Studies on genetic variability for lodging related traits in rice (Oryza sativa L.)

Genetic variability, heritability and genetic advance were estimated for various traits in relation to lodging in 80 genotypes of rice. Preliminary results indicate highly significant (P<0.01) differences for all traits studied thereby indicating the presence of genetic diversity among these accessions. The results revealed high range for plant height (19.49-66.8 cm), lodging percentage (1.74-62.66) and total tillers per meter length (54.5-180). The genotypic and phenotypic coefficient of variations (PCV and GCV) were maximum for lodging percentage (PCV=49.98, GCV=49.06) and minimum for days to maturity (PCV=3.17, GCV=2.91). The phenotypic coefficients of variations were higher than those of genotypic coefficients of variations, which indicate influence of environment for expression of the characters. High estimates of h2 (bs) were obtained for all the character studied. The highest value of heritability h2 was obtained for 1000 grain weight (97.45), plant height (96.49) and lodging percentage (96.33). In the present study, total tillers per meter length recorded maximum genetic gain (44.93). High heritability along with high genetic gain was observed for lodging percentage (h2=96.33, GA=64.84), plant height (h2=96.49, GA=22.4), productive tillers per meter (h2=92.19, GA=42.91), non-productive tillers per meter (h2=78.45, GA=10.35) and total tillers per meter length (h2=90.57, GA=48.93). Therefore, improvement of these characters could be brought about by practicing phenotypic selection in desired direction.