昆欄樹之巢狀支序分析

Nested Phylogeographical Clade Analysis of Trochodendron aralioides (Trochodendraceae) in Taiwan

本文以Templeton及其同仁所研發出來之巢狀支序分析法推測形成昆欄樹在臺灣目前族群遺傳結構之可能原因。本文以葉綠體DNA之片段變異（包括petG-trnP及tranA-psbJ基因間隔區）檢視臺灣20族群，琉球2族群及日本2族群之基因型分布。巢狀支序分析推測臺灣之族群首先與日本族群分隔，各自演化。隨後族群遺傳結構由距離造成分隔（isolation by distance）現象所形塑。

Nested clade phylogeographical analysis (NCPA), developed by A. R. Templeton and his colleague, was used to infer the evolutionary events that shaped the spatial genetic structure of Trochodendron aralioides in Taiwan. Genetic variation of two intergenic spacers of chloroplast DNA (petG-trnP and trnA-psbJ) among 24 populations, in which two from Japan, two from the Ryukyus and 20 from Taiwan, was examined. The NCPA suggests that the populations in Taiwan were first isolated from those of Japan proper. Since then, the spatial genetic structure in Taiwan was attributable to restricted gene flow.