摘要
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psbA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psbA基因起主导作用.另外,基于UCLD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.
The evolutionary patterns of the psbA gene sequences in Lejeuneaceae were examined by using the Mechanistic model,the Mechanistic-empirical combination（MEC） model and Datamonkey along with the estimated time-scale of the Lejeuneaceae phylogeny.No significant positively selected sites were detected under any models,showing that negative selection has played a dominant role for the evolution of the psbA gene in Lejeuneaceae.In addition,the phylogenetic tree reconstructed with uncorrelated lognormal distributed relaxed clock model further demonstrated that the radiation of the Lejeuneaceae species richness occurred within the Oligocene period.These results provided useful information for understanding the evolution of chloroplast genes in Lejeuneaceae.
出处
《西北植物学报》
CAS
CSCD
北大核心
2010年第8期1534-1544,共11页
Acta Botanica Boreali-Occidentalia Sinica
基金
国家自然科学基金(30771763,30970290)
中国科学院知识创新工程重要方向项目(KSCX2-YW-Z-0940)
关键词
细鳞苔科
PSBA基因
分歧时间
正选择
负选择
Lejeuneaceae
psbA gene
divergence time
positive selection
negative selection
