High-frequency plant regeneration from leaf-disc cultures of Jatropha curcas L.: an important biodiesel plant

A simple, high-frequency and reproducible protocol for induction of adventitious shoot buds and plant regeneration from leaf-disc cultures of Jatropha curcas L. has been developed. Adventitious shoot buds were induced from very young leaf explants of in vitro germinated seedlings as well as mature field-grown plants cultured on Murashige and Skoog's (MS) medium supplemented with thidiazuron (TDZ) ($2.27{\mu}M$), 6-benzylaminopurine (BA) ($2.22{\mu}M$) and indole-3-butyric acid (IBA) ($0.49{\mu}M$). The presence of TDZ in the induction medium has greater influence on the induction of adventitious shoot buds, whereas BA in the absence of TDZ promoted callus induction rather than shoot buds. Induced shoot buds were multiplied and elongated into shoots following transfer to the MS medium supplemented with BA ($4.44{\mu}M$), kinetin (Kn) ($2.33{\mu}M$), indole-3-acetic acid (IAA) ($1.43{\mu}M$), and gibberellic acid ($GA_3$) ($0.72{\mu}M$). Well-developed shoots were rooted on MS medium supplemented with IBA ($0.5{\mu}M$) after 30 days. Regenerated plants after 2 months of acclimatization were successfully transferred to the field without visible morphological variation. This protocol might find use in mass production of true-to-type plants and in production of transgenic plants through Agrobacterium/biolistic-mediated transformation.