In vitro regeneration from node and leaf explants of Jatropha curcas L. and evaluation of genetic fidelity through RAPD markers

Plantlet regeneration in Jatropha curcas L. (Family: Euphorbiaceae), an energy shrub, has been studied from nodal and leaf explants on basal MS medium. The nodal explants were found superior to leaf explants. Higher shoot bud differentiation was observed on MS media supplemented with 8 mu M N-6-benzyladenine (BA; 6.2 +/- 0.83) from nodal explants in comparison to both 10 mu M kinetin (Kn; 2.8 +/- 0.45) from leaf explants and a combination of 6.0 mu M BA with 4.0 mu M Kn (5.0 +/- 0.71) from nodal explants. MS medium fortified with 8 mu M BA and 2 mu M IBA (indole butyric acid) was found most suitable for both callus mediated organogenesis and elongation of shoots. Addition of 45 mu M adenine sulphate, 15 mu M glutamine and 10 mu M proline to this optimized MS medium enhanced the number of multiple shoot proliferation (9.8 +/- 0.84) per explant and elongation at the end of 2nd wk. The elongated shoots were successfully rooted on half-strength MS medium with a prior incubation on MS medium with NAA (alpha-napthalene acetic acid) or IBA or a combination of both; 2 mu M IBA provided better response for rhizogenesis among them. Regenerated plantlets were successfully established in soil where 80 +/- 4% of them developed into morphologically normal and fertile plants. Forty RAPD decamer primers were used to assess genetic fidelity of regenerated plantlets along with the donor plant. Fourteen primers responded for amplification, generating 75 amplified products (160 to 2690 bp). The amplification pattern confirmed the genetic uniformity of the regenerated plantlets and substantiated the efficacy and suitability of this protocol for in vitro propagation of J. curcas, thereby favouring the economics of the cost of plant material and time factor.