翡翠樹蛙(Rhacophorus prasinatus)族群遺傳結構之探討

Population genetic study of Rhacophorus prasinatus

蔡欣倫(Shin-Lun Tsai)

指導教授 ： 呂光洋 博士

國立臺灣師範大學/理學院/生命科學研究所/碩士(2007年)

摘要

翡翠樹蛙(Rhacophorus prasinatus)，為台灣特有兩棲類，目前僅侷限生活在台灣北部，桃園以北的山區，分別在天然林及耕作環境下都有發現，棲息地多為原始林邊緣或茶園等暫時性積水區，成小族群分布狀態。對於這種遷徙能力低、活動力又不強且對棲息地又有一定的忠誠度，同時分布地區又常有人為環境切割了自然地貌的物種而言，了解其野外族群的遺傳結構是有一定的重要性的。此可以提供適當的資料以利對此物種日後的研究及保育。本實驗將研究台灣特有種翡翠樹蛙的族群遺傳結構，藉由這種侷限分佈在臺灣北部的蛙類進行採集後，與其地形及水域分佈做分析比較，探討其遺傳結構概況，依水系採集了七個樣點，共76隻樣本。結果發現，翡翠樹蛙Fst為0.0891 ~ 0.1461之間，在南北勢溪、大漢溪間雖有中度分化，但彼此間的基因交流仍然很順暢，Nm值皆大於1；h值為0.8295、π值為0.0047，顯示有高的單基因型歧異度與低的核?酸歧異度，亦顯示翡翠樹蛙可能有少數個體組成的祖先成長而來的，且其成長時間已足夠以累積恢復基因型的變異，而各地皆共有一個相同的單基因型，亦有獨自特有的單基因型，但彼此間變異差距不大。利用AMOVA分析發現其變異大多產生在族群內個體間，為89.48%。而翡翠樹蛙族群最大遺傳距離為0.0102，在台灣目前有研究的兩棲類中僅高於諸羅樹蛙。

關鍵字

翡翠樹蛙 ； 族群遺傳

並列摘要

Rhacophorus prasinatus is an endemic species of Taiwan. Currently it is found only in northern mountain region above Taoyuan. It can be found in nature forest and plantation, such as small temporary body in tea plantation. Rhacophorus prasinatus has limited dispersal capabilities due to low mobility and site fidelity. It is important to know the population genetic structure of this species that can provide some useful informations for the future research of conservation. In this study, I invitegated the population genetic structure of Rhacophorus prasinatus, by comparing with landscape and streams. To understand what structure Rhacophorus prasinatus is. 76 individuals from three streams have been analysed. The result of Fst between 0.0891 ~ 0.1461, there are moderate differentiation between Nan-Shih Creek basin、Pei-Shih Creek basin and Tahen basin, but gene flow still can be found, Nm>1. Haplotype diversity=0.8295、nucleotide diversity=0.0047, have high haplotype diversity and low nucleotide diversity. It shows that Rhacophorus prasinatus maybe come from few individuals of ancestors. There is one haplotype shared by all individuals from sample sites, however, individuals of different sample sites have their own unique haplotype, but the difference in genetic variation between haplotype is small. In AMOVA, most genetic variance (89.48%) was explained by differences within population. The maximum intra-specific genetic variance is 0.0102, among amphibian being investigated in Taiwan, Rhacophorus prasinatus is higher than Rhacophorus arvalis only.

並列關鍵字

Rhacophorus prasinatus ； population genetic

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