Somatic embryogenesis and shoot organogenesis from interspecific hybrid embryos of Vigna glabrescens and V. radiata

Abstract

Somatic embryogenesis occurred on cotyledons of morphologically abnormal embryos derived from Vigna glabrescens x V. radiata crosses and cultured on Murashige and Skoog (MS) medium without growth regulators. The frequency of 15–17 day old embryos that gave rise to somatic embryos increased from 8% to 29% by application a mixture of 100 mg/l gibberelllc acid, 25 mg/l α-naphthaleneacetic acid (NAA) and 5 mg/l kinetin daily to the pedicels of the develo** pods. However, only callus formed on immature hybrid embryos of the reciprocal cross. These callus tissues occasionally gave rise to shoots via organogenesis when transferred to MS medium with 2 mg/l N⁶-benzyladenine and 0.05 mg/l NAA. Treatment of pods with growth regulators did not influence the frequency of organogenic callus. Selfed embryos of the parents did not form somatic embryos in culture, nor did callus derived from the selfed embryos produce shoots. Thus, the ability to redifferentiate appears to be associated with interspecific hybridity.