Regeneration of Jatropha curcas through efficient somatic embryogenesis and suspension culture

.Using immature zygotic embryos as explants, we have developed an efficient method for somatic embryogenesis in three germplasm accessions collected from China, India and Indonesia. Indirect somatic embryogenesis was achieved when endosperm tissue and immature embryos between 0.5-1.0 cm in length were cultured in a medium with 2,4-D, preferably at 5-10 mg/l, followed by a shift to a hormone-free medium supplemented with glutamine and asparagine. Production of secondary embryos was improved by supplementing KNO3, glutamine and asparagine. 2,4-D (0.1-0.2 mg/l). PEG 8000 (5-10%) were essential for maintenance of embryogenic calli in liquid medium. Regeneration of soil-ready plants took as short as 3 months using the suspension cultures. Over 95% of the regenerated trees were able to flower and set seeds with no discernable morphological abnormality. This regeneration method is expected to facilitate the development of more efficient transformation system for Jatropha curcas.