中文摘要
黃菀為菊科植物,全球約計1500種,主要分布於南美洲及非洲,臺灣有9個分類群,而分布於玉山國家公園境內的種類包括玉山黃菀(S.morrisonensis Hayata)、黃菀(S. nemorensis L. var. dentatus (Kitam.) H.Koyama)、台東黃菀(S. taitungensis S. S. Ying),及關山千里光 (S.Kuanshanensis C. –I Peng & S. W. Chung),並且均為台灣特有種,分類學者常以葉形、舌狀花大小及生長環境等作為千里光分類依據,但野外族群常見有難以分辨中間型,造成分類上的困難,本研究利用核ITS分子序列及微衛星DN分子指紋研究黃菀屬在玉山國家公園內的族群演化歷史,並界定種間分類地位,用以作為保育及研究依據。
核ITS 分子序列顯示這些種類皆未達到單系群,而微衛星DNA 和RAPD
結果顯示,玉山黃菀、黃菀、台東黃菀和關山千里光四個分類群可分成兩大群,一群為黃菀,另一群為玉山黃菀、台東黃菀和關山千里光,形態的多變、各族群間高度分化的情況,顯現這些漸變群主要是近代棲地隔離,族群間歧異。
英文摘要
The development of molecular biology has promoted systematics, and conservation biology. In this study, we examined the taxonomic status and conservation genetics of the Senecio morrisonensis Hayata species complex, including S. morrisonensis, S. nemorensis L. var. dentatus (Kitam.) H. Koyama, S. taitungensis S. S. Ying, and S. kuanshanensis C.-I Peng & S. W. Chung, all of which are distributed in the Yu-shan National Park. Phylogenetic analysis based on nuclear ribosomal ITS sequences revealed that all taxa are paraphyletic. Microsatellite DNAs and RAPD fingerprints separated these species into two groups, i.e., a group of S. nemorensis var. dentatus, and the other including S. morrisonensis, S. taitungensis and S. kuanshanensis. A erarchical AMOVA analyses indicated significant genetic differentiation among populations (FST=0.52;P<0.05). Highly variable morphologies, and population differentiation reflex a scenario of recent divergence.