Molecular Phylogenetics Of Subfamily Corydalinae(Megaloptara:Corydalidae)

The subfamily Corydalinae (dobsonflies) belongs to the family Corydalidae of the order Megaloptera. Currently, there are9genera and more than150species of Corydalinae in the world. This subfamily represents the most diversified group of Megaloptera, and has remarkably specialized morphological traits. Some dobsonflies have edible and medicinal value. Reconstruction of the phylogenetic relationships of dobsonflies is crucial for the protection and utilization of their biodiversity and the understanding of the evolutionary history of this group.In this research, the genera Neoneuromus and Protohermes, which are Asian endemic and species-rich groups, were selected as the research objects. Four molecular markers were used for inferring the phylogenetic relationships among species of the two genera, and evolutionary pattern was discussed based on the estimation of divergence time. The main results are listed below:1) The interspecific relationships of Neoneuromus were analyzed based on the DNA sequence data from16S rRNA, COI gene, ND2gene, and28S rRNA D2region, including73samples of8species. Phylogenetic trees were reconstructed with the methods of maximum likelihood, Bayesian inference, and neighbor-joining. The results confirmed the monolyphy of Neonueromus, revealed relationships among species of Neoneuromus, and discovered two cryptic species. The divergence time estimation suggests that Neoneuromus originated in62.46Mya (95%confidence interval was92.30Mya-52.15Mya)2) We chosed136samples of54species in13species-groups of Protohermes to reconstruct the phylogenetic relationships among species-groups based on the DNA sequences of16S rRNA, COI, ND2, with the methods of maximum likelihood and Bayesian inference. The results largely resolved the phylogenetic relationships between species-groups of Protohermes, clarified the genus status of Neurhermes, and revealed the taxonomic status of some species which had not been placed into any species-group.3) Molecular phylogenetics of Protohermes niger and itsclosely related species was analyzed by the gene fragments of mitochondrial16S rRNA and COI. Based on the phylogenetic result and genetic divergence distance, the female of P. niger, which was treated as Protohermes sp. for a long time, was discovered for the first time. Besides, this research revealed the spectacular phenomenon of sexual dimorphism of Corydalinae, which has never been reported.4) We focused on Neoneuromus ignobilis which is a widespread species to study the genetic variation of this species, including71samples from9populations of China and1population of Vietnam, based on the COI sequence data. The results revealed the population genetic structure and genetic diversification of N. ignobilis.