IN VITRO REGENERATION OF DAVIDIA INVOLUCRATE BAILL.

Abstract

Davidia involucrata Baill, dove tree, is a beautiful ornamental plant species with dove-like flowers. However, the supply is limited and the plant is listed as an endangered species in China due to its reproductive difficulties. In vitro culture conditions for Dove Tree regeneration was investigated. Hibernaculum explants were collected from adult Davidia involucrata and cultured on different media. Orthogonal experiment designs were used to study the optimum medium. The basal media were Murashige and Skoog (MS), 1/2MS, N6, and Woody Plant Medium (WPM). The plant growth regulators were 6-benzyladenine (BA), Zeatin (ZT) and 1-naphthalene acetic acid (NAA). The results showed that, although hibernaculum explants could be cultured on all four media types, the most effective medium for proliferation was WPM medium with 2.0 mg L -1 BA and 0.1 mg L -1 NAA. The induction rate was 92.3%. The excision of node segments from the in vitro-derived shoots and their subsequent culture on WPM supplemented with 3.0 mg L -1 BA and 0.1 mg L -1 ZT enhanced adventitious bud proliferation. Three to six new adventitious buds were regenerated from each node. The effect of 4 basal media to rooting from high to low was: WPM>1/2MS> N6>MS. NAA was better than IBA and BA had a repressive effect to rooting. Addition of activated carbon at 0.5 g L -1 was beneficial for rooting of Davidia involucrata Baill. The average 3.6 roots per shoot were observed after 4 weeks. Rooted plants were transferred to small pots and the survival rate reached 73.3%. Acclimated plantlets of dove tree in the greenhouse were successfully transferred to field conditions and the survival rate was 76%.