An Efficient Regeneration System for Pigeonpea (Cajanus cajan L.)

Pigeonpea is an important protein rich legume food crop grown in marginal environments of the world. Environmental stress, pests and disease cause massive yield losses due to limited genetic diversity of pigeonpea in the primary gene pool. Genetic manipulation is becoming an important method for pigeonpea improvement. In the present study, a reproducible and highly efficient plant-regeneration protocol in pigeonpea varieties, viz., 'Phule Rajeshwari' and 'Vipula' was developed. Multiple shoot induction was achieved using leaf and apical meristem with attached leaf as explant by use of various concentrations and combinations of growth regulators. Optimum embryogenic callus induction from leaf explant was observed on Murashige and Skoogs medium supplemented with 2.0 mg/l thidiazuron. Apical meristem with attached leaf explants showed early shoot initiation, high frequency of callusing (100%), and shoot regeneration (100%) as compared with leaf explant in both varieties. In vitro rooting (93.33%) was obtained within 10 days on MS medium supplemented with 2.0 mg/l indole butyric acid. The in vitro rooted plantlets were successfully established in polycarbonated polyhouse with 80% survival rate. This optimized regeneration protocol can be efficiently used for genetic transformation in pigeonpea.