Factors affecting regeneration of pigeonpea (Cajanus cajan L-Millsp) from mature embryonal axes

Regeneration of viable plants was obtained via organogenesis from mature em bryonal axes explants of pigeonpea. Shoots were produced from the apical re gion of embryonal axes after 20 days of dark incubation on modified Murashi ge and Skoog (1962) medium containing 8.86 mu M benzylaminopurine (BAP) and 1.07 mu M alpha-naphthalene acetic acid (NAA). When the explants were cult ured under light-dark (16-8 hrs) conditions, shoots were initiated only aft er 65 days of culture initiation. The explants lost their ability to regene rate plantlets when they were cultured in continuous light. Regenerated sho ots elongated either in the same medium or in MS basal medium. About 40% of the elongated shoots sequentially produced simple, bifoliate and finally t rifoliate leaves instead of producing trifoliate leaves directly. The elong ated shoots were rooted efficiently upon transferring them to half strength MS medium supplemented with 2.41 mu M indole-3-butyric acid (IBA). Rooted plantlets were successfully transferred to soil after hardening.