Assessment of Genetic Variability, Heritability and Genetic Advance among Red Rice (Oryza sativa L.) Genotypes of Himachal Pradesh, India

Abstract

The present study was undertaken to assess genetic variability, heritability and genetic advance and among 43 germplasm lines of red rice (Oryza sativa L.) sourced from various districts of Himachal Pradesh under field conditions at the experimental farm of Rice and Wheat Research Centre, Malan during the Kharif season of 2021. The experiment was laid out in a randomized block design with three replications. Twelve agronomic traits were evaluated, including phenological, morphological, and yield-related characters. Significant genotypic differences were observed for all traits except flag leaf width, indicating ample amount of genetic variability in the material under study. Notably, moderate to high and phenotypic and genotypic coefficients of variation were observed for key traits such as flag leaf length (19.93 and 17.14, respectively), flag leaf width (21.21 and 14.83, respectively), total tillers per plant (21.63 and 20.95, respectively), effective tillers per plant (21.82 and 18.21, respectively), spikelet per panicle (26.78 and 22.52, respectively), 1000 grain weight (16.63 and 16.14, respectively), biological yield per plant (21.43 and 18.10, respectively), harvest index (19.46 and 14.96, respectively) and grain yield per plant (21.43 and 18.10, respectively). Heritability in broad sense was high (>80%) for days to 50 per cent flowering (95.63), days to 75 per cent maturity (82.89), total tillers per plant (93.82), 1000 grain weight (94.23) and grain yield per plant (83.87). Expected genetic advance, expressed as percentage of the mean was high (>20%) for most traits viz., flag leaf length (30.38), flag leaf width (21.36), total tillers per plant (41.80), effective tillers per plant (31.23), spikelets per panicle (38.95), 1000 grain weight (32.28), biological yield per plant (31.50), harvest index (23.68) and grain yield per plant (59.37). High heritability coupled with high genetic advance was recorded for several traits, including total tillers per plant (93.82%, 41.80%, respectively), 1000 grain weight (94.23%, 32.28%, respectively) and grain yield per plant (83.87%, 59.37%, respectively) indicating the predominance of additive gene action and scope for effective selection for these traits. These findings suggest that seed yield and its contributing traits could serve as reliable selection indices in the breeding programs, providing valuable insights for the development of improved cultivars with higher productivity and desirable agronomic characteristics.