Chinese DNA Family (Diptera) DNA Barcode And Mitochondrial Genome-wide Study

Tachinidae is one of the most species diverse families in Diptera,the latest international taxonomy system record that there are 4 subfamilies,58 tribes,1500 genera,about 8500 valid species of world,and 4 subfamilies,42 tribes,285 genera,1253 species are recorded in China,account for the world genera,species of 19.00%,14.74%.The complexity of morphological diversity and convergence have made it difficult to identify Tachinidae insects and the amount of repetitive identification work is enormous.The anterior 658 bp of standard COI gene is used for quickly species identification in DNA barcoding technology,it's assumed that the intraspeices genetic distance is far less than interspecies,and then delimiting species based on different genetic distances.In this study,143 specimens were extracted DNA and then run PCR experiment to amplify target gene,finally,obtained 74 morphospecies 108 sequences used in analyses.Eight methods(NJ tree,jMOTU,ABGD,TaxonDNA,bPTP,BarcodingR,GMYC,BLOG)were used to study the suitability of DNA barcoding technology used in Tachinidae rapid identification,and to construct a DNA barcoding database of Chinese tachinid flies.The identification results of each DNA barcode identification program are as follows: jMOTU identification success rate is 94.44%;ABGD is 91.67%;in SpeciesIdentifier the algorithm Best Match/Best Close Match/Cluster are 98.03%,94.11%,81.48%;bPTP is 79.63%;in BarcodingR the algorithm Bayesian,fuzzyId and bpNewTraining are 96.55%,86.21%,89.66%;GMYC is 89.81%;BLOG is 73.68%.The results show that the DNA barcode technologies have high identification success rate in Tachinidae,but there still are some problems in identifying fuzzy species,which need a little artificial assisted identification.From the identification results,the best match method in TaxonDNA has the highest success identified rate of 98.03%,and the success identified rate of Bayesian method in BarcodingR is 96.55%.It is recommended that the two kinds softwares are used to analyze and study the Tachinidae molecular species identification,and the former is less difficult to operate.The database was well-characterized to identify the insects of the family of tachinid flies involved in this experiment,which suggests the validity of the database and provides a practical basis for future research.As the first represent record of subfamily Phasiinae of Tachinidae,the whole mitochondrial genome of the Ectophasia rotundiventris(Loew,1858)are sequenced and annotated,and the whole length(excluding the control region)of mitochondrial genome is 14,843 bp,which contains 37 genes.Using NJ and ML method to reconstruct a phylogenetic tree of 7 kinds of mitochondrial whole genome data include Ectophasia rotundiventris and outgroup,as result,in NJ and ML analyses,the outgroups Lucilia sericata and Sarcophaga crassipalpis form a clade diverged from Tachinidae clades.Subfamily Phasiinae is a basal clade to(subfamily Dexiinae + subfamily Exoristinae).The monophyly of family Tachinidae and subfamily Exoristinae was well supported by NJ and ML trees.