The chloroplast gene matK and the internal transcribed spacers (ITS) of the nuclear ribosomal DNA from Schnabelia, a genus endemic to China, and 6 genera of Verbenaceae and 13 genera of Lamiaceae were sequenced. The p...The chloroplast gene matK and the internal transcribed spacers (ITS) of the nuclear ribosomal DNA from Schnabelia, a genus endemic to China, and 6 genera of Verbenaceae and 13 genera of Lamiaceae were sequenced. The phylogenetic signal and validity outgroups were measured and evaluated by means of the relatively apparent synapomorphy analysis (RASA). Independent and combined phylogenetic analyses for the matK and ITS sequences were performed using the maximum parsimony (MP), neighbor- joining (NJ) and maximum likelihood (ML) methods, indicating that Schnabelia oligophylla and Caryopteris terniflora form a sister-group relationship. The Caryopteris complex is not shown to be a monophyly because Trichostema, C. paniculata and C. forrestii are paraphyletic to the clade containing the remaining members of the complex. A monophyly of Ajugoideae proposed by Cantino et al., including 8 genera in this study, is strongly supported and the closest relatives of Schnabelia are in the Ajugoideae (Lamiaceae), especially near Caryopteris terniflora. The polygenetic analyses also showed that the genera of Lamiaceae and Verbenaceae sampled in this tudy are phylogenetically mixed and the genus Avicennia is distant to other genera of Verbenaceae. RASA and combined analysis can be used as effective approaches to determining the relationships among phylogenetically complex groups.展开更多
The chloroplast genes matK and rbcL, ribo- somal gene 18S and ITS regions of nuclear ribosomal DNA from Ephedra rhytidosperma, a species endemic to China, were sequenced and its phylogenetic position was investi- gate...The chloroplast genes matK and rbcL, ribo- somal gene 18S and ITS regions of nuclear ribosomal DNA from Ephedra rhytidosperma, a species endemic to China, were sequenced and its phylogenetic position was investi- gated. Independent and combined phylogenetic analyses for the DNA sequences from 16 taxa representing 15 species of the genus Ephedra were performed using the maximum par- simony (MP), neighbor-joining (NJ), minimum evolution (ME) and maximum likelihood (ML) methods. The results indicate that E. rhytidosperma is closely related to E. equiset- ina. The divergence time between them is estimated to be 10.85±2.44 Ma based on the results of the relative-rate tests and the evolutionary rate of rbcL gene.展开更多
基金supported by funds from the Arnold Arboretum of Harvard University for fieldwork in the U.S.A.the National Science Foundation for Distinguished Young Scholars(Grant No.39825104)+2 种基金the National Natural Science Foundation of China(Grant Nos.30070053,30170071 and 30230030)the Natural Science Foundation of Guangdong Province(Grant No.001223)the Ministry of Education Special Foundation(Grant No.20010558013).
文摘The chloroplast gene matK and the internal transcribed spacers (ITS) of the nuclear ribosomal DNA from Schnabelia, a genus endemic to China, and 6 genera of Verbenaceae and 13 genera of Lamiaceae were sequenced. The phylogenetic signal and validity outgroups were measured and evaluated by means of the relatively apparent synapomorphy analysis (RASA). Independent and combined phylogenetic analyses for the matK and ITS sequences were performed using the maximum parsimony (MP), neighbor- joining (NJ) and maximum likelihood (ML) methods, indicating that Schnabelia oligophylla and Caryopteris terniflora form a sister-group relationship. The Caryopteris complex is not shown to be a monophyly because Trichostema, C. paniculata and C. forrestii are paraphyletic to the clade containing the remaining members of the complex. A monophyly of Ajugoideae proposed by Cantino et al., including 8 genera in this study, is strongly supported and the closest relatives of Schnabelia are in the Ajugoideae (Lamiaceae), especially near Caryopteris terniflora. The polygenetic analyses also showed that the genera of Lamiaceae and Verbenaceae sampled in this tudy are phylogenetically mixed and the genus Avicennia is distant to other genera of Verbenaceae. RASA and combined analysis can be used as effective approaches to determining the relationships among phylogenetically complex groups.
基金supported by the Chinese National Key Project for Basic Research(“973"”)(2003CB715904)the National Natural Science Foundation of China(Grant Nos.30230030&30370105).
文摘The chloroplast genes matK and rbcL, ribo- somal gene 18S and ITS regions of nuclear ribosomal DNA from Ephedra rhytidosperma, a species endemic to China, were sequenced and its phylogenetic position was investi- gated. Independent and combined phylogenetic analyses for the DNA sequences from 16 taxa representing 15 species of the genus Ephedra were performed using the maximum par- simony (MP), neighbor-joining (NJ), minimum evolution (ME) and maximum likelihood (ML) methods. The results indicate that E. rhytidosperma is closely related to E. equiset- ina. The divergence time between them is estimated to be 10.85±2.44 Ma based on the results of the relative-rate tests and the evolutionary rate of rbcL gene.
