Physicochemical properties of seeds and oil from an F2 population of Jatropha curcas x Jatropha integerrima

Jatropha or physic nut (Jatropha curcas) is being genetically improved in many countries for commercial plantation as a source of biodiesel. This study investigates the variation in physicochemical properties of seed and oil obtained from F-2 plants of a cross between J. curcas cv. "Chai Nat" and J. integerrima (a local dwarf ornamental type from Thailand). The results revealed a high diversity in properties of seed and oil showing a number of promising genotypes. Out of 296 F2 plants derived from an F-1 plant, 42 of them showed small canopy size, high in seed yield, oil content, and oleic acid content, but low in linoleic acid content. Some plants showed a kernel to seed weight ratio of more than 0.8. Some plants had over 40% seed oil content. Phorbol ester content of their seeds varied from 0.7-4.6 mg/g, with an average of 1.9 mg/g. Seed yield of the F-2 plants showed a positive correlation with oil yield per plant (r = 0.99), while there were weak relationships between oil content with the other traits. A highly negative correlation was observed between oleic and linoleic acids (r = -0.97).