Plant Regeneration and Mass Propagation of Betula tatewakiana by Winter Bud Culture

ヤチカンバの冬芽をBAP0.8mg/lを添加したWPM上で培養することによりシュートを伸長させ，さらにそのシュートを切り取って，IBA0.5mg/lとNAAを0.02mg/l添加した1/2MS培地にさしつけることで，発根させ幼植物体を再生させることができた。また，再生した幼植物体の茎軸，葉柄および腋芽を，BAP0.8mg/lとGA3 5.0mg/lを組み合わせて添加したWPMで培養したところ，BAPを添加した培地で，腋芽からマルチプルシュートを誘導することができ，種苗の大量増殖が可能であることが明らかになった。また，GA3の添加は，BAPと併用した場合にシュート数の増加に有効であった。Winter buds of Betula tatewakiana were cultured on WPM containing 0.8mg/l of BAP. Shoots were successfully elongated from the buds on the medium. The shoots were cut and inoculated on to 1/2MS containing 0.5mg/l of IBA and 0.02mg/l of NAA. They were successfully rooted on the medium and regenerated perfect plantlets. Internodal segments, petioles and axillary buds were isolated from the plantlet and cultured on a medium containing 0.8mg/l of BAP and 5.0mg/l of GA3. Multiple shoots were elongated from the axillary buds cultured on a medium containing 0.8mg/l of BAP. GA3 concentration in the medium was effective in the proliferation of shoots when it was added with BAP