据叶绿体trnL—F序列分析“高等”金缕梅类植物的系统发育关系

研究对“高等”金缕梅类的 8科 2 4属 2 5种植物和外类群Hamamelis两种植物的叶绿体DNAtrnL_F区进行了测序 ,并根据DNA序列对该类植物的系统发育关系进行了分析。结果表明 :所有“高等”金缕梅类植物的科结合成一支 ,bootstrap分析支持率为 10 0 % ,各科之间的关系得到很好分辨。Nothofagus是最基部的一支 ;山毛榉科 (Fa gaceae)作为姐妹群与“核心”金缕梅类的科 (桦木科Betulaceae ,胡桃科Juglandaceae ,木麻黄科Casuarinaceae ,杨梅科Myricaceae,Ticodendraceae和马尾树科Rhoipteleaceae)组成一支 ,并得到很强的支持。“核心”金缕梅类构成三支 ,关系如下 :(1)Casuarina (Ticodendron ,(Betulaceae) ) ,(2 )Juglandaceae_Rhoipteleaceae ,(3)Myricaceae。本研究显示叶绿体DNAtrnL_F区对分辨“高等”金缕梅类科间关系及部分科内的属间关系十分有效。

Phylogenetic Relationships of the "Higher" Hamamelids Based on Chloroplast trn L-F Sequences

Phylogenetic relationships of the "higher" hamamelids were estimated based on nucleotide sequences of the non_coding region of chloroplast trn L_F. Twenty_five species were sampled, representing 24 genera of all eight families of the "higher" hamamelids. A parsimony analysis of data set indicated that the "higher" hamamelids formed a strongly supported clade with 100% bootstrap value in the strict consensus tree. Nothofagus was the basal lineage and the Fagaceae was sister to a well_supported core "higher" hamamelids clade containing Myricaceae, Rhoipteleaceae, Juglandaceae, Casuarinaceae, Ticodendraceae and Betulaceae. Three clades were recognized in the core "higher" hamamelids: (1) Casuarina (Ticodendron, (Betulaceae)), (2) Juglandaceae_Rhoipteleaceae, and (3) Myricaceae. Compared with the previous studies, familial relationships of the "higher" hamamelids were better resolved.