Studies on Systematics of the Family Ranidae in China
|School||Nanjing Normal University|
|Keywords||Ranidae Molecular phylogeny Cladistics mtDNA 12S rRNA gene 16S rRNA gene DNA sequence|
The present thesis includes four parts:1 Review: The systematic studies on anuran families, particularly Ranidae were summarized at morphological, chromosomal and nuclear acid levels, and questions in the systematics of the family Ranidae were put forwared.2 Molecular systematics of Chinese ranid frogs: Approximately 850 base pairs of the mitochondrial 12S rRNA and 590 base pairs of the mitochondrial 16S rRNA gene fragments from 31 species of Chinese ranid frogs and 2 species of Chinese bufonid toads were sequenced. Phylogenetic analyses revealed that: ① these frogs are divided into two lineages. The first one contains 8 species belonging to 6 genera, i.e. Euphlyctis limnocharis, Hoplobatrachus rugulosus, Limnonectes fujianensis, Paa boulengeri, P. spinosa, P. robertingeri, Nanorana pleskei, and Altirana parkeri, of which 3 species of Paa group into a monophyletic taxon. The other contains 23 species belonging to 7 genera, of which 5 species of Rana, 5 species of Odorrana, 3 species of Pelophylax, 2 species of Rugosa, and 4 species of Amolops group into monophyletic taxa respectively. These results suggest that Chinese ranid frogs should be classified into two subfamilies, i.e. Dicroglossinae (the first lineage) and Raninae (the second lineage), and they do not support that establishment of subfamily Amolopinae. ② The molecular evidence supports the separation of ranid genera Euphlyctes, Limnonectes, Hoplobatrachus, Paa, Odorrana, Glandirana, Rugosa and Pelophylax from the fomer genus Rana which now including only brown frogs. ③ The relationships among genera of the first lineage revealed by different DNA fragments are mostly identical. The genera Altirana and Nanorana cluster before they cluster with the genus Paa, and a sister relationship between the genera Euphlyctes and Hoplobatrachus is found. The relationships among genera of the second lineage show some differences in the analyses of different DNA fragments. In general, Odorrana is likely to be closely related to Amolops, and a close relationship is also found between Rugosa and Rana, Glandirana and Rugosa. ④ The molecular evidence indicats that the genus Hylarana is not a monophyletic group, a further study on species composition of the genus is necessary. ⑤ The molecular differentiation detected between Lanzhou population and Northeastern population of Rana chensinensis is larger than inter-specific differentiation found in the genus Rana. This indicats that the differentiation between Lanzhou population and Northeastern population of Rana chensinensis is likely to be at species level.