Genetic divergence in 3 and 4 year old genotypes of physic nut [Jatropha curcas (L.)]

Fifty six germplasm lines of physic nut collected from Aravali hills of Southern Rajasthan were assessed for 26 characters recorded for two consecutive years during 2007 and 2008 on 3 and 4 year old plants. The values of V statistics were 12040 and 10950 in first and second year, respectively which showed significant difference between the genotypes over the characters. The two year values indicated that sufficient diversity was present among the 56 genotypes of physic nut. The 56 genotypes were grouped into 8 clusters using Euclidean(2) values of 500 and 285 in the third and fourth year, respectively. The composition of clusters was slightly different in different years. With changing the age, genotypes also changed their cluster but most of the genotypes moved together and found place in one cluster. There was no relationship between genetic diversity and geographic distance. The contribution of vegetative characters towards genetic divergence was negligible. The characters like seed content, 100-seed weight, number of female flowers per inflorescence, oil content, kernel: shell ratio and weight per fruit were main contributors to total divergence. Cluster III and VIII in 3rd year and cluster VI and VIII in 4th year had maximum inter cluster distances. Cluster IV in 3rd year and cluster VIII in 4th year had highest mean values for maximum number of characters. Based on above results ARV-036 X ARV-020 and ARV-036 X ARV-023 are recommended for hybridization, as these genotypes showed good per se performance for seed yield and oil content and belong to the highly diverse clusters.