Genetic Variability, Character Association, and Path Coefficient Analysis for Yield and Grain Quality Traits in Indian Basmati Rice (Oryza sativa L.) Genotypes

Abstract

Basmati rice (Oryza sativa L.) occupies a unique position in global agricultural trade, prized for its distinctive aroma, superior milling recovery, and extra-long slender grains. However, simultaneously improving grain yield and premium quality attributes remains one of the most persistent challenges in basmati breeding. The present study evaluated genetic variability, trait associations, and yield-determining factors among 57 basmati rice genotypes across 18 morphological, yield, and grain quality characters during Kharif 2024 at Rice Research Station, Kaul, Chaudhary Charan Singh Haryana Agricultural University, Hisar, India. Analysis of variance revealed highly significant differences (p ≤ 0.01) among genotypes for all 18 traits, confirming a broad spectrum of heritable diversity within the experimental material. Broad-sense heritability ranged from 41.56% for flag leaf length to 96.39% for days to 50% flowering, with high heritability coupled with high genetic advance as a percentage of the mean recorded for the number of grains per panicle, number of effective tillers per plant, harvest index, plant height, and grain yield per plant, indicating predominant additive gene action and strong prospects for direct phenotypic selection. Correlation analysis revealed significant positive associations of grain yield per plant with biological yield per plant (r = 0.584), harvest index (r = 0.490), number of grains per panicle (r = 0.400), 1000-grain weight (r = 0.365), and head rice recovery (r = 0.248), whereas plant height (r = −0.349) and days to maturity (r = −0.167) showed significant negative correlations with grain yield. Path coefficient analysis identified biological yield per plant (direct effect = 0.939) and harvest index (direct effect = 0.879) as the principal direct contributors to grain yield, with a modest residual effect of 0.011, confirming that the model adequately explained yield variation. Importantly, the positive association of grain yield with milling percentage, head rice recovery, and kernel dimensions indicates that improvements in yield need not compromise grain quality. On the basis of superior grain yield and quality parameters, ten genotypes, namely HKR-17-424, HKR-15-455, HKR-17-422, PB-7, UPR 4636-18-2-1-1, CSR 301-16 BT-208, Pusa 3067-16-10-6, PAU 8484-111-1-1, CSR BT-252-19, and PB-1885, were identified as promising breeding parents for developing high-yielding, export-quality basmati cultivars.