain rice lines contained Swarna genotypes in all but the Sub-I locus, thus, identifying submergence-tolerant rice lines for Swarna.