Somatic embryogenesis and plant regeneration from petioles of Parthenocissus tricuspidata Planch.

A protocol of somatic embryogenesis and plant regeneration from petiole segments of Parthenocissus tricuspidata Planch. has been developed. Embryogenic tissue was induced on B5 (Gamborg) basal medium supplemented with 2.25-9.0 mu M 2,4-diehlorophenoxyacetic acid, 500 mg l(-1) casein hydrolysate (CH), and 0.1 g l(-1) activated charcoal. Somatic embryos were induced on B5 medium containing various concentrations of benzyladenine (BA) (4.44, 6.66, and 8.88 mu M) and alpha-naphthaleneacetic acid (NAA) (0, 0.54, and 1.61 mu M) plus 500 mg l(-1) CH. Ninety percent of normal somatic embryos were converted into plantlets directly on Murashige and Skoog (MS) medium free of plant growth regulators. Shoots could be induced from abnormal somatic embryos on MS medium containing 4.44 mu M BA, 0.05 mu M NAA, and 500 mg l(-1) CH. Genotypic differences were found in the process of somatic embryogenesis and plant regeneration. Histological analysis confirmed the process of somatic embryogenesis. Regenerated plantlets with well-developed roots were successfully acclimatized in greenhouse and all plants showed normal morphological characteristics.