臺灣嚴重瀕絕植物－－紫芋蘭之無菌播種與植株再生

Asymbiotic Germination and Plant Regeneration of ＂Eulophia dentate＂ Ames, a Critically Endangered Plant in Taiwan

依據臺灣維管束植物紅皮書初評名錄對4,174種適用評估物種中，紫芋蘭（Eulophia dentate Ames）為嚴重瀕臨絕滅（Critically Endangered, CR）植物，其近80年來僅見於兩個分布地，個體數量僅50~250株，因分布狹窄且生育地易受干擾破壞，急待進行保育之研究。本研究以修正無菌播種MS培養基巨量元素減半為1/2或1/4，並於培養基中添加香蕉泥（banana homogenate, BH）、椰子水（coconut water, CW）、馬鈴薯（Potato, PO）及蛋白腖（peptone, PET）等有機添加物，結果顯示暗培養35~40天以1/2 MS+ PET、1/4 MS+ PET 及1/4 MS+ CW培養基中，擬原球體（Protocorm Like Bodies, PLBs）形成數分別301.17 ± 75.47、297.33 ± 73.43和286.00 ± 41.79為最多，較其他培養基有顯著性差異。而PLBs芽體增殖試驗經培養4個月，平均1個PLB可誘導8.27 ± 3.68個芽體，且可繼續發育成型態正常之小植株。本研究成功建立臺灣嚴重瀕絕植物紫芋蘭無菌播種與小植株再生，可作為臺灣嚴重瀕絕植物繁殖、種原保存及後續復育再引回之基礎研究。

According to the A Preliminary Red List of Taiwanese Vascular Plants, ＂Eulophia dentate＂ belongs to the category of Critically Endangered (CR). Nearly 80 years ago only two habitats have been found. The number of individuals are only about 50-250 strains. The specie's narrow distribution and vulnerability to disturbance make it an urgent case for conservation researches. In this study, we successfully established a protocol for asymbiotic germination and plant regeneration of ＂Eulophia dentate＂ Ames, a critically endangered plant in Taiwan. Seeds of this species were collected in a native habitat, and their surface were disinfected before growing ＂in vitro＂ on 1/2 MS and 1/4 MS medium. Organic growth supplements such as banana homogenate, coconut water, potato, and peptone were added. After 35 to 40 days of dark culture, embryos grew to protocorm, followed by plantlet formation. Results show that the medium 1/2 MS+PET, 1/4 MS+PET, and 1/4 MS+CW were the best for PLBs formation. The shoots proliferated from PLBs and were maintained by subculturing on the 1/2 MS medium. On average, 8.27±3.68 shoots could be obtained from a PLB after being transferred to the 1/2 MS medium. Shoot buds elongation and root formation occurred after four months of culture. This study could be used as a reference for endangered plants propagation, germplasm preservation, and restoration in Taiwan.