Genetic Variation of the Endangered Scaevola hainanensis (Goodeniaceae) in the Jiangjun Stream Mouth, Taiwan

海南草海桐在台灣為嚴重瀕臨滅絕的植物，本種植物分布於台南縣將軍溪口6條彼此相通的水溝間，覆蓋面積不及l公頃。本研究應用Inter-simple sequence repeat (ISSR)研究海南草海桐之遺傳變異，從這6條水溝共採集50個樣本，共使用了27個ISSR引子，並得到233個條帶，但僅獲得6個多型性條帶(2.58%)，此結果顯示本植物在臺灣具非常低的遺傳變異。經過分子變方分析(AMOVA)顯示海南草海桐有93.85％的變方成分存在於個體間；POPGENE分析結果顯示其遺傳分化係數(G(下標 ST))為0.172，而基因流(Nm)為2.4，顯示溝渠並無阻礙基因交流之能力；UPGMA歸群分析及主座標分析結果顯示海南草海桐個體間幾乎無差別或差異很小。由於海南草海桐在台灣的生育地僅於一處狹隘且人工干擾嚴重之地，若遭受破壞則海南草海桐馬上會面臨滅絕的命運，故在保育方式上選擇區外保育較為恰當。

關鍵字

海南草海桐；草海桐科；簡單序列重複區間；分子變方分析；保育；台灣；遺傳多樣性

並列摘要

Scaevola hainanensis Hance is an endangered plant species in Taiwan. Distribution of this species in Taiwan is restricted to 6 connected ditches, which cover an area smaller than 1 ha at the estuary of Jiangjun Stream, Tainan County, southwestern Taiwan. We examined the genetic variation with inter-simple sequence repeat (ISSR) fingerprints. Fifty samples from 6 ditches were collected. In total, 27 primers were used, and 233 bands were obtained, of which only 6 bands (2.58%) were polymorphic, indicating low levels of genetic variation. The analysis of molecular variance (AMOVA) revealed that 93.85% of the variance component was attributable to the variation among individuals within ditches. Low levels of the genetic differentiation coefficient among ditches, G(subscript ST)=0.172 and Nm=2.4, indicated that the ditches barely hinder gene flow between Scaevola populations. UPGMA cluster analysis and principal coordinate analysis revealed no major groupings among ditches or among plants. If the present habitat is damaged, the species will inevitably be confronted with extirpation from Taiwan. Therefore, we suggest that ex situ conservation should be conducted in order to enlarge the population size.

並列關鍵字

Scaevola hainanensis ； Goodeniaceae ； ISSR ； AMOVA ； conservation ； Taiwan ； genetic diversity.

國際替代計量

Genetic Variation of the Endangered Scaevola hainanensis (Goodeniaceae) in the Jiangjun Stream Mouth, Taiwan

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