In vitro regeneration of Alnus cremastogyne Burk from epicotyl explants

Multiple shoots were grown from seedling explants of Alnus cremastogyne Burk by a two-stage culture procedure: initiation on WP medium supplemented with 2-8 μ M benzylammopurine(BAP) for 6 weeks, thereafter 3 weeks of subculture(shoot multiplication) on the same medium with 1 μ M BAP. A 5-9 fold multiplication rate was achieved. Type and concentration of sugar used in the multiplication medium were shown to be critical factors for both multiple shoot induction and bud elongation, the optima being 87.5mM glucose and 87.5mM sucrose respectively. After transfer to half-strength WP media either containing indolebutyric acid (IBA) or lacking plant growth regulator, almost all the shoots rooted. However, high rhizogenesis could be achieved only with shoots cultured in rooting medium containing 87.5mM sucrose or 175mM glucose, and shoots from multiplication media containing 87.5mM sucrose. Survival of the plantlets following transfer to vermiculite was 100%.