Efficient plant regeneration in vitro from cotyledon explants of chieh-qua (Benincasa hispida Cogn. var. chieh-qua)

Abstract

An efficient plant regeneration system for Benincasa hispida Cogn. var. chieh-qua was developed using explants isolated from mature seeds germinated on moist filter paper under aseptic conditions for 3 days in the dark and 2 days under light. Shoot regeneration frequency (percentage of explant-forming shoots) was about 90% when the proximal cotyledon portion with a 1 mm-long hypocotyl segment was first cultured on Murashige and Skoog (MS) medium supplemented with 6.0 mg/l benzylaminopurine (BA) and 0.2 mg/l naphthalene acetic acid (NAA) for 4 days and then transferred to MS medium containing 1 mg/l BA for 4 weeks. About 80% of the regenerated shoots could elongate further. The root induction medium was half-strength MS medium with 0.01 mg/l NAA and 0.01 mg/l BA. The average rooting frequency was about 93%.