Induction of multiple buds and needles in tissue cultures of Picea glauca

Hypocotyl segments of white spruce seedlings, when placed with their basal end in a defined medium containing agar and 6-benzylaminopurine (BAP), formed up to 100 or more scale-like organs per segment. The organs did not arise from a preexisting apical meristem. The induction was inhibited by α-naphthaleneacetic acid (NAA). On medium containing 10−5 M BAP and no NAA, 69% of the explants formed multiple organs. When explants bearing the scale-like organs were transferred to media containing neither BAP nor NAA, the organs grew out into needles, and buds developed. Many of the buds developed into elongated shoots.