台灣產車前車石龍尾屬之分類研究
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Date
2013
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Abstract
本研究利用外部形態、種子與花粉微細形態及分子親緣關係等資料,進行台灣產石龍尾屬(Limnophila)植物之分類研究。結果認為台灣共產11種石龍尾,其中重新界定無柄花石龍尾(L. sessiliflora)並確認其在台灣歸化,並從中分出新種東方石龍尾(L. orientalis sp. nov.)為台灣原生種,另再確認石龍尾(L. trichophylla)之學名正確性而分出新種絲葉石龍尾(L. taiwanensis sp. nov.),另有新種屏東石龍尾(L. pingtungensis sp. nov.)。外部形態上,葉脈、葉形、萼片、蒴果等為石龍尾屬植物的重要分類特徵,另外種子表面微細形態在節間與少數種間具差異,支持節的歸群,亦可作為分類鑑定之參考。分子研究取樣台灣產與部分國外材料共19種,外群選擇Gratiola和車前屬(Plantago)做為外群,並使用葉綠體DNA之trnL-F、trnG、ndhF序列進行本屬之親緣關係研究,合併各片段後得到總資料矩陣共3,677 bp。親緣關係樹顯示台灣產石龍尾屬可分為三大支系,此三大支系與沉水裂葉有無、葉脈平行脈或羽狀脈及蒴果成熟時萼片具條紋與否等特徵一致,支持前人研究建立之Limnophila節、Striatae節為支持度極高的單系群,而前人置於Integrifolieae節之L. fragrans則與Striatae節形成姊妹群,應排除於Integrifolieae節之外。
The genus Limnophila (Plantaginaceae) in Taiwan is taxonomically revised based on morphological, palynological, and molecular biological studies. The result shows that 11 species of this genus are indigenous to Taiwan, which include 3 new species, L. pintungensis sp. nov., L. taiwanensis sp. nov. and L. orientalis sp. nov. The new species L. orientalis is divided from the re-circumscribed L. sessiliflora which is also confirmed here to be a newly naturalized species in Taiwan. The new species L. taiwanensis sp. nov. which was considered as L. trichophylla before is extracted from the re-recognized L. trichophylla. The morphology of venation, leaf shape, calyx, and capsule are the important characters for the classification of Taiwanese genus. Furthermore, the seed surfaces also provide evidences for distinguishing sections and some species. Finally, the phylogenetic relationship within this genus was studied using the cpDNA markers trnL/F, trnG, and ndhF from 19 species sampled in Taiwan and neighboring area. Gratiola and Sesamum are chosen as outgroups. The cladogram of molecular phylogeny revealed three separate lineages corresponding to the sectional grouping of previous studies and could be distinguished by the finely dissected submerged leaves, venation, and calyx striation on mature fruits. The section Limnophila and section Striatae are highly supported monophyletic groups, but section Integrifolieae shows paraphyly.
The genus Limnophila (Plantaginaceae) in Taiwan is taxonomically revised based on morphological, palynological, and molecular biological studies. The result shows that 11 species of this genus are indigenous to Taiwan, which include 3 new species, L. pintungensis sp. nov., L. taiwanensis sp. nov. and L. orientalis sp. nov. The new species L. orientalis is divided from the re-circumscribed L. sessiliflora which is also confirmed here to be a newly naturalized species in Taiwan. The new species L. taiwanensis sp. nov. which was considered as L. trichophylla before is extracted from the re-recognized L. trichophylla. The morphology of venation, leaf shape, calyx, and capsule are the important characters for the classification of Taiwanese genus. Furthermore, the seed surfaces also provide evidences for distinguishing sections and some species. Finally, the phylogenetic relationship within this genus was studied using the cpDNA markers trnL/F, trnG, and ndhF from 19 species sampled in Taiwan and neighboring area. Gratiola and Sesamum are chosen as outgroups. The cladogram of molecular phylogeny revealed three separate lineages corresponding to the sectional grouping of previous studies and could be distinguished by the finely dissected submerged leaves, venation, and calyx striation on mature fruits. The section Limnophila and section Striatae are highly supported monophyletic groups, but section Integrifolieae shows paraphyly.
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水生植物, 石龍尾, 車前科, 分類研究, 分子親緣關係, Aquatic plants, Limnophila, Plantaginaceae, Taxonomy, Phylogeny