In Vitro Direct Regeneration through Cotyledon Culture in Pigeon Pea [Cajanus Cajan (L.) Millsp.] and Evaluation of Genetic Fidelity using RAPD Markers

An efficient and direct in vitro regeneration of Cajanus cajan (red gram) cv ICP 26 from cotyledon explants was established. Cotyledons of 7–8 day old in vitro grown seedlings were cultured on MS/B₅ medium augmented with different concentrations (0.5–5.0 mg/L) of 6-benzylaminopurine (BAP)/Kinetin (KIN). Among these concentrations, 2.0 mg/L BAP was found to be efficient in inducing maximum number of multiple shoots with 80% of response. 80% of the elongated shoots were successfully rooted on MS medium fortified with 1.0 mg/L indole-3-butyric acid (IBA). These in vitro rooted plantlets were successfully established in soil where 8090% of them developed into normal and fertile plants. 20 RAPD primers were used to assess the genetic fidelity of randomly selected regenerated plantlets along with the donar plant. Out of 20 RAPD primers screened only 7 primers produced clear, distinct and scorable bands with an average of 2.5 bands per primer. All banding profiles from regenerated plantlets were monomorphic and similar to those of the mother plant. The amplification pattern confirmed the genetic uniformity of the regenerated plantlets. Thus, this reproducible regeneration protocol can be used for Agrobacterium tumefaciens mediated genetic transformation in pigeon pea.