基于核rDNA ITS序列的繁缕族疑似种分子鉴定  

Molecular identification of suspected alsineae species based on nuclear rDNA ITS sequences

作　　者：刘瑾[1] 吴耘珂[1] 马子驭[1] 何兴金[1] 

机构地区：[1]四川大学生命科学学院,成都610064

出　　处：《四川大学学报（自然科学版）》2007年第5期1101-1110,共10页Journal of Sichuan University(Natural Science Edition)

基　　金：国家自然科学基金(30670146);科技部自然科技资源平台项目(2005DKA21403)

摘　　要：在中国植物志二十六卷中,花柱数目是划分繁缕族(Alsineae)的鹅肠菜属(Myoso-ton)、卷耳属(Cerastium)、繁缕属(Stellaria)等8属的重要检索项.作者在成都附近采集了6号繁缕族疑似种标本,其花柱数目等形态特征混淆,无法鉴定属种.采用核rDNA中的ITS序列对石竹科(Caryophyllacaea)特别是繁缕族进行分子系统分析并据此对疑似种进行分子鉴定.最大简约法和邻接法分析结果均显示,繁缕族疑似种与鹅肠菜(Myosoton aquaticum)聚合成一支.在与无花菜属植物Arenaria racemosa的ITS序列进化速率比较后表明,疑似种均为鹅肠菜,其形态差异应属于种下变化范围,且居群之间存在花柱数目由5向3减少的演化趋势.Style number was an important character to distinguish 8 genera of Alsineae including Myosoton, Cerastiurn, Stellaria, etc. according to Flora of China Vol. 26.6 specimens of suspected Alsineae plants were collected around Chengdu and could not be identified by the style number and other morphological characters. The rDNA ITS sequences were used to reconstruct the phylogeny of Caryophyllaceae （especially Alsineae） in order to identify the suspected plants. The results of both maximum parsimony and distance methods grouped the suspected plants with Myosoton aquaticurn. The comparison of ITS nucleotide substitution rate in 3 Arenaria racemosa voucher specimens and the 6 suspected Alsineae specimens indicated that all the unknown plants are Myosoton aquaticurn with intraspecific morphological variations. Furthermore, there is a trend of style number reduction from 5 to 3 among the populations of M. aquaticurn.

关 键 词：系统发育 分子鉴定 疑似种 繁缕族 

分 类 号：Q949[生物学—植物学]