细鳞苔科psbA基因适应性进化分析_陈晓霞.pdfVIP

西北植物学报, 2010, 30(8):1534- 1544 Acta Bot.Boreal .-Occident.Sin . ① 　　:1000-4025(2010)08-1534-11 p sbA 1 1 2 陈晓霞, 苏应娟 , 王　艇 (1 中山大学生命科学学院, 广州510275 ;2 中国科学院武汉植物园湿地演化与生态恢复湖北省重点 验室, 武汉430074) 　:在时间框架下, 采用机理式模型(Mechanistic model)和MEC 模型(Mechanistic-empirical combination mod- el)以及Datamonkey 对细鳞苔科p sbA 基因的进化式样进行了分析.结果均未检测到统计上显著的正选择位点, 显 示负选择对细鳞苔科p sbA 基因起主导作用.另外, 基于UC D 分子钟估算出的细鳞苔科各分支分歧时间表明, 该 科物种丰富度的辐射式增长发生在新生代渐新世. :细鳞苔科;p sbA 基因;分歧时间;正选择;负选择 :Q949.35 :A AdaptiveEvolutionAnalysis of thep sbA GeneinLejeuneaceae 1 1 2 CHEN Xiao-xia , SU Ying-juan , WANG Ting (1 School of ife Sciences, Sun Yat-Sen Univer sity, Guangzhou 510275, China ;2 Hubei Key aboratory of Wetland Evolution Ecological Restoration, Wuhan Botanical Garden, Chinese Academy of Sciences, Wuhan 430074, China) Abstract :The evolutionary patterns of the p sbA gene sequences in ejeuneaceae were examined by using the Mechanistic model, the Mechanistic-empirical combination (MEC)model and Datamonkey along with the estimated time-scale of the ejeuneaceae phylogeny.N o significant positively selected sites were detec- ted under any models, showing that negative selection has played a dominant role for the evolution of the p sbA gene in ejeuneaceae.In addition, the phylogenetic tree reconstructed with uncorrelated lognormal distributed relaxed clock model further demonstrated that the radiation of the ejeuneaceae species richness occurred within the Oligocene period.These results provided useful information for understanding