生長素對黛粉葉雄花序培養體胚發生之影響

Effect of Auxin Concentration on Somatic Embryogenesis from Male Inflorescence Culture of Dieffenbachia 'Tiki'

本研究主要探討生長調節在黛粉葉雄花序培植體體胚發生之影響，MS培養基含46 mg／L 2, 4-D對於胚性癒傷組織生長最佳，可在12週培養週期長滿整個花序軸表面，並且有利於硬而脆的乳白色胚性癒傷組織形成。雄花序在修改之1／2MS培養基含2%蔗糖、1%葡萄糖與0.18%水晶洋菜的固體培養基，添加不同2,4D／kinetin濃度比值對黛粉葉體胚發生之影響，結果在2,4D／kinetin ratio為2.0／0.5、3.0／0.5、4.0／0.5、5.1／0.5等觀察到胚狀體的形成，胚狀體發生率最高為26.7%；根據胚狀體形成百分率分析黛粉葉體胚發生潛能，顯示2,4D濃度的增加，與黛粉葉體胚發生頻率呈現顯著相關（r^2=0.94）。再依前項結果修改生長素為2,4D、dicamba及picloram等高活性的生長素參試，結果指出高活性的dicamba、picloram在濃度為2mg／L培養基，培養第8週能夠獲得高活性的胚性癒傷組織發生，其中2mg／L Dicamba達到指數IV的胚性癒傷組織指數為72.1%為最高，在12週培養可見30%的成熟體胚形成，平均每個雄花序培植體可得22.2體胚，顯著高於其它處理別。 A method for the somatic embryogenesis of Dieffenbachia 'Tiki' hybrids was described. Male inflorescence explants isolated from spadix of flowering plants cultured in vitro, formed embryogenic calli on surfaces of inflorescence axis within eight weeks of culture on full-strength Murashige and Skoog (MS) medium with 4-6mg/L 2, 4-D.Somatic embryogenesis and embryoid were induced using a modified-half-strength MS combination of 2% sucrose with 1% glucose, 0.18% Gelrite for the basal medium, supplemented with 2.0 to 5.1 mg/L 2,4dichlorophenoxyaceticacid (2, 4-D) and 0.5mg/L Kinetin. Male inflorescence explants transfer to modified half-strength MS basal medium with 0.5mg/L Kinetin and 4mg/L2, 4D (or 24mg/L Dicamba) resulted in somatic embryogenesis at frequencies were 4572.1% with an average of 13.322.2 somatic embryos per responding explant. In this study, we are the first to report somatic embryogenesis in Dieffenbachia 'Tiki'.