Genetic Variability and Character Association for Oil Yield and Its Components in Physic Nut (Jatropha curcas L.)

The need to find suitable alternative to fossil fuel necessitated the search for non-food oil crops like physic nut (Jatropha curcas L.). Improvement of the crop requires adequate knowledge of extent of genetic variability present. Therefore, a study was carried out to determine genetic variability and character association among forty local and exotic accessions of physic nut. The accessions were evaluated in two years in randomized complete block design with three replications. Results indicated highly significant variation among the accessions for all characters studied except plant height and number of seeds per fruit. High estimates of heritability were observed in number of leaves (84.10%) and seed oil (94.97%) while heritability was low in number of seeds (11.30%) and plant height (13.36%), other characters had moderate heritability. High heritability estimates were accompanied by relatively low genetic advance in all the traits except kernel oil, an indication that the character has high selection value with less environmental influence. Correlation analysis showed that tall plants produced bigger seeds because of the positive association between plant height and seed weight. Therefore, seed weight can be used as selection index.