High frequency plant regeneration from cotyledon and hypocotyl explants of ornamental kale

摘要

A high frequency shoot regeneration system for ornamental kale [Brassica oleracea L. var. acephala (D.C.) Alef.] was firstly established from seedling cotyledon and hypocotyl explants. The ability of cotyledon and hypocotyl to produce adventitious shoots varied depending upon genotype, seedling age and culture medium. The maximum shoot regeneration frequency was obtained when the explants from cv. Nagoya 4-d-old seedlings were cultured on Murashige and Skoog (MS) medium supplemented with 3 mg dm−3 6-benzylaminopurine (BA) and 0.1 mg dm−3 naphthaleneacetic acid (NAA). The frequency of shoot regeneration was 65.0 % for cotyledons, 76.1 % for hypocotyls; and the number of shoots per explant was 4.3 for cotyledons, 8.2 for hypocotyls. Hypocotyl explants were found to be more responsive for regeneration when compared with cotyledons. Among the 4 cultivars tested, Nagoya showed the best shoot regeneration response. The addition of 3.0 mg dm−3 AgNO₃ was beneficial to shoot regeneration. Roots were formed on the base of the shoots when cultured on half-strength MS medium. Additional key words AgNO₃ - auxin - Brassica oleracea var. acephala - cytokinin - genotype - rooting - shoot regeneration Acknowledgements: This research was supported by a grant from the Ministry of Agriculture of China (2003-Z036). We thank all the colleagues from our laboratory, both present and past, for constructive discussions.