曲足蘭根尖類原球體之誘導與再生

Induction and Regeneration of Protocorm-like Bodies from Root Tips of Cyrtopodium paranaense (Orchidaceae)

郭瑋玲(Wei-Ling Guo) ； 林玉富(Yu-Fu Lin) ； 楊采凌(Tsai-Ling Yang) ； 林雅莉(Ya-Li Lin) ； 張耀乾(Alex Yao-Chien Chang) ； 高建元(Chien-Yuan Kao)

《宜蘭大學生物資源學刊》 6卷1期 (2010/12) Pp. 27-33

https://doi.org/10.6175/job.2010.61.14

摘要

曲足蘭為一種熱帶地生蘭，主要是經由有性種子繁殖子代。在本研究中，我們證實曲足蘭根尖形成的植株再生現象是經由根類原球體轉變的一種無性形態發生。曲足蘭的組培苗培養在不添加植物生長調節劑（plant growth regulators PGRs）的MS培養基中，會零星地從其根部尖端長出類原球體。這些外觀緊實的根尖類原球體最終會發育成熟成為形態正常的幼苗。經由組織學的切片觀察顯示，在根尖類原球體形成的早期階段，根帽組織會漸漸地從根部的頂端分離，根部原有的維管束組織再延伸進入根尖膨大的球體構造，最後形成一個完整成熟的類原球體再發育生長成為植株。類原球體也會從根部的中柱組織發生。將分離的根尖培植體進行培養，在不添加植物生長調節劑的培養基中並不會形成類原球體，但將此分離的根尖培植體培養於添加10.2μM吲哚乙酸（IAA）及9.0μM噻苯脲（TDZ）的MS培養基中則會誘導出根尖類原球體。IAA及TDZ都可以促進離體根尖產生根尖類原球體，然而TDZ在沒有IAA存在的情況下，無法單獨誘導根尖類原球體的形成，這個結果說明此兩種植物生長調節劑對於根尖類原球體的形成具有協同作用。成熟的根尖類原球體可以在不含有植物生長調節劑的培養基中進行大量增殖並再生成完整植株。根尖培養也許可以被用來作為曲足蘭無性增殖的方式之一。

關鍵字

根尖培養 ； 體胚 ； 無菌繁殖 ； 類原球體 ； 吲哚乙酸 ； 噻苯脲

並列摘要

Cyrtopodium paranaense is a tropical terrestrial orchid, which propagates mainly through sexual seed germination. In this study, we document the asexual morphogenesis of the root tip to protocorm-like body (PLB) conversion in Cyrtopodium paranaense. Protocorm-like bodies sporadically developed from root tips of flask-grown seedlings in the absence of any exogenous plant growth regulators (PGRs). The compact PLBs ultimately gave rise to normal plantlets. Histological observations revealed that the root cap became dissociated from the root apex at an early stage followed by dispersed extension of root vascular strands into nascent PLBs. Protocorm-like bodies also developed from the root central stele tissue. In root tip segment cultures, PLBs were not formed without providing PGRs but were efficiently formed from root tips in Murashige and Skoog (MS) medium supplemented with 10.2 μM indole-3-acetic acid (IAA) and 9.0 μM thidiazuron (TDZ). Both IAA and TDZ promoted the formation of PLBs; however, TDZ did not induce PLB formation in the absence of IAA, indicating a synergistic effect of the two PGRs. Protocorm-like bodies were proliferated and subsequently plants regenerated in PGR-free MS medium. Root tip culture may be used as an alternative method for the propagation of Cyrtopodium paranaense.

並列關鍵字

root tip culture ； somatic embryogenesis ； in vitro propagation ； protocorm-like body ； indole-3-acetic acid ； thidiazuron