Abstract:
Castanopsis chinensis (Spreng.) Hance is widespread in the subtropical forests of China. Castanopsis qiongbeiensis G.A. Fu and Castanopsis glabrifolia J. Q. Li & Li Chen are limited to the coastal beaches of Wenchang county in the northeast of Hainan Island, and have similar morphological characteristics to C. chinensis. It is supposed that C. qiongbeiensis and C. glabrifolia are closely related to C. chinensis. In the present study, the genetic differentiation, gene flow, and genetic relationship of C. chinensis, C. qiongbeiensis, and C. glabrifolia were investigated by using 15 nuclear microsatellite markers; a total of 308 individuals from 17 populations were sampled in the three species. The allelic variation of nuclear microsatellites revealed moderate but significant genetic differentiation (FCT = 0.076) among C. chinensis, C. qiongbeiensis, and C. glabrifolia, and genetic differentiation between C. chinensis and C. glabrifolia was larger than that between C. chinensis and C. qiongbeiensis. Demographic simulations revealed unidirectional gene flow from C. chinensis to C. glabrifolia and C. qiongbeiensis, which highlight dispersal from mainland to island. The isolation effect of Qiongzhou Strait increased the genetic differentiation of species on both sides of the strait; however, the differentiation was diminished by gene flow that occurred during the historical period when Hainan Island was connected to mainland China. Our results supported the argument that C. glabrifolia should be considered an independent species and argued that C. qiongbeiensis should be regarded as an incipient species and independent conservation unit.
摘要:
栗子(散播。)汉斯在中国亚热带森林中普遍存在。琼北con和glabrifoliaJ.Q.Li和李晨仅限于海南岛东北部文昌县的沿海海滩,并具有与C.chinensis相似的形态特征。据推测,琼北树和光叶C.与中国C.密切相关。在本研究中,遗传分化,基因流,和中国菜的遗传关系,C.琼北,使用15个核微卫星标记研究了光叶C.。在这三个物种中,共有来自17个种群的308个个体进行了采样。核微卫星的等位基因变异揭示了C.chinensis之间中等但显着的遗传分化(FCT=0.076),C.琼北,和C.glabrifolia,中华毛节菜和光叶毛节菜的遗传分化大于中华毛节菜和琼北毛节菜的遗传分化。人口统计模拟显示,从中国菜到光叶菜和琼北菜的单向基因流,这突出了从大陆到岛屿的扩散。琼州海峡的隔离效应增加了海峡两岸物种的遗传分化;然而,在海南岛与中国大陆相连的历史时期发生的基因流减少了分化。我们的结果支持应将C.glabrifolia视为独立物种的论点,并认为C.琼北应被视为初期物种和独立的保护单位。