Low RAPD Polymorphism in Archangiopteris itoi, a Rare and Endemic Fern in Taiwan

台彎的稀有及特有蕨類植物：伊藤氏原始觀音座蓮蕨之低的RAPD多型性

許再文(Tsai-Wen Hsu) ； 牟善傑(Shan-Juei Moore) ； 蔣鎮宇(Tzen-Yuh Chiang)

《Botanical Bulletin of Academia Sinica》 41卷1期 (2000/01) Pp. 15-18

https://doi.org/10.7016/BBAS.200001.0015

摘要

伊藤氏原始觀音座蓮蕨爲台彎的特有蕨類植物，因人爲幹擾處于拯度瀕危，原始顴音座蓮蕨屬的起源依化石證據可追溯到中諸羅紀，野外的顴察指出目前在野外，僅18個植株存活于鳥來的單一族群中。而富時本種發表所根據的模式蓮華池族群則已完全消失；本研究利用RAPD指紋技術偵測個體間的遺傳變异，經40個引子的複製，只有一個引子顯現出個體間的多型性，幷鑑定出6個不同的基因型。族群內低的遺傳變異度可能歸因於過小的族群，而族群大小則受到棲地破壞的影響及限制，在一個小族群內，遺傳漂變有較大的效應使大部分的基因座失去遺傳變異。在本研究中，RAPD資料雖然顯現極低的遺傳變異，但一方面也指出重建族群所需遺傳物質的可得。

關鍵字

伊藤氏原始顴音座蓮蕨 ； 保育生物學 ； 蕨類 ； DNA指紋 ； 遺傳變異 ； 逢機複製多型性DNA片段 ； 台彎

並列摘要

Abstract. Archangiopteris itoi. an endemic fern in Taiwan, is under threat due to human disturbance. Based on fossil evidence the origin of Archangiopteris can be dated to the Middle Jurassic Age. Field survey indicated that only eighteen individuals were left in the wild. The population at Lienhwachi, on which the species was named, is now extinct. The genetic variation of the population remaining at Wulai was assessed by RAPD fingerprinting, Of 40 oligo primers, only one revealed polymorphism. Nevertheless, this primer enabled identification of six haplotypes. The low variability within the population is ascribed to the small population size, which was constrained largely due to habitat disturbance. In the small population, genetic drift will have greater effects leading to loss of variation at most loci. In this study, RAPD data indicated that some variation existed within the population, thus suggesting that materials were available for re-establishment of the populations.

並列關鍵字

Archangiopteris itoi ； Conservation biology ； DNA fingerprinting ； Ferns ； Genetic variation ； RAPD ； Taiwan.