黛粉葉高效率體胚增殖與胚苗轉化

High Efficient Somatic Embryo Multiplication and Embling Conversion of ＂Dieffenbachia＂ 'Tiki'

In this study, a regeneration system was developed for improving the efficiency of somatic embryogenesis and embling recovery by using male inflorescences and mature somatic embryos of ＂Dieffenbachia＂ Schott 'Tiki'. The highest percentage (100%) of primary somatic embryogenesis (PSE) and the highest yield (75.2) of mature primary embryoids were obtained using a half strength modified Murashige and Skoog (MS) medium containing 2 mg•L^(-1) dicamba and 0.5 mg•L^(-1) thidiazuron (TDZ) from male inflorescence explants. The mature embryoids obtained from PSE were also used to induce secondary or repetitive somatic embryogenesis. PSEs derived from male inflorescence were cross-cut into four sections before subculturing them on the same basal medium supplemented with 2 mg•L^(-1) dicamba and 0.5-1.0 mg•L^(-1) TDZ. The highest secondary somatic embryogenesis frequency (100%) was obtained after 8 weeks of culture, and the highest yield of mature secondary embryos, 33.0-34.3 per explant, was obtained after 13 weeks of culture. In addition, embling conversion of mature secondary embryos was investigated. Green secondary embryos, 4-5 mm in size and 8-10 weeks in age, were cultured on a half strength modified MS medium supplemented with 150 mL•L^(-1) coconut water as a basal medium for embling conversion. The results indicated that the highest converted frequency was 73.3%, and the number of converted emblings per explant reached 7.8 when the medium contained 0.5% glucose and 1.0 mg•L^(-1) TDZ. Plantlets regenerated from the germinated embryoids acclimatized in the greenhouse and exhibited vigorous growth. 本研究探討黛粉葉體胚發生量化增殖效率與胚苗轉化再生體系。雄花序培植體於半量MS基本鹽類，添加20 g•L^(-1)蔗糖、10 g•L^(-1)葡萄糖及1.8 g•L^(-1)水晶洋菜等為基礎培養基，結果顯示在2 mg•L^(-1)dicamba及0.5 mg•L^(-1)TDZ組合，具有最高之初級體胚發生頻率可達100%以及最多成熟體胚形成數達75.2個，對黛粉葉雄花序培植體高效率體胚發生的促進，具顯著的效果。以得自前一試驗均質之初級體胚，作為次級培植體來源，繼代培養於相同基本培養基添加2 mg•L^(-1)dicamba及TDZ（0.5、1.0 mg•L^(-1)），培養13週後顯現最高效率的次級體胚發生頻率（100%），次級體胚形成數則高達34.3及33.0個，顯示此培養基組成可有效促進次級體胚發生和體胚量化增殖。此外，成熟次級體胚在1/2 MS添加150 mL•L^(-1)椰子水之培養基組成之胚苗轉化顯示，大小約為4-5 mm次級體胚，培養在含有0.5%葡萄糖及1.0 mg•L^(-1)TDZ濃度培養基中其胚苗轉化率最高達73.3%；平均每一培植體之胚苗轉化再生植株最多達7.8個，且可發育成為具形態雙極性之獨立個體。胚苗轉化之再生植株經出瓶種植在溫室中具有良好的生長活力。