Shoot regeneration from cotyledonary leaf explants of Jatropha curcas: a biodiesel plant

Abstract

A simple, high frequency, and reproducible method for plant regeneration through direct organogenesis from cotyledonary leaf explants of Jatropha curcas was developed using Murashige and Skoog (MS) medium supplemented with different concentrations of thidiazuron (TDZ) or 6-benzyl aminopurine (BAP). Medium containing TDZ has greater influence on regeneration as compared to BAP. The induced shoot buds were transferred to MS medium containing 10 mu M kinetin (Kn), 4.5 mu M BAP, and 5.5 mu M a-naphthaleneacetic acid (NAA) for shoot proliferation. The proliferated shoots could be elongated on MS medium supplemented with different concentrations and combinations of BAP, indole-3-acetic acid (IAA), NAA, and indole-3-butyric acid (IBA). MS medium with 2.25 mu M BAP and 8.5 mu M IAA was found to be the best combination for shoot elongation. However, significant differences in plant regeneration and shoot elongation were observed among the genotypes studied. Rooting was achieved when the basal cut end of elongated shoots were dipped in half strength MS liquid medium containing different concentrations and combinations of IBA, IAA, and NAA for 4 days, followed by transfer to growth regulators free half strength MS medium supplemented 0.25 mg l(-1) activated charcoal. Elongated shoot treated with 15 mu M IBA, 5.7 mu M IAA, and 11 mu M NAA resulted in highest percent rooting. The rooted plants could be established in soil with more than 90% survival rate. The method developed may be useful in improvement of J. curcas through genetic modification.