거제수나무 秀型木의 組織培養 클론 增殖에 미치는 培養條件의 影響

Effect of cultural conditions on clonal propagation of betula costata plus trees by tissue culture

In vitro clonal propagation methods have been established using selected plus trees of Betula costata through axillary bud culture. The primary explants were collected from 5-year-old grafts of eight plus tree clones. The explants were cultured on Woody Plant Medium(WPM) supplemented with 0.5㎎/ℓ kinetin after surface sterilization. Average 42.1% of explants of all clones tested developed shoots. Nodal segments and shoot tips originated from microshoots were subcultured on four different media for shoot proliferation. The optimum media for shoot proliferation varied with subcultured explants. While WPM supplemented with 0.1㎎/ℓ BAP and 0.05 ㎎/ℓ IBA was shown to be best for nodal segment, Driver Kuniyuki Walnut(DKW) medium supplemented with 0.1 ㎎/ℓ BAP and 0.05 ㎎/ℓ IBA was better for shoot tip. The shoot proliferation could be achieved by subculturing on WPM and DKW media supplemented with 1.0 ㎎/ℓ BAP and 0.05 ㎎/ℓ IBA at four-weeks intervals. Although all clones tested could be propagated, microshoot growth and shoot proliferation rate varied with the clones. Plantlets were produced from ex vitro rooting(over than 90%) and acclimatized successfully in the field.