~ 1386 ~ International Journal of Chemical Studies 2021; 9(1): 1386-1389 P-ISSN: 2349–8528 E-ISSN: 2321–4902 www.chemijournal.com IJCS 2021; 9(1): 1386-1389 © 2021 IJCS Received: 06-11-2020 Accepted: 14-12-2020 M Sri Lakshmi Department of Genetics and Plant Breeding, Agricultural College, Bapatla, Andhra Pradesh, India Y Suneetha Agricultural Research Station, Bapatla, Andhra Pradesh, India T Srinivas Department of Genetics and Plant Breeding, Agricultural College, Bapatla, Andhra Pradesh, India Corresponding Author: Y Suneetha Agricultural Research Station, Bapatla, Andhra Pradesh, India Genetic diversity analysis for grain yield and yield components in rice M Sri Lakshmi, Y Suneetha and T Srinivas DOI: https://doi.org/10.22271/chemi.2021.v9.i1t.11416 Abstract The present investigation was undertaken with 82 rice genotypes to estimate genetic divergence of the genotypes for yield and yield components. The study involved 70 genotypes from Maruteru, six from Machilipatnam, three from Bapatla, two from Phillippines and one from Pulla. The diversity was evaluated using multivariate analysis technique of Mahalanobis D 2 . The 82 rice genotypes studied were grouped into ten clusters. Cluster IV was observed to be the largest with 22 genotypes, followed by Cluster I with 17 genotypes and Cluster V with 13 genotypes. The clusters, VII, VIII, IX and X were monogenotypic. The pattern of distribution of genotypes into various clusters was observed to be at random with no relation to geographical diversity. Results on inter-cluster distances revealed maximum diversity between genotypes of cluster IX and cluster X, while intra-cluster distance was noticed to be maximum for cluster V. Cluster III had recorded maximum grain yield per plant. Further, maximum contribution towards genetic divergence was noticed by filled grains per plant (47.03%), followed by ill- filled grains per plant (21.92%) and minimum by days to 50 per cent flowering (0.01%). Keywords: Rice, genetic divergence, grain yield and yield components Introduction Genetic divergence studies play a key role in analyzing of genetic diversity among the genotypes and aid in the selection of diverse parents towards realization of enhanced levels of heterosis in addition to wide range of variability for effective selection. Multivariate analysis like Mahalanobis D 2 statistic provides an useful tool for measuring the genetic diversity in a given population with respect to different characters considered together. Further, the problem of selecting diverse parents for hybridization programme is narrowed with the identification of characters responsible for discrimination between the genotypes. This is essential in major crops like rice, a source of food for about three million people worldwide to break the yield plateaus being observed in the crop. The present investigation was undertaken in this direction to estimate genetic diversity of rice genotypes studied for their utilization in crop improvement programs aimed at the development of high yielding rice varieties. Material and Methods The experimental material consisted of 82 rice genotypes obtained from Regional Agricultural Research Station, Maruteru (70 Nos.); Agricultural Research Station, Machilipatnam (6 Nos.); Agricultural Research Station, Bapatla (3 Nos.), International Rice Research Institute, Philippines (2 Nos.) and Agricultural Research Station, Pulla (1 No.). All the 82 genotypes were sown at Regional Agricultural Research Station, Maruteu during Rabi 2016-17 on separate raised nursery beds. All recommended package of practices were adopted to raise a healthy nursery and thirty days old seedlings were transplanted in the main field laid out in Randomized Block Design (RBD) with three replications. Each genotype was transplanted separately in three rows of 2m length by adopting a spacing of 20 cm between rows and 15 cm between plants. All recommended package of practices were adopted throughout the crop growth period and need based plant protection measures were taken up to raise a healthy crop. Observations were recorded on five randomly selected plants for grain yield per plant and yield component characters, namely, plant height, total tillers per plant, ear bearing tillers per plant, panicle length, filled grains per panicle and ill-filled grains per panicle. Observations on days to 50 per cent flowering and days to maturity were recorded on plot basis.