台灣山茶之分類研究

Taxonomic Study of Camellia formosensis (Masamune et Suzuki) M. H. Su, C. F. Hsieh et C. H. Tsou (Theaceae)

蘇夢淮(Mong-Huai Su)

指導教授 ： 謝長富

共同指導教授 ： 鄒稚華

國立臺灣大學/生命科學院/生態學與演化生物學研究所/博士(2007年)

https://doi.org/10.6342/NTU.2007.02837

摘要

早在1717年，諸羅縣志即出現有關台灣山茶的記載。不過，歷來僅有地方人士利用之。直到1999年茶業改良場成功培育出以台灣山茶為父本的優良紅茶品種，它才開始被受到重視。然而，台灣山茶的分類至今仍然模糊不清，使得它的應用及保育基礎相當薄弱。為使未來相關於台灣山茶的研究以及應用能順利進行，解決最基礎的分類問題是當前首要之工作，此即本論文之目標。本論文總共分為七章。第一章先對台灣山茶的定義、基本特性以及相關的分類史做一介紹，以利後續章節相關問題之探討。

第二章乃針對武威山茶與台灣山茶在分類上的關係做一釐清。因為長久以來缺乏活體與標本可供研究，所以武威山茶一度被認為與台灣山茶乃同一分類群。直到2004年元月武威山茶重新被發現，才得以證明兩者確為不同植物。尤有甚者，武威山茶之形態特徵顯示其應隸屬於烏皮茶屬，因此本人將之重新進行分類處理，稱為武威山烏皮茶。本章的研究成果已經發表在Taiwania (2004, 49: 201-208).

第三章則使用外部形態特徵，以數值分類方法來研究台灣山茶以及其兩個近緣分類群—茶與阿薩姆茶的關係。聚類分析與非線性主成份分析之結果，皆支持台灣山茶為相對獨立的一個分類群。而台灣山茶與另兩者最大之不同，在於台灣山茶之新芽為光滑或僅具稀疏之毛，而另兩者皆密被毛；此外台灣山茶的子房光滑，而另兩者則密被毛。其它如嫩枝、葉柄以及葉下表面之毛被狀況，亦可做為分群之輔助。在營養特徵的分析中，台灣山茶的台東族群，呈現與西部的族群較大之差異，暗示分布於台東者為比較特殊之一群。本章的研究成果已經被Taiwania接受。

第四章則是探討台灣山茶、茶與阿薩姆茶在花粉形態上的差異。結果發現，台灣山茶在花粉外壁內層的雕紋與花粉極面的形狀上，與另兩者有所不同，此點再度說明台灣山茶的確為不同於茶與阿薩姆茶的植物。至於不同地區的台灣山茶之間、或是茶與阿薩姆茶之間，皆無法以花粉形態來區分。

第五章乃針對台灣山茶、茶以及阿薩姆茶在氣孔形態及葉片橫切面的解剖構造進行比較。在氣孔形態方面，氣孔周圍角質層突起與異型氣孔的具備與否，可以將所有的樣本分成兩群。在台灣山茶中，除南投的族群之外，皆屬不具有窄肋狀角質層突起與異型氣孔之類群，然而南投族群卻和茶以及阿薩姆茶一樣，皆具有窄肋狀角質層突起與異型氣孔。因此，氣孔形態支持南投族群與其它族群間存在著差異。至於葉片解剖部分，則無顯著的特徵差異可供分群之用。但是根據初步之定性觀察，台灣山茶之葉部內含石細胞密度甚高，此點或可能在未來以統計方法取樣及分析，為台灣山茶之分類提供更多之證據。

第六章嚐試以DNA定序法，來探討台灣山茶與兩近緣分類群的關係。以最大簡約法及鄰近連接法對RPB2 intron 11-16與intron 23兩段序列進行親緣分析，並計算類群間的平均遺傳距離，用以比較各類群在DNA上的差距。結果支持台灣山茶為單源群，且與茶和阿薩姆茶關係較為疏遠。在台灣山茶之中，採自南投與台東的樣本較為接近，而嘉義至屏東的樣本則獨立成另一群。此外，台灣山茶與茶或是阿薩姆茶間的遺傳距離，皆明顯大於茶與阿薩姆茶間的遺傳距離。

第七章則根據前面的研究結果，對台灣山茶進行分類處理。由於台灣山茶相對於茶或是阿薩姆茶皆有較大之差異，基於分類學家對茶與阿薩姆茶所進行的分類處理，本人將台灣山茶處理成種之階級，學名稱為Camellia formosensis (Masamune et Suzuki) M. H. Su, C. F. Hsieh et C. H. Tsou。同時，因為台灣山茶之台東族群在外部形態上已有明顯分化，所以將之處理成變種並命名為C. formosensis var. yungkangensis M. H. Su, C. F. Hsieh et C. H. Tsou，中名稱之為永康山茶。

關鍵字

台灣山茶 ； 永康山茶 ； 分類學 ； 數值分類

並列摘要

The Taiwan native wild tea plant was first documented in 1717 on Chu-lo-hsien-chih. The utilization of this plant is mostly restricted to local people until 1999, when a black tea clone was bred by the Tea Research and Extension Station. The researches, applications and conservations on the Taiwan native wild tea plant were limited due to several uncertainty about its taxonomy. This dissertation is set out to elucidate the taxonomic status of the Taiwan native wild tea plant based on morphological and molecular evidences.

There are seven chapters in the dissertation. In chapter 1, the definition, background and taxonomic history of the Taiwan native wild tea plant were introduced.

Chapter 2 concerns about the Camellia buisanensis and the Taiwan native wild tea plant. Because of a lack of materials for examination, some taxonomists thought C. buisanensis is the same with the Taiwan native wild tea plant until living plants were rediscovered in January 2004. Differences between the two taxa become apparent. Morphological data indicate that C. buisanensis is indeed a member of the genus Pyrenaria. Therefore, C. buisanensis was treated as Pyrenaria buisanensis, the results were published in Taiwania (2004, 49: 201-208).

In Chapter 3, the relationship between the Taiwan native wild tea plant and its two closely related taxa - C. sinensis var. sinensis and C. sinensis var. assamica - was explored by numerical methods using morphological characters. Results of the cluster analysis and nonlinear principal component analysis supported the Taiwan native wild tea plant as a distinct taxon. Buds of the Taiwan native wild tea plant are glabrous or sparsely hairy, while those of C. sinensis var. sinensis and C. sinensis var. assamica are densely hairy. Ovaries of the Taiwan native wild tea plant are glabrous, while those of C. sinensis var. sinensis and C. sinensis var. assamica are densely hairy. Vegetative characteristics of the Taiwan native wild tea plant from Taitung are different from individuals in other area, suggesting differentiation or specialization in the Taitung population. The results had been accepted by Taiwania.

In Chapter 4, the morphology of pollens from the Taiwan native wild tea plant, C. sinensis var. sinensis and C. sinensis var. assamica were compared. The pollens of Taiwan native wild tea plant were different from the other two closely related taxa in the sculpture of nexine and the shape at the polar side. In contrast, C. sinensis var. sinensis and C. sinensis var. assamica couldn't be distinguished by the morphology of pollens.

In Chapter 5, the stomatal and leaf anatomy of the Taiwan native wild tea plant, C. sinensis var. sinensis and C. sinensis var. assamica were compared. As to the stomatal morphology, the Taiwan native wild tea plant except for the Nantou population didn't have the ribbed cuticles and heteromorphic stomata, while Nantou population, C. sinensis var. sinensis and C. sinensis var. assamica did. Therefore, stomatal morphology supported Nantou population is special. There was no markly difference in leaf anatomy. The density of stone cells in leaves of the Taiwan native wild tea plant seems to be higher than the other two taxa. However, future studies to quantify this character might provide further evidence on taxonomic properties.

In Chapter 6, phylogenetic analyses were conducted using sequences of two DNA fragments, RPB2 intron 11-16 and intron 23. Results by the maximum parsimony and neighbor joining supported the Taiwan native wild tea plant is monophyletic. The genetic distance between the Taiwan native wild tea plant and C. sinensis var. sinensis, or C. sinensis var. assamica, was larger than that between C. sinensis var. sinensis and C. sinensis var. assamica. Within the Taiwan native wild tea plant, Nantou and Taitung populations were similar than Chiayi-Pingtung population.

In Chapter 7, taxonomic treatment on the Taiwan native wild tea plant was proposed, according to results of the previous chapters. Because the Taiwan native wild tea plant is distinct from C. sinensis var. sinensis and C. sinensis var. assamica, a specific rank for the Taiwan native wild tea plant was proposed. The name was given as Camellia formosensis (Masamune et Suzuki) M. H. Su, C. F. Hsieh, et C. H. Tsou. Meanwhile, the Taitung population was named as C. formosensis var. yungkangensis M. H. Su, C. F. Hsieh, et C. H. Tsou, for its markedly differences in the vegetative morphology.

並列關鍵字

formosensis ； yungkangensis ； taxonomy ； numerical taxonomy

參考文獻

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Keng, H. 1973. Nomenclatural note on Wu Pi Cha or the black-barked tea plant. Taiwania 18: 55-56.

Lai, J.-A., W.-C. Yang, and J.-Y. Hsiao. 2001. An assessment of genetic relationships in cultivated tea clones and native wild tea in Taiwan using RAPD and ISSR markers. Bot. Bull. Acad. Sin. 42: 93-100.

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