台灣產剪股穎屬植物分類研究

Abstract

本研究利用外部形態、地理分布和葉綠體DNA trnL-rpl32 intergenic spacer序列，研究台灣產剪股穎屬植物。外部形態結果發現，外稃芒的有無、基盤毛的有無、內稃長度及花藥的長度是重要的區別特徵，花序和植株習性也可提供部分分類的參考；本研究尚依其他證據將台灣產剪股穎屬分成9個分類群：A. arisan-montana Ohwi、A. avenaceae Gmel.、A. clavata Trin.、A. dimorpholemma Ohwi、A. fukuyamae Ohwi、A. infirma Buse、A. sonzanensis Hayata、Agrostis stolonifera L.及A. transmorrisonensis Hayata。 分子資料經排序得到787鹼基的資料，而葉綠體DNA序列最大簡約法和相鄰連接法結果非常接近，建構的親緣關係樹大致與形態分類的結果一致，且各分支均有不錯的支持度。但根據過往形態特徵鑑定的A. sozanensis Hayata，則顯示為多系群，經重新檢視標本，將A. transmorrisonensis Hayata重新自A. sozanensis Hayata分出。此外A. arisan-montana Ohwi、A. fukuyamae Ohwi、A. infirma Buse和A. sonzanensis Hayata等4類群，在親緣關係上並不為單系群，故不支持Veldkamp將其視為同種內不同變種的分類處理，因此將此4類群全部回復為原始發表時的種的階級。

The genus Agrostis Linneaus (Poaceae) in Taiwan is taxonomically revised base on morphological, phytogeographical and molecular phylogenetical studies. Occurence of lemma awn, callus vesture, and length of palea and anther are important characters for the classification of Taiwanese taxa. The Inflorescence and culm habit also provide useful application for distinguishing some taxa in Taiwan. In the study, Nine taxa in Taiwan were recognized, including A. arisan-montana Ohwi、A. avenaceae Gmel.、A. clavata Trin.、A. dimirpholemma Ohwi、A. fukuyamae Ohwi、A. infirma Buse、A. sonzanensis Hayata、Agrostis stolonifera L. and A. transmorrisonensis Hayata. In a phylogenetic analysis based on the Chloroplast DNA sequence of the trnL-rpl32 intergenic spacer, 787 bps sequencing data was obtained. The topologies of maximum parsimony tree and neighbor-joining tree were similar. The phylogenetical relationships of Taiwanese taxa were conformed with great supported to the morphological differentiation. However, A. sozanensis Hayata was paraphyly. After observing morphology of vouchers again, A. transmorrisonensis Hayata was re-divided from A. sozanensis Hayata. Besides, A. arisan-montana Ohwi、A. fukuyamae Ohwi、A. infirma Buse and A. sonzanensis Hayata were not monophyly, it was not supported Veldkamp treatment to sorted the four taxa in a variety rank of a same species. For the former phylogenetic result, to restore the four taxa to original species ranks.