依RAPD標誌推論台灣杉屬之遺傳多樣性

Genetic Diversity in Genus Taiwania Inferred from RAPD Markers

本研究以逢機擴大多型性（RAPD）來進行台灣杉屬植物之遺傳變異分析：禿杉材料採自中國大陸福建屏南、貴州雷公山以及雲南騰衝；台灣杉的材料則來自六龜研究中心20林班台灣杉單親後裔試驗林木之雪山、望鄉及關山三個族群之種源，並以柳杉作為群外對照。RAPD電泳以POPGENE套裝軟體進行族群遺傳變異之相關分析，結果顯示台灣杉之關山和望鄉地區族群的相似性指數最高，為0.9645，雪山和望鄉地區之相似性指數次之；而中國大陸地區之禿杉族群則以貴州和雲南之族群相關係數0.9228最高，福建和貴州地區族群之0.9050次之。依據樹狀圖分析，禿杉與台灣杉之類群雖可以清楚的區分兩個類群，但兩類群之聯結點僅在11.1，顯見兩類群有非常大之相似性。中國大陸禿杉的遺傳歧異度為0.1744低於台灣杉之0.2271，兩者總歧異度為0.2709，數值偏低。本研究用UPGMA樹枝狀圖得出兩類群間之遺傳相似度為0.8890，仍在種內族群間內之變異範圍，應可列於同一種群之下，但兩者之間的基因流Nm值低於1，為0.7553，顯示禿杉和台灣杉之間有基因交流的障礙存在，而兩者亦顯示禿杉和台灣杉之仍具有可資區別之定量及定性形態特徵。 Genetic variation of the genus Taiwania was studied using RAPD markers. Sampling ofTaiwania flousiana Gaussen was made in its natural distribution areas, i.e. Fu-Jien, Guei-Jou and Yun-zGuei-Jou and Yun-nan was 0.9228, between Fu-Jien and Guei-Jou 0.9050. The genetic diversity of T.flousiana was 0.1724, lower than that of T. cryptomerioides which was 0.2771. When pooling together,the genetic diversity was 0.2709. Based on the UPGMA phonogram, T. cryptomerioides and Taiwaniaflousiana could be divided into 2 different clusters. The SI between two species was as high as 0.8890,within the range of species level, suggesting they can be treated as the same species. However, Nm inthe genus was as low as 0.7553. Besides, two taxa they still have consistent morphological difference,which can be used to distinguish each from other.

Genetic variation of the genus Taiwania was studied using RAPD markers. Sampling ofTaiwania flousiana Gaussen was made in its natural distribution areas, i.e. Fu-Jien, Guei-Jou and Yun-zGuei-Jou and Yun-nan was 0.9228, between Fu-Jien and Guei-Jou 0.9050. The genetic diversity of T.flousiana was 0.1724, lower than that of T. cryptomerioides which was 0.2771. When pooling together,the genetic diversity was 0.2709. Based on the UPGMA phonogram, T. cryptomerioides and Taiwaniaflousiana could be divided into 2 different clusters. The SI between two species was as high as 0.8890,within the range of species level, suggesting they can be treated as the same species. However, Nm inthe genus was as low as 0.7553. Besides, two taxa they still have consistent morphological difference,which can be used to distinguish each from other.