High frequency induction of multiple shoots and plant regeneration from seedling explants of pigeonpea (Cajanus cajan L.)

An efficient and direct shoot bud differentiation and multiple shoot induct ion from seedling explants of pigeonpea (Cajanus cajan L.) has been achieve d, The frequency of shoot bud regeneration was influenced by the type of ex plant, genotype and concentrations of cytokinin, Explants, viz, epitocotyl, hypocotyl, leaf cotyledon and cotyledonary nodal segments from ir-day-old seedlings were cultured on MS medium augmented with different concentration s of BAP/kinetin, Among the various concentrations tested, 2.0 mg/l BAP or kinetin was found to be the best for maximum shoot bud differentiation. Per centage as well as the number of shoots per explant showing differentiation of shoot buds was higher on MS media supplemented with BAP compared to kin etin, Elongation of multiple shoots was obtained on MS medium fortified wit h BAP in combination with NAA and GA(3). The optimal BAP concentration for shoot elongation was 1.0 mg/l, The combination of 1.0 mg/l BAP with 0.1 mg/ l NAA increased the number of multiple shoots as well as shoot elongation, Addition of GA3 along with BAP and NAA combination dramatically enhanced bo th multiple shoot proliferation and shoot elongation in all the explants, T he elongated shoots were successfully rooted on MS medium containing differ ent auxins, Among them IBA at 0.2 mg/l induced maximum frequency of rooting followed by NEA and IAA. Regenerated plants were successfully established in soil where 90-95% of them developed into morphologically normal and fert ile plants, This method can thus be advantageously applied in the productio n of transgenic pigenopea plants.