Micropropagation of several Japanese woody plants for horticultural purposes

Axillary buds of 43 Japanese broad-leaved species were collected and used to initiate micropropagation cultures. Four nutrient media (MS, DKW, WPM, A3) were tested with different combinations of growth regulators (BAP or 2iP alone or together with IBA or IAA). Ten species (Callicarpa dichotoma (Lour.) K. Koch, Chosenia arbutifolia (Pallas) B. V. Skvortz., Lonicera chamissoi Bunge, Maackia amurensis Rupr. & Maxim., Morus alba L., Populus maximowiczii Henry, Prunus nipponica Matsum., Ribes japonicum Maxim., Salix sachalinensis F. Schmidt, Toisusu urbaniana (Seemen) Kimura) produced shoot cultures which could be used for micropropagation of numerous plantlets. The shoots were rooted on IBA supplemented medium and transplanted to a peat-sand mixture; most of them survived under the greenhouse conditions. Many species have survived the following winters out of doors, but some of them have shown cold damage. It is apparent that the long-day conditions in south Finland (60°N) affect the development of dormancy of Japanese woody plants (Hokkaido 42—43°N), but some of them may be used for horticultural purposes.