培養基中添加植物生長調節劑對草莓微體繁殖效果的影響

Influences of Plant Growth Regulators in the Medium on Micropropagation of Strawberries (Fragaria ×ananassa)

本試驗以3種草莓品種－－‘桃園一號’、‘三星’（Tristar）及‘粉紅熊貓’（Pink Panda）之芽為培殖體，比較培養基中添加不同植物生長調節劑對生長發育的影響。結果顯示單一芽體增殖倍率最高的處理為全量Murashige and Skoog添加0.5 mg．L^-1 6-benzylaminopurine（BA）。‘桃園一號’、‘粉紅熊貓’及‘三星’分別增殖14.3、18.0及18.5倍。添加Kinetin之效果次之，而添加N6-（γ,γdimethylallyamino）purine（2-ip）的處理增殖倍率最低。品種間對細胞分裂素的種類及濃度之反應表現不同，培殖體形態也各異。培養基中添加BA對自發性長根具有抑制作用。芽培養於不添加生長素的洋菜基礎培養基中，發根率可達100%，發根只需7-8天，添加0.5 mg．L^-1 NAA後延遲到14-24天始見根系長出；但可促進‘桃園一號’及‘粉紅熊貓’培殖體的鮮重及根數。瓶內發根率顯著高於瓶外扦插者，但瓶外根之乾鮮重的比例較瓶內發根者高。 Effects of plant growth regulators in the medium on micropropagation of strawberry (Fragaria ×ananassa Duch.) ‘Taoyuan No.1’, ‘Tristar’ and Fragaria × Potentilla ‘Pink Panda’ were studied. In vitro plantlets were used as explants. The multiplication rates of explants cultured on full strength Murashige and Skoog (MS) medium supplemented with 0.5 mg．L^-1 6-benzylaminopurine (BA) were 14.3,18.5, and 18.0 for ‘Taoyuan No.1’, ‘Tristar’ and ‘Pink Panda’, respectively. The effects of Kinetin and N6-(γ,γ dimethylallyamino) purine (2-ip) on bud multiplication were inferior to the effect of BA. Effects of different types and concentrations of cytokinins on bud multiplication varied among different cultivars, however. Shoots cultured on agar MS medium without adding auxins resulted in 100% rooting after 7-8 days of culture. Addition of 0.5 mg．L^-1 NAA in the medium delayed root initiation, while visible roots appeared after 14-24 days of culture. However, the fresh weight of explants and the number of root in ‘Taoyuan No1’ and ‘Pink Panda’ were significantly increased by an addition of 0.5 mg．L^-1 NAA. In vitro rooting percentage was higher than that en vitro. However, the root dry weight to fresh weight ratio of explants cultured ex vitro was higher than that of explants cultured in vitro.