Callus induction and plant regeneration from leaf explants of jojoba [Simmondsia chinensis (Link) Schneider]

An efficient micropropagation protocol involving callus induction and shoot regeneration has been standardized in Simmondsia chinensis, an oil yielding, medicinal and multipurpose plant species. Higher percent of callus proliferation (97.3%) was obtained from leaf explants, taken from field grown mature plant, when cultured on MS medium supplemented with 2,4-D (2.0 mg L-1)+BAP (0.5 mg L-1)+CH (100 mg L-1) within 20-22 d of inoculation. The callus was yellowish green in colour and soft in texture. Further, optimum shoot regeneration was obtained from the leaf derived callus on MS medium fortified with BAP (2.0 mg L-1)+NAA (0.5 mg L-1)+GA(3) (0.3 mg L-1). About 92% cultures responded with an average number of 9.1 shoots per culture. The shoots obtained via callogenesis were rooted on half-strength agar-solidified MS medium supplemented with IBA (1.0 or 2.5 mg L-1). The medium containing 2.5 mg L-1 IBA was the best for rooting of shoots. The rooted shoots were transplanted to soil with 75% success. The protocol will be of immense importance in rapid mass multiplication of elite germplasm, as well as for conservation of this important species.