Regeneration of Cotoneaster wilsonii Nakai through Indirect Organogenesis

Abstract

The ornamental plant Cotoneaster wilsonii Nakai is a rare endemic species to the Ulleung Island in Korea. There is an urgent need to develop efficient propagation methods to preserve this endangered plant species. The cytokinin thidiazuron (TDZ) at a concentration of 0, 1.0, 2.0, or 3.0 mg center dot L-1 combined with 0, 0.5, 1.0, or 1.5 mg center dot L-1 a-naphthaleneacetic acid (NAA) was used to induce calli from young leaf explants on the Murashige and Skoog (MS) medium. The TDZ and/or 6-benzyladenine at a concentration of 0, 0.5, or 1.0 mg center dot L-1 combined with 0.2 mg center dot L-1 NAA was supplied to the MS medium to induce shoots from calli. Four auxins at 0, 0.2, 0.4, 0.6, 0.8, or 1.0 mg center dot L-1 were supplied to half-strength MS medium for root induction. The treatment of TDZ at 1.0 mg center dot L-1 combined with 1.5 mg center dot L-1 NAA not only had 100% callus induction ratio, but also induced the heaviest calli. The shoot induction ratio was the greatest with TDZ at 1.0 mg center dot L-1, and the greatest root induction ratio was obtained with IAA at a concentration of 0.8 mg center dot L-1. In conclusion, an effective indirect organogenesis system was established for C. wilsonii Nakai.