锦鸡儿属(豆科)祖先分布区分析

锦鸡儿属(Caragana)是一个温带亚洲分布属.在我们对这一属系统发育树以及13个分布区的基础上,重点采用Bremer(1992),Ronquist(1994)和Hausdorf(1997)提出的方法,进行本属祖先分布区的分析和探讨.结果表明,3种方法均表明远东-我国东北,阿尔泰-萨彦岭以及华北-秦岭是可能的祖先分布区.结合北温带植物类群属的北方起源学说,认为远东-我国东北为原始分布区的可能性更大一些.同时这三个分布区彼此地理上是隔离的,也恰是本属内一个较原始种树锦鸡儿(Caragana arborescens)的分布区,结合我们以前的分析生物地理学研究,认为隔离分化是本属最重要的物种形成方式,扩散是次要的而且是短距离的扩散.

Ancestral Area Analysis of the Genus Caragara (Leguminosae)

Caragana has a temperate Asian distribution. Based on the phylogeny and 13 distributional areas of this genus, its ancestral area was studied via the ancestral area analysis suggested by Bremer (1992), Ronquist (1994) and Hausdorf (1997). The results indicate that three areas, Far East-Northeast China, Altai-Sayan and North China-Qinling Mountains (Mts) are likely the ancestral areas. Linking to the viewpoints of the Holarctic origin for north temperate flora, Far East-Northeast China seems more likely to be the ancestral area. According to the three ancestral areas isolated geographically and the analysis in the present study, as well as former biogeographical analysis of this genus, it is suggested that Caragana speciation is mainly in the mode of vicariance rather than dispersal, and dispersed is often in short distance.