Genetic and molecular analysis of grain linear elongation ratio in Rice Oryza sativa L

Abstract

The present investigation on Genetic and molecular analysis of grain linear elongation ratio of rice (Oryza sativa L.) was carried out at Department of Rice, Tamil Nadu Agricultural University, Coimbatore during Kharif 2021 to Rabi 2022 to study the genetic variability, genetic diversity, combining ability, estimation of epistasis and identification of putative QTLs. Moderate to high GCV and PCV were observed for all the studied traits except panicle length that showed low variability components, while the trait, gel consistency showed low GCV and moderate PCV. The heritability and the genetic advance as per cent of mean were found to be high for all the studied traits except panicle length and gel consistency which had moderate level of heritability and genetic advance. Combined results of the per se performance, Mahalanobis D2 and PCA gave the lead for the correct choice of parents for the hybridization programme for improving the grain quality traits. The traits L/B ratio and kernel breadth were identified to be the most contributing ones for the total divergence. Combining the results of the per se performance, D2 and PCA, the genotypes viz., Pusa Basmati 1121, Pusa Basmati 1 had good physico-chemical grain qualities, while Improved white ponni, BPT 5204, RNR 15048 had good yielding and grain quality attributes. Apart from these, the genotypes, TPS 5, TRY 3, Palawan and Azucena had good yielding ability but were having bold grains and lower linear newlineelongation ratio. Hence, the contrasting genotypes, Pusa Basmati 1121, Pusa Basmati 1, Improved white ponni, BPT 5204 and RNR 15048 were selected as lines and the genotypes viz., TPS 5, TRY 3, Palawan and Azucena can be made as testers to get elite recombinants with high grain yield and quality. newlineFrom the evaluation of the twenty hybrids obtained from the Line x Tester analysis, the GCA/SCA variance was less than one for all the traits except days to 50 per cent flowering, kernel L/B ratio, kernel length after cooking and kernel breadth after cooking.