植物生長調節劑對蝴蝶蘭與朵麗蝶蘭花梗芽增殖之影響

Effect of Plant Growth Regulators on Shoot Multiplication from Flower Stalk Nodal Buds of Phalaenopsis and Doritaenopsis

本文探討蝴蝶蘭屬（Phalaenopsis）與朵麗蝶蘭屬（Doritaenopsis）花梗芽於離體培養時使用植物生長調節劑對腋芽增殖之影響。不同種類與濃度之細胞分裂素對芽體增殖影響顯著。培養基中不含細胞分裂素或濃度過低（1 mg•L^(-1)）時，培植體增殖比率低且有發根之現象；TDZ促使培植體產生不正常之增生並形成不定芽，濃度過高（4 mg•L^(-1)）則新生芽體發育受到抑制。2 mg•L^(-1)BA處理較其他處理組合利於芽體增殖與增大，參試細胞分裂素當中以kinetin誘導腋芽增殖的效果較弱。當細胞分裂素與乙烯抑制劑同時添加時，可提高培植體存活率、鮮重與大芽數，唯高濃度之AVG（100μM）會降低鮮重並抑制芽體增大。添加100μM之AgNO3，較其他處理組合適於腋芽增殖。添加ACC與Ethephon對腋芽增殖顯示抑制之作用。添加乙烯抑制劑於培養基時，培養容器中之乙烯累積量明顯較添加外源乙烯或乙烯前驅物者低。芽體增殖的過程中，瓶內乙烯累積濃度隨培養期間增長而下降，且日週韻律漸趨平緩。 The influence of plant growth regulators on axillary shoot regeneration in in vitro flower stalk nodeculture of Phalaenopsis and Doritaenopsis orchids was studied. The results indicated significant influences ofdifferent kinds and concentrations of cytokinins on shoot regeneration. Low regeneration rate and occasionaladventitious root formation were observed on media without or with low level (1 mg•L^(-1)) of cytokinins. TDZ stimulated nodal explants to proliferate many abnormal adventitious shoots. Higher concentration of TDZ upto 4 mg•L^(-1) inhibited further development of newly induced shoots. BA at 2 mg•L^(-1) level was better thanother cytokinin treatments for shoot regeneration and enlargement growth. Kinetin was less effective thanother cytokinins. Cytokinin combined with ethylene inhibitors in the culture media increased explant survivalrate, fresh weight as well as the number of larger shoots, but high concentration of AVG (100μM) decreasedthe fresh weight and inhibited shoot enlargement. Addition of 100μM AgNO3 was most helpful for axillaryshoot regeneration, but addition of ACC or ethephon was inhibitory. The ethylene content in the culturevessels with ethylene inhibitiors in the media was significantly lower than that with ethylene precursors.During the period of shoot regeneration, ethylene accumulation in the vessels decreased and the diurnalchanges of accumulation diminished along with culture time.