Abstract
We have collected Japanese beech trees (Fagus crenata) superior in growth and stem straightness in Tohoku area by graft multiplication. In this process, difficulties in providing enough count of rootstocks every year raised from its specific characteristic called masting (fruit yield oscillate each year, and abundant harvest year comes only once 5 to 7 years). Most of the unpreserved lines are localized so apart to access in winter due to deep snow. In addition, branches provided for grafting must be collected after defoliation, its available period is limited to mid November before snowfall. This problem also awaken technical difficulty in preserving branches for a long term, at least 4 months till spring. Heating rootstocks in greenhouse can shorten its period but it also spends costs to appoint this method as standard.
To overcome the problems, we studied tissue culture of winter buds available from September. 1/2 WPM medium with IBA and BAP was suitable for multiplicity of bud formation and subcultured every month by cutting on fresh medium and maintained for more than three years. Higher concentration of IBA induced fine roots and succeeded in growing to plantlet.
