傅氏鳳尾蕨複合群生物學之研究

Biological studies of Pteris fauriei complex (Pteridaceae)

黃曜謀(Yao-Moan Huang)

指導教授 ： 王震哲 ； 周雪美

國立臺灣師範大學/理學院/生命科學研究所/博士(2006年)

摘要

傅氏鳳尾蕨Pteris fauriei Hieron.為日本、中國、琉球群島、臺灣及越南地區一普遍常綠性蕨類，在臺灣已被證實存在兩個分類群︰P. fauriei var. fauriei和P. fauriei var. minor Hieron.。兩者可藉由孢子大小、孢子囊內孢子數、藏精器內精子數、藏精器大小、生殖行為、及幼孢子體葉子形態來加以區別。測量U. Faurie在1904年所採及並被Hieronymus在1914年所發表的P. fauriei var. fauriei和P. fauriei var. minor模式標本之孢子大小，證實兩者分別為三倍體和二倍體。透過存活植株孢子囊內孢子數及蠟葉標本孢子大小，顯示兩種細胞型在臺灣的分布及其棲地類型：二倍體植株廣泛分布在臺灣及其鄰近島嶼，但未出現在臺灣中部或馬祖地區，相對地，三倍體植株未在台灣南部或台灣中部西側外島被發現，通常三倍體比二倍體生長在較高海拔地區及較冷涼的生育地。此二變種之atpB-rbcL非轉譯區間的基因序列完全一致，兩者該區段基因尚未發生分化現象。根據ISSR分子資料顯示大多數遺傳變異存在於族群之間，少數存在於族群之內。儘管P. fauriei var. fauriei行絕對無配生殖，卻有相當高的遺傳變異，多次獨立起源被視為無配生殖三倍體P. fauriei var. fauriei遺傳變異的主要來源。本研究證實三倍體Pteris fauriei var. fauriei與二倍體P. fauriei var. minor已分化出不同的細微特徵，顯著的生殖隔離模式，及分布和棲地類型的偏好；然而，P. fauriei var. fauriei和var. minor 卻無法由基因 (ISSR) 的相似性來加以區隔。

關鍵字

傅氏鳳尾蕨 ； 生殖生物學 ； 隱性特徵 ； 二倍體 ； 三倍體 ； 棲地 ； 遺傳變異

並列摘要

Pteris fauriei Hieron. is a very common, evergreen fern in Japan, China, the Ryukyu Islands, Taiwan and Vietnam. In Taiwan, two taxa, P. fauriei var. fauriei and P. fauriei var. minor Hieron. have been documented. These two varieties can be distinguished based on spore size, the number of spores in each sporangium, the number of sperm in each antheridium, antheridium size, reproductive behavior, and the morphology of juvenile sporophyte fronds. Using spore size, the type specimens of P. fauriei var. fauriei and P. fauriei var. minor, collected by U. Faurie in 1904 and published by Hieronymus in 1914, are able to be confirmed as triploid and diploid, respectively. Based on spore sizes and the number of spore per sporangium, the distribution and habitats of the two cytotypes in Taiwan are characterized from both living plants and herbarium specimens. Diploid plants distribute widely in Taiwan and nearby islands, but do not occur in central Taiwan or in the Matsu islands. In contrast, triploid plants are not found in southern Taiwan or on islands west of central Taiwan. In general, triploids grow at higher elevation and cooler habitat than the diploids. Both varieties have the same atpB-rbcL non-coding spacer sequence. No genetic differentiation between these two varieties in terms of this DNA sequence. ISSR molecular data shows that most genetic variations occur among populations and few within populations. Despite the nature of obligate apomictic of P. fauriei var. fauriei is detected, however, there is relative higher genetic variation in this variety than that in the diploid variety. Recurrent and independent origins are considered the major source of genetic variation of the apomictic triploid P. fauriei var. fauriei. This study documents that triploid Pteris fauriei var. fauriei and diploid P. fauriei var. minor have differentiated various cryptic characteristics, significant separation of reproductive modes, and the preference of their distribution and habitats. However, the genotypes of the P. fauriei var. fauriei and var. minor do not distinctly separate from each other based on the genetic similarity derived from ISSR DNA markers.

並列關鍵字

Pteris fauriei ； reproductive biology ； cryptic characteristic ； diploid ； triploid ； habitat ； genetic variation