Genetic Variability, Character Association and Path Analysis in Jatropha Curcas

Sixteen Jatropha curcas genotypes collected from four states were grown in randomized block design and evaluated for 12 characters. The genotypes showed significant differences in most component traits and seed yield, excepting primary branches/plant, fruits/bunch and seeds/fruit. The genotypes Utkal nursery, Phule1, IST 1, Jodhpur1 and Chhatrapati had above average (>84.7 g) seed yield/plant. Phenotypic coefficient of variation (PCV) & genotypic coefficient of variation (GCV) estimates were high for seed yield/plant followed by flowering bunches/plant, fruits/plant and secondary branches/plant. Heritability was high (>80%) for plant height, fruits/plant and 100 seed weight. Genetic advance (GA) was high (>50%) for seed yield/plant, fruits/plant and flowering bunches/plant. Moderate to high heritability accompanied with high genetic advance for seed yield/plant, fruits/plant and flowering bunches/plant indicated additive gene action and selection for these characters would be effective. Fruits/plant, flowering branches and bunches/plant, collar diameter and secondary branches/plant had high positive correlation with seed yield/plant. Flowering bunches/plant and fruits/plant had high positive direct effect on yield and indirect positive effect via these two traits greatly influenced positive association of other traits with yield. Seeds/fruit and 100 seed weight had moderate positive direct effect on yield. The remaining seven component traits had very low direct effect on yield. The character association and path analysis study revealed that selection for flowering bunches/plant and fruits/plant would be highly effective in bringing out improvement in yield. Selection for seeds/fruit and 100 seed weight would result in some improvement in yield. Thus, the ideotype to achieve high yield in Jatropha should have more number of flowering bunches/plant and fruits per plant and moderate to high value for seeds/fruit and 100- seed weight.