應用ISSR分子標誌探討台灣產香桂（樟科）之遺傳變異

Genetic Variation of Cinnamomum subavenium Miq. (Lauraceae) in Taiwan Using ISSR Markers

香桂（Cinnamomum subavenium Miq.）為樟科（Lauraceae）樟屬（Cinnamomum）之重要原生樹種，本研究應用簡單重複序列（Inter-Simple Sequence Repeat, ISSR）分子指紋技術，探討其族群的遺傳變異與親緣關係。分析臺灣自然分佈之9地區72個樣本，使用了17個ISSR引子進行聚合鏈鎖反應（Polymerase chain reaction；PCR）得到150個條帶，其中多型性條帶有78條（52%）。分子變方分析（AMOVA）結果，族群間之變方成分是16.45%（p＜0.001），族群內的變方成分是83.55%（p＜0.001），族群遺傳變異成分來自於族群內。POPGENE分析結果顯示，族群Nei's基因歧異度值為0.3944，遺傳分化指數（Gst）為0.3642，基因流（Nm）為0.8730。歸群分析與主座標分析結果無地理親緣關聯，推測為生育環境之差異，族群基因流受限制，具有較高的基因歧異度與遺傳分化現象。 Cinnamomum subavenium Miq. is an endemically important species in Taiwan belongingto the genus of Cinnamomum in Lauraceae family. In the present study as ISSR molecular markersand 17 corresponding primers were applied, 72 individuals collected from 9 sampling sites aroundTaiwan were studied and resulted in a total of 150 bands. Among them, 78 bands were polymorphic(52%) . Analysis of Molecular Variance (AMOVA) revealed that the component of variance amongpopulations was 16.45% (p ＜ 0.001) and was attributed to the population differentiation. The mainvariance was counted 83.55% due to differentiation within populations; this main variance withinpopulations was shown to be highiy significant (p ＜ 0.001). Analysis of the population geneticvariances (Popgene) demonstrated that there are remarkable genetic diversity ( genetic diversity：0.3944, Gst：0.3642) and low level of gene flow (Nm：0.8730). The results of this analysis wereprobably due to the influence from the different environment that has not restricted the gene flow but higher promote a higher genetic differentiation. Cluster analysis and Principal Coordinate analysis(PCOA) similarly revealed that the genetic differentiation may be caused by different environmentswhile habitat influences and space order are not be corresponding to the geographical relationships.

Cinnamomum subavenium Miq. is an endemically important species in Taiwan belongingto the genus of Cinnamomum in Lauraceae family. In the present study as ISSR molecular markersand 17 corresponding primers were applied, 72 individuals collected from 9 sampling sites aroundTaiwan were studied and resulted in a total of 150 bands. Among them, 78 bands were polymorphic(52%) . Analysis of Molecular Variance (AMOVA) revealed that the component of variance amongpopulations was 16.45% (p ＜ 0.001) and was attributed to the population differentiation. The mainvariance was counted 83.55% due to differentiation within populations; this main variance withinpopulations was shown to be highiy significant (p ＜ 0.001). Analysis of the population geneticvariances (Popgene) demonstrated that there are remarkable genetic diversity ( genetic diversity：0.3944, Gst：0.3642) and low level of gene flow (Nm：0.8730). The results of this analysis wereprobably due to the influence from the different environment that has not restricted the gene flow but higher promote a higher genetic differentiation. Cluster analysis and Principal Coordinate analysis(PCOA) similarly revealed that the genetic differentiation may be caused by different environmentswhile habitat influences and space order are not be corresponding to the geographical relationships.