Explants selection for in vitro propagation of Pachyrhizus erosus L.

Pachyrhizus erosus tuber is rich in protein asides its agronomical value as a legume, but the seeds by which it is propagated have very low viability. This study established sterilization protocol and effect of various concentrations of auxins and cytokinins on callus production and shoot regeneration from explants of P. erosus. Explants and seeds were sterilized using sodiumhypochlorite (NaClO) solution (5, 10 and 15% v/v) for 5 and 10 mins. Nodal, stem and leaf explants from in vitro germinated P. erosus and tuber from field grown plant were sterilized and cultured on Murashige and Skoog (MS) medium (control) and MS combined with different concentrations of auxins (NAA and 2, 4-D) and cytokinin (BA and Kinetin) and the cultured explants were monitored in terms of degree of callus formation, morphology and colour of callus and also for shoot induction. The results showed that seeds of P. erosus sterilized with 10% NaClO solution for 10 mins and germinated in vitro is the best way of getting sterile nodal, stem and leaf explants for the in vitro propagation of the plant, while tuber explants could be sterilized with 15% NaClO for 10 minutes. Nodal explants inoculated in MS medium supplemented with 1.0 mg/L BA gave the highest shoot regeneration response, while stem explants inoculated on MS medium supplemented with 1.0 mg/L BA and 0.5 mg/L NAA also gave the highest amount of friable callus. The study concluded that in vitro germinated seeds were the best way of getting explant for P. erosus.