Identification and Mapping of QTLs for Grain Quality Traits in Rice Oryza sativa L

Abstract

newline The present study entitled and#8246;Identification and Mapping of QTLs for Grain Quality Traits in Rice (Oryza sativa L.)and#8243; was conducted at School of Biotechnology, SKUAST-Jammu during 2019-2022 to characterize a novel CSSL population using marker assisted selection; to identify QTLs for grain and quality traits using CSSL population; and to fine map the major QTLs for marker assisted selection. A BC3F2 (convergent) population was developed using K 343 as recurrent parent and DHMAS and RML 22 as donor parents. The population was characterized for yield attributing and grain quality traits such as plant height, days to 50 percent flowering, days to maturity, effective tillers per plant, panicle length, grain length, grain width, thousand grain weight, protein content and amylose content. The data were analysed using R-software. Significant variation was observed among parents and 146 lines comprising the population. Some of the lines with significantly higher protein content could prove promising. The population was genotyped using 74 SSR markers and the genotypic data were screened using GGT 2.0 software which depicted 96.7 percent of the recurrent genome recovery covering 13953.6 cM while DHMAS and RML 22 showed 1.6 percent (235.5 cM) and 1.2 percent (177.1 cM) genomic introgression, respectively. CSSL Finder software identified 36 CSSLs (22 for DHMAS/K 343 and 14 for RML 22/K 343). The DHMAS-K 343 CSSL population had donor genome introgression ranging from 0.54 percent to 9.57 percent, while 0.54 percent to 4.78 percent of donor genome introgression was observed in RML22-K343 CSSL population. The donor introgressed segments had an average length of 2.05 cM and 1.88 cM with coverage percentage of 41.33 percent and 33.22 percent, respectively in DHMAS-K343 and RML22-K343 CSSL populations. The BC3F2 (convergent) population was used for constructing linkage map of 12 chromosomes based on genotypic data obtained using software program IciMapping v4.0 with threshold LOD score of 2.5. A total of 12 QTLs were