GENETIC VARIABILITY AND DIVERSITY IN AROMATIC RICE

Abstract

Genetic variability and diversity are prerequisite for any crop improvement program as it helps breeders in the selection. For this purpose the field experiment was conducted at the research field of Hajee Mohammad Danesh Science and Technology University (HSTU); in the Department of Genetics and Plant Breeding, in July of 2016, to investigate genetic variability and diversity of twenty aromatic rice genotypes with a view to assess the superior genotype in future hybridization program for developing new rice varieties that is suitable for the target environment. This analysis assess the variability and diversity of the genetic base with respect to agro-morphological features with special reference to twelve quantitative traits like plant height, panicle length, panicle weight, 1000-grain weight, maturity, number of fertile grains per panicle, grain yield per hill etc. Analysis of variance for each traits showed significant differences among the varieties. In general phenotypic coefficients of variation (PCV) estimates were higher than genotypic coefficients of variation (GCV) estimates for all the studied characters in all genotypes, displaying the influence of environmental effect on the studied characters. High heritability associated with high genetic advance in percent of mean (GAM) was observed for panicle weight, harvest index,1000- grain weight, plant height, sterility percent, productive tillers per hill, panicle length, fertile grains per panicle, grain yield per hill; which indicated that selection for these characters would be effective. Character association of the yield attributing traits revealed significantly positive association of grain yield with harvest index, panicle length, panicle weight, 1000-grain weight. Multivariate analysis with the grouping of twenty rice genotypes into four clusters based on Euclidean cluster analysis with cluster II containing the maximum of eight genotypes. Maximum intra-cluster distance was observed in cluster II and Maximum inter-cluster distance was recorded between clusters I and II followed by clusters III and IV suggesting that the genotypes constituted in these clusters had wide genetic diversity and may be used as parents for future hybridization programme. Cluster mean analysis revealed that cluster II having highest mean value for all the yield contributing trait viz. panicle length (cm), fertile grains per panicle, panicle weight (g), 1000- grain weight, grain yield per hill (g) and harvest index. PCA findings revealed that the first four principal components accounted for 85.20% of the total variation. Total outcome suggested that plant height, productive tillers per hill, grain yield per hill, harvest index of the genotypes Kalojira, BRRI 49, Radhuni pagol, Malshira, Paijam were helpful.