王俊能Wang, Chun-Neng臺灣大學:生態學與演化生物學研究所周延威Chou, Yen-WeiYen-WeiChou2010-05-112018-07-062010-05-112018-07-062009U0001-1801200919161100http://ntur.lib.ntu.edu.tw//handle/246246/183023臺灣杉屬（Taiwania）與著名的加州紅木和水杉相同，屬於第三紀孓遺裸子植物。化石與花粉的紀錄顯示臺灣杉屬的族群在第三紀時曾廣泛分布於歐亞大陸的溫帶地區，範圍甚至到達北美，然而現存的臺灣杉屬族群範圍僅零星分布於臺灣、中國華南、緬甸北部與越南北部。由於臺灣杉屬的現存族群在亞洲呈現間斷分布模式，這些零星分布的族群可能暗示著亞洲植物在第三紀時期向南遷徙、在第四紀冰河期時植物遷徙來臺灣、以及亞洲冰河期避難所生成的過程資訊。然而，即使過去的研究曾經分析過這些零星族群間的形態與遺傳變異，至今對於亞洲現生的臺灣杉屬族群仍然缺乏大規模的親緣地理研究。本研究使用五個cpDNA序列片段（petG-trnP、trnH-psbA、trnV-trnM、trnC-ycf6與trnL-trnF）分析臺灣與中國、以及最近在越南新發現的臺灣杉屬族群間的遺傳變異，結果只找到八種cpDNA單套型，顯示亞洲現存的臺灣杉屬族群的cpDNA遺傳多樣性極低。在所有臺灣的族群中只發現一種cpDNA單套型，且此單套型並不存在於東南亞洲大陸（中國與越南）的臺灣杉屬族群之中。單套型網狀圖的結構顯示臺灣族群的單套型A與東南亞洲大陸的單套型B間存在八個突變步驟的差異，表示臺灣與東南亞洲大陸間的臺灣杉屬族群存在著極大的分化。相對而言，成對族群間的FST、Nm與AMOVA分析結果則顯示中國與越南的族群間在cpDNA的遺傳上較為接近。分歧時間的估算結果顯示臺灣與東南亞洲大陸的臺灣杉屬族群分化時間平均為1.9-2.5 mya，位於上新世（Pliocene）的晚期。本研究的結果顯示臺灣與東南亞洲大陸的臺灣杉屬族群間存在著極大分化，兩地族群各自保留的單套型可能在臺灣杉屬族群遷徙至臺灣之前，便已經發生分歧演化。現今臺灣杉屬族群cpDNA單套型的分布模式甚至暗示臺灣與東南亞洲大陸現生臺灣杉屬單套型可能各自擁有不同的起源。東南亞洲大陸現生臺灣杉屬族群所呈現的零星分布與cpDNA的遺傳變異情形則可能是南方的殘餘族群在冰河期結束後發生破碎化，並退縮至數個避難所的結果。Taiwania is one of the Tertiary relic gymnosperms like the well-known Sequoia and Metasequoia. Fossil and pollen record evidence indicated that it was once widespread in the temperate region of Eurasia and even in North America but now only disperses in Taiwan, Southern China, northern Myanmar and northern Vietnam. Because the living populations of Taiwania have a scattered distribution pattern in Asia, these scattered populations may indicate information about the southward dispersal of Asian plants in the Tertiary, the dispersal of plants to Taiwan during the Quaternary glacial periods, and the formation of glacial refugia in Asia. However, although previous studies had analyzed the morphological and genetic variation among Taiwania populations scattered in Asia, no extensive phylogeographic study has ever been conducted to these surviving populations until now. In this study, five cpDNA regions (petG-trnP, trnH-psbA, trnV-trnM, trnC-ycf6 and trnL-trnF) were sequenced to analyze the genetic variation among Taiwania populations in Taiwan, China and a recently discovered population in Vietnam. Only eight haplotypes were distinguished, implying low genetic variations in all extant Taiwania populations. All Taiwanese populations consist only one haplotype, which is absent in the SE Asiatic mainland (Chinese and Vietnamese) populations. The haplotype network also revealed an eight-mutational-step difference between the Taiwanese haplotype A and the Asiatic mainland haplotype B, suggesting a strong genetic differentiation between Taiwania populations in Taiwan and in the SE Asiatic mainland. In contrast, the results of pairwise FST, Nm, and AMOVA implied a closer relationship between the Chinese and Vietnamese populations. The results of divergent time estimation suggest that the average differentiation time between the populations in Taiwan and the SE Asiatic mainland was ca. 1.9-2.5 mya, which was during the late Pliocene. Results in this study suggest a large differentiation between the remnants of Taiwania in Taiwan and in the SE Asiatic mainland, in which the two distinct haplotype lineages preserved in Taiwan and in the SE Asiatic mainland were probably diverged before the dispersal of ancient Taiwania populations to Taiwan. The distribution pattern of cpDNA haplotypes in living Taiwania populations may even suggest that the two haplotype lineages found in Taiwan and in the SE Asiatic mainland have two distinct origins. The scattered distribution pattern and the cpDNA variation of living Taiwania populations in Asia may be the result of fragmentation and retreat into several refugia, which was happened after the end of Quaternary glacial cycles.誌謝……………………………………………………………………………… i文摘要………………………………………………………………………… ii文摘要…………………………………………………………………………. iv錄……………………………………………………………………………….　vi、緒論………………………………………………………………….. 1一、第三紀孓遺裸子植物（Tertiary relic gymnosperms）與冰河期避難所（glacial refugia）：植物族群對古代地質與氣候變遷的見證..................................　1二、冰河期避難所在亞洲與臺灣的形成背景...................................................　2三、臺灣杉屬（Taiwania）：殘存於臺灣、中國與越南的第三紀孓遺裸子植物...................................................................................................................　4四、親緣地理學的概念與研究方法...................................................................　7五、研究目標.......................................................................................................　14、材料與方法……………………………………………………………… 15一、樣本採集……………………………………………………………………　15二、實驗方法……………………………………………………………………　15三、資料分析……………………………………………………………………　17、結果……………………………………………………………… 22一、臺灣杉屬族群的遺傳多樣性與分化...........................................................　22二、譜系分析與巢狀支序親緣地理分析...........................................................　23三、分歧時間估算...............................................................................................　24、討論……………………………………………………………… 26一、臺灣杉屬族群的遺傳多樣性與分化...............................................................　26二、亞洲臺灣杉屬族群間的譜系、分歧時間與親緣地理關係...........................　29三、亞洲大陸現存臺灣杉屬族群的演化歷史......................................................　31四、現生臺灣杉屬族群起源之可能性..................................................................　33五、總結與展望......................................................................................................　34考文獻…………………………………………………………………….…… 37表………………………………………………………………………………. 49圖………………………………………………………………………………. 58application/pdf2140920 bytesapplication/pdfen-US臺灣杉屬第三紀孓遺裸子植物冰河期避難所cpDNA分歧時間TaiwaniaTertiary relic gymnospermsglacial refugiadivergent timehttp://ntur.lib.ntu.edu.tw/bitstream/246246/183023/1/ntu-98-R95B44001-1.pdf