Characterizing Grain Quality and Breeding Implications in Rice Genotypes Across Cropping Durations

The research was conducted at the Pandit Jawaharlal Nehru College of Agriculture and Research Institute during the Zaid season of 2024 to assess genetic diversity in grain quality among 44 rice genotypes, including landraces and varieties across cropping durations. A Randomized Block Design was used to evaluate grain quality and nutrient traits. Significant genetic variability was observed, especially in traits like the linear elongation ratio, supporting targeted breeding. High heritability and genetic advance in two traits indicated the potential for improvement through selection-based methods like pedigree breeding. Correlation analysis revealed significant positive associations among quality traits such as linear elongation ratio and elongation index, enabling effective selection. Genetic diversity analysis grouped genotypes into four clusters, with Clusters III and IV containing superior landraces for grain size, water absorption, and cooking quality. Principal component analysis highlighted elongation and kernel traits as key contributors to variation, validating clustering patterns and guiding parent selection. Using the Smith-Hazel index, top-performing genotypes across durations were identified. Rakthasali excelled in short-duration cropping, while Thanga samba and Rasakadam showed superior performance in medium and long durations, respectively. Nutrient analysis showed higher iron and zinc in brown rice, with Rasakadam, Thanga samba, and Rasakadam again emerging as nutrient-rich genotypes. Organoleptic evaluation identified seven genotypes with good palatability. Overall, this study offers valuable insights into the grain and nutritional quality diversity of rice genotypes, aiding the formulation of effective breeding strategies to improve rice quality.