MICROPROPAGATION OF JUVENILE AND MATURE AMERICAN BEECH

The purpose of this study was to micropropagate juvenile and mature Am erican beech (Fagus grandifolia Ehrh.) resistant to beech bark disease . Shoot tips (from juvenile seedlings and root sprouts of mature trees ) and buds from branches of mature trees, were cultured and multiplied on aspen culture medium supplemented with 0.89 mu M 6-benzyladenine, 0.27 mu M alpha-naphthaleneacetic acid, 20 g 1(-1) sucrose, and 7 g 1( -1) Difco Bacto-agar. Rooting of shoots was achieved using a 1 minute dip in 12.3 mm indole-3-butyric acid, followed by culture in a Horticu be saturated with half-strength aspen culture medium containing 20 g 1 (-1) sucrose. Thirteen of 33 mature genotypes were established from sh oot tips taken from root sprouts, and six of 41 were established from mature buds. Plantlets of six genotypes were successfully acclimatized to a growth room for three months.