臺灣產黃斑龍膽及鴛鴦湖龍膽之親緣地理及族群遺傳結構探討

Phylogeography and genetic structure of Gentiana flavomaculata and G. flavomaculata var. yuanyanghuensis in Taiwan

黃珮瑩(Pei-ying Huang)

指導教授 ： 張永達

國立臺灣師範大學/理學院/生命科學研究所/碩士(2009年)

摘要

龍膽屬（Gentiana L.）植物，屬於龍膽科（Gentianaceae），龍膽族（Gentianaeae）。台灣本地產龍膽屬植物可分為多年生草本及一年生草本兩類，本論文研究材料黃斑龍膽（Gentiana flavomaculata）及鴛鴦湖龍膽（G. flavomaculata var. yuanyanghuensis）均為台灣特有種之一年生草本。黃斑龍膽及鴛鴦湖龍膽在形態上及地理分布上略有區隔，但兩類群又呈現極高的相似度，因此本研究擬以葉綠體 rps4基因探討台灣產黃斑龍膽及鴛鴦湖龍膽是否在分子分類上，可藉由分子遺傳證據將之有效區分，同時亦結合微衛星DNA序列探討其族群分化情形，分析其遺傳多樣性特徵。結果顯示，黃斑龍膽與鴛鴦湖龍膽之間的核苷酸歧異度僅有0.2%，在多樣性分析方面，於兩種龍膽的所有葉綠體片段中，共只得到8個單套型核酸（haplotype, h），且以聚類樹形分析法（neighbor-joining tree, NJ tree）利用kimura雙參數模式進行黃斑龍膽與鴛鴦湖龍膽族群的親緣演化樹建構，結果顯現兩者呈現出具有共用單型的現象。再根據AMOVA分析，葉綠體DNA與微衛星DNA的結果呈現一致結果，在種間鴛鴦湖龍膽與黃斑龍膽之間的遺傳分化指數相當非常低（ΦCT = 0.064, cpDNA; ΦCT =0.057, microsatellite DNA），顯示兩者並沒有遺傳上顯著的分化情形結合以上特徵，表示黃斑龍膽以及鴛鴦湖龍膽的族群間尚保有基因交流的機制，在分子分類上，尚無法支持成為有效的獨立種，因此本研究建議黃斑龍膽與鴛鴦湖龍膽在分子層級上，應暫處理為種下階級較為合適。

關鍵字

黃斑龍膽 ； 鴛鴦湖龍膽 ； rps4 ； 分子分類 ； 微衛星DNA

並列摘要

Gentiana L. is belonged to Gentianaceae, Gentianaeae. The Gentiana in Taiwan includes perennial and annual herbaceous species. Both Gentiana flavomaculata and G. flavomaculata var. yuanyanghuensis are annual and endemic in Taiwan. Though there are some distributional and morphological differences between these two species, however, highly similarity still exists among taxons. In order to test whether G. flavomaculata and G. flavomaculata var. yuanyanghuensis were genetically differentiated and genetic diversity characteristics, chloroplast rps4 was combined with microsatellite DNA to discuss phylogenetic structure and genetic differentiation. The result showed only 0.2 % nucleotide diversity between G. flavomaculata and G. flavomaculata var. yuanyanghuensis and eight haplotypes were found among all chloroplast segments, which were highly shared by two species according to Neighbor - Joining K2P tree. The AMOVA showed congruent result of chloroplast and microsatellite and low genetic differentiation among species (ΦCT = 0.064, cpDNA; ΦCT =0.057, microsatellite DNA ), implying genetic exchange mechanism among populations of these two specie, and these two species could not be spported as different species phylogenetically. As a result, we suggested G. flavomaculata and G. flavomaculata var. yuanyanghuensis should temporarily be treated as a infra-species based on phylogenetic evidence.

並列關鍵字

G. flavomaculata ； G. flavomaculata var. yuanyanghuensis ； rps4 ； phylogenetic taxonomy ； microsatellite DNA

參考文獻

Liu, T.S., & C.C. Kuo. 1970. Studies on the Taiwan species of Gentianoideae. Ann. Taiwan Mus. 13: 98-130.

Masamune, G. 1943. Miscellaneous notes on the flora of Eastern Asia ⅩⅩⅤ. Trans. Nat. Hist. Soc. Form. 33: 108-111.

Ying, S.S. 1989. Systematic study on Gentianaceae of Taiwan. Quarterly Journal of the Experimental Forest of National Taiwan University. 3(2): 87-111.

陳志雄（2001）。龍膽屬內小龍膽組的親緣關係研究。國立台灣師範大學生命科學研究所博士論文。

黃啟俊（2006）。台灣產玉山杜鵑複合群之親緣地理學研究。國立成功大學生命科學研究所碩士論文。