蝴蝶蘭瓶苗棉塞密度對實生苗生長之影響

Density of Cotton Plug Density on the Growth of Phalaenopsis Seedlings

本研究收集4個國內蝴蝶蘭瓶苗生產單位培養瓶之橡膠塞，分析其棉花密度。結果棉花塞密度分佈最低為154mg／立方公分，最高為573mg／立方公分。其中分佈於201-400mg／立方公分者佔72%。另以棉花塞密度為19-573mg／立方公分之培養瓶，培養蝴蝶蘭種苗。器內CO2濃度之日韻律變化及氣孔行為，顯示實生苗於培養3個月後可進行C3型代謝。其根之乾／鮮重比值，隨棉花密度提高而降低；莖葉之乾／鮮重比值，則以76 mg／立方公分棉花密度者最高。在280 mg／立方公分棉花塞密度下培養之植株，葉綠體呈長紡錘形，類囊體膜較429 mg／立方公分棉花塞密度下者排列緊密，澱粉粒及質體小球數目則較少且較小。植株葉背之氣孔密度雖然不因棉花密度而改變，但培養在棉花密度較低的蝴蝶蘭，氣孔在明暗期有開閉度變化。依試驗結果，建議培養蝴蝶蘭瓶苗之棉花塞密度為76 mg／立方公分。 The cotton plug density of rubber stoppers, collected from 4 local phalaenopsis tissue culture nurseries, ranged from 154 to 573 mg/cm^3, and 72% of them were 201-400mg/cm^3. The diurnal change of CO2 concentration and stomata behavior showed that seedlings performed C3 metabolism after 3 months of in vitro culture, regardless of cotton plug density between 19 and 573 mg/cm^3. The root fresh/dry weight ratio decreased as cotton density increased, and plantlets cultured with 76 mg/cm^3cotton plugs showed the highest shoot fresh/dry weight ratio. Plants cultured in flask with 280 mg/cm^3 cotton plug density had long spindleshaped chloroplasts, which had fewer and smaller starch grains and plastoglobulins than that cultured in flask with 429 mg/cm^3 cotton plug density. Stomata density did not change as cotton plug density increased from 280 to 429 mg/cm^3. However, stomata opening/closure was more pronounced in flasks with 280 than with 429 mg/cm^3 cotton plug density. Therefore, the cotton plug density with 76 mg/cm^3 was recommended for phalaenopsis culture.