台灣產薯蕷屬植物親緣關係之研究

Phylogenetic Relationship of the Genus Dioscorea L. (Dioscoreaceae) of Taiwan

多種薯蕷屬植物爲經濟作物。爲探討台灣產薯蕷屬植物之親緣關係，本研究以matK與rbcL二段葉綠體基因片段作爲遺傳標誌，自台灣本島及離島採集16種薯蕷屬植物，並從GenBank下載8種薯蕷屬植物序列進行比對，使用PAUP軟體進行neighbor joining、maximum parsimony及maximum likelihood親緣關係分析，並與Bayesian樹狀圖整合呈現。結果顯示台灣產薯蕷屬植物主要分爲二大分支，一爲根狀莖節（section Stenophora）；另一分支包含丁字形毛節（section Combilium）、基生翅節（section Opsophyton）、複葉節（section Botryosicyos）、白薯榔節（section Lasiophyton）及周生翅節（section Enantiophyllum）5節，這5節之親緣關係在此分支中亦可明確區分開來。本研究之分子數據演算結果與形態分類相吻合，支持台灣產薯蕷屬植物，在屬階層之下分屬6節的分類架構。

Several species of the genus Dioscorea (Dioscoreaceae) are commercially important cultivated plants. We used DNA sequences of the chloroplast genes rbcL and matK to conduct phylogenetic analysis of 16 species of Dioscorea from Taiwan with 8 species of China, Thailand and Madagascar retrieved from GenBank as the referent species. The phylogenetic trees were constructed with the neighbor joining, maximum parsimony, maximum likelihood, and Bayesian methods. The phylogenetic tree reconstructed revealed that Taiwan's Dioscorea were divided into two clades; clade A is the section Stenophora and clade B is composited of the sections Combilium, Opsophyton, Botryosicyos, Lasiophyton and Enantiophyllum. The phylogenetetic relationship of the Dioscorea in Taiwan based on the cpDNA sequences agreed with that derived from the morphological characters. The datasets also supported the infrageneric structure.