%0 Journal Article
%T Aian origin for Polystichum (Dryopteridaceae) based on rbcL sequences<br>Asian origin for Polystichum （Dryopteridaceae） based on rbcL sequences
%A Chunxiang Li
%A Shugang Lu
%A Qun Yang
%A <br>LIChunxiang
%A LUShugang
%A YANGQun
%J 科学通报(英文版)
%D 2004
%I 
%X Chloroplast rbcL sequences of 60 species of Polystichum sensu lato (s.l.), including 23 new sequences from southwest China, were used to assess the phylogenetic relationships within the genus. On the basis of estimated evolution rate of rbcL gene and the genetic distance data that passed relative-rate tests, we further estimated the divergence times between some clades of the genus. The phylogenetic relationships were inferred using the neighborjoining and maximum-parsimony methods, both methods producing trees with completely congruent topology. These trees reveal that all species of Polystichum s.l. in this study (including Cyrtomium and Cyrtomidictyum) form a monophyletic group. The basal split in Polystichum s.l. separates a clade with all Asian members from a clade containing other species from all over the world. The phylogenetic and divergence time estimation results lead us to suggest that Polystichum s.l. originated in Asia in the late Late Cretacous (≈76 Ma) and migrated into other places in the world in early Eocene (≈ 46 Ma).
%K Polystichum
%K rbcL
%K phylogeny
%K origin
%K divergence time<br>亚洲起源
%K 系统发育
%K 分歧时间
%K rbcL
%K 基因序列
%K 耳蕨
%U http://www.alljournals.cn/get_abstract_url.aspx?pcid=01BA20E8BA813E1908F3698710BBFEFEE816345F465FEBA5&cid=96E6E851B5104576C2DD9FC1FBCB69EF&jid=DD6615BC9D2CFCE0B6F945E8D5314523&aid=32C24D4E14842C22CB82F3DBF297FC9F&yid=D0E58B75BFD8E51C&vid=2A3781E88AB1776F&iid=708DD6B15D2464E8&sid=D542ADE6529F4059&eid=19E8BB8BE90732B2&journal_id=1001-6538&journal_name=科学通报(英文版)&referenced_num=8&reference_num=14