EVALUATION OF CASTORBEAN (RICINUS COMMUNIS L.) MUTANTS FOR GENETIC PARAMETERS AND CLUSTER ANALYSIS

Abstract

Twenty seven desirable mutants of castorbean were evaluated in M5 generation at Nuclear Institute for Agriculture and Biology, Faisalabad, Pakistan during 2007-08. Estimation of different genetic parameters alongwith correlation coefficient, path and cluster analyses were done in castorbean mutants on quantitative traits. The results showed positive and significant genotypic correlation of main spike length, capsules of main spike, capsules of secondary spike and spikes per plant with seed yield. These traits alongwith branches per plant also showed positive but non-significant phenotypic correlation with seed yield. Days to mature, number of branches and capsules of main spike showed positive direct effects coupled with positive genotypic correlation with seed yield. Therefore, direct selection of these characters might be helpful for increasing seed yield. Plant height showed high heritability(bs) (54%) alongwith high genetic advance (19.87) seemed to be governed by additive genes while days to mature exhibited high heritability(bs) (45.10%) with low genetic advance (6.61) governed by non-additive type of genes (dominants, epistasis or their interaction). Complete linkage elucidea- distances classified the population into three main clusters. Cluster-II showed maximum average seed yield (187.50 g/plant) followed by cluster I (138.78 g/plant). The variation (standard deviation) was also higher in cluster-II (20.84). The high average seed yield (187.50 g/plant) in cluster-II was due to high average values of main spike length (50.29 cm), secondary spike length (33.81 cm), capsules of main spike (135.21), capsules of secondary spikes (74.13) and spikes per plant (7.94) as compared to other two clusters. Aforementioned characters also showed positive and significant correlation with seed yield. So mutant lines possessing more number of branches, more number of spikes and higher number of capsules in main as well as secondary spikes may be promoted further for increasing seed yield.