拟单性木兰属近缘植物matK基因的序列分析

Phylogeny of Parakmeria (Magnoliaceae) and Its Related Taxa Inferred from the mat K Gene Sequence

测定了木兰科（Ｍａｇｎｏｌｉａｃｅａｅ）拟单性木兰属（Ｐａｒａｋｍｅｒｉａ）等１０种（１１个样）植物的叶绿体ＤＮＡｍａｔＫ基因部分序列（１０３９碱基对）．最大同源性分析构建的系统树图建议：①拟单性木兰属与单性木兰属（Ｋｍｅｒｉａ）有极近的同源关系；②木兰属（Ｍａｇｎｏｌｉａ）的玉兰亚属（ＳｕｂｇｅｎｕｓＹｕｌａｎｉａ）与拟单性木兰属和单性木兰属关系亦很近，并形成１个单系分支；而木兰属的２个亚属，木兰亚属（ＳｕｂｇｅｎｕｓＭａｇｎｏｌｉａ）与玉兰亚属之间的关系却较远，木兰属内呈并系演化特征；③木兰亚属，木莲属（Ｍａｎｇｌｉｅｔｉａ）以及玉兰亚属、拟单性木兰属和单性木兰属所组成的分支形成一个单系分支．拟单性栏属、单性木兰属的系统位置。

The 1 039 bp sequences of the chloroplast mat K gene from nine species (ten samples) relating to Parakmeria and Kmeria of Magnoliaceae were determined The phylogenetic tree based on Parsimony analysis suggested:① The three species of Parakmeria and the two samples (including male and female) of Kmeria were highly homologious, which indicated a very close relationships among them;② the Subgenus Yulania of Magnolia was shown very closely to Parakmeria and Kmeria (the sequence divergences among them were 3～6 in 1 039 bps), and they formed a monophyletic clade However there is a rather far relationship between the two subgenera Subgenus Yulania and Subgenus Magnolia (the sequence divergence was 13), which was suggested to be paraphyletic; ③ the monophyly was strongly supported among the Subgenus Magnolia, Manglietia and the clade of Magnolia Subgenus Yulania, Parakmeria and Kmeria The phylogenetic position of Parakmeria and Kmeria ,and the rrelationships among them and Magnolia need to be re considered.