Assessment of Genetic Diversity in Rice (Oryza sativa L.) Genotypes for Grain Yield Characters

A set of 55 genotypes of rice were evaluated for “assessment of genetic diversity in rice genotypes for grain yield characters”. The experiment was conducted in a Randomized Block Design with three replications during the kharif season, of 2021 at Naini Agriculture Institute, Naini. The plant to plant distance was 15 cm and row to row distance was 20 cm. The data were recorded from five randomly selected plants for each genotypes from all the replicates for thirteen characters. Analysis of variance showed significant differences among genotypes for all 13 characters indicating that the material has adequate genetic variability to support the breeding programme for improving the grain yield of rice. Out of 55 rice genotypes evaluated for various characters, 5 genotypes were found superior for different characters. These 5 genotypes were found better for more than one character. Among the lines SHUATS DHAN -6 (62.133g) recorded the highest grain yield per hill followed by the genotypes BPT-3291 (51.8g), SHIATS Dhan -2 (51.467g), SIGNET-5455 (50.467g) and SIGNET-5455 (50.4). All these genotypes were significantly higher as compared to the check NDR - 359 (CHECK) (22.67g). High estimate of heritability coupled with high genetic advance as percent of mean was recorded for Grain yield per hill, Biological yield, Number of spikelets per panicle, Harvest Index, Flag leaf length, Number of tillers per hill, Number of panicles per hill, Flag leaf width, Test weight, and Plant height. These traits are governed by additive gene effects and therefore, may be improved through direct selection. Further the characters viz., Biological yield, Harvest Index, Number of tillers per hill, Days to fifty percent flowering, Flag leaf length and Test weight, had the highest direct positive effect and  indirect effect (through each other) on grain yield per hill. Thus, selections for these characters will prove efficient for the improvement of grain yield of rice. All the 55 rice genotypes were  classified using Mahalanobis D2 statistics involving 13 quantitative characters of 55 genotypes grouped into 6 clusters In the present study, the highest inter cluster distance was observed between cluster IV and cluster V (368.37) followed by cluster II and cluster V (361.04).