GENETIC VARIABILITY, CORRELATION AND CLUSTER ANALYSIS IN ELITE LINES OF RICE

Development of rice cultivars with appreciative performance is one of the prime objectives of rice breeding programs. In this regard, the current experiment was conducted during 2016 at Agricultural Research Institute, Dera Ismail Khan, Khyber Pakhtunkhwa, Pakistan. The aims of the study were to generate scientific information on nature and magnitude of genetic variability and relationship of yield and related attributes and to classify genotypes into distinct clusters on the basis of quantitative traits. Fourteen elite rice genotypes were evaluated following randomized complete block design with three replications. Analysis of variance manifested significant (P ≤ 0.01) differences among genotypes based on the studied triats viz., panicle emergence, flag leaf area, effective tillers plant-1, panicle length, primary branches and grains panicle-1, 1000 grain eight and paddy yield plot-1, except physiological maturity. The magnitudes of PCV and GCV were higher (>20%) in all the studied traits, except physiological maturity, reflecting wide spectrum of variability and offering greater opportunities for selection. Similarly, the magnitude of broad-sense heritability and genetic advance as percent of mean was moderate to high for majority of traits, indicating additive gene action in their inheritance hence, amenable for simple selection. Correlation analysis revealed that paddy yield manifested significantly positive correlation with physiological maturity (r = 0.46**) and negative correlation with 1000-grain weight (r = -0.30*). The dendrogram grouped 14 rice genotypes into four clusters. Cluster IV incorporated the highest number of genotypes, which also had highest cluster mean for paddy yield. Therefore, prominence should be given to genotypes aggregated in cluster IV that having high yield potentiality. Based on mean performance, Irrigated-04, E-93, E-94 and E-107 showed superiority in respect of paddy yield and some other traits, hence these lines could be recommended for varietal development.