Assessment of variability and genetic advance for seedling vigourtraits in rice (Oryza sativa L.) genotypes

Rice (Oryza sativa L.) is one of the most critical cereal crops, serving as a dietary staple for nearly half of the global population. Seed vigour, a key component of seed quality, plays a vital role in ensuring rapid and uniform seedling emergence and establishment, particularly under suboptimal environmental conditions. In the context of increasing mechanization and the shift towards direct seeding methods, enhancing seed vigour has gained considerable attention. The present study was conducted to assess the extent of genetic variability, heritability, and genetic advance for seedling vigour traits in rice genotypes. A total of 25 diverse rice genotypes sourced from Crop Research Station, Masodha, Banaras Hindu University, Varanasi; and ICAR–National Rice Research Institute, Orissa, were evaluated under a randomized block design with three replications during kharif 2020 and 2021 at the Seed Science and Technology Laboratory, Acharya Narendra Deva University of Agriculture & Technology. Six quantitative traits, speed of germination, germination percentage, seedling length (cm), seedling dry weight (g), vigour index-I, and vigour index-II, were recorded. Results revealed that phenotypic coefficients of variation exceeded genotypic coefficients of variation for all traits, indicating environmental influence on trait expression. High heritability estimates were observed for most traits across both years, except for speed of germination, which showed moderate heritability. High heritability estimates (ranging from 52.63% to 93.14%) were observed for most traits across both years. High heritability coupled with moderate to high genetic advance (13.86% to 27.09%) for germination percentage and vigour index-II suggests these traits are governed largely by additive gene action and can serve as reliable selection criteria for improving seedling vigour in rice breeding programs.