DNA Barcoding Of 106 Species Of Birds In Inner Mongolia

Accurate identification and classification of species is essential to the conservation of biodiversity. The mitochondrial cytochrome c oxidase subunit I (COI) is often used as a fast, simple and accurate molecular tool for the identification of animals, which is called DNA barcoding. The application of this technology is particularly successful in the study of birds. Inner Mongolia Autonomous Region has a vast territory and abundant resources of birds. Up to the present, a total of 467 bird species have been recorded. We amplified the COI gene of 106 bird species (176 individuals) from Inner Mongolia and obtained 176 sequences of DNA barcodes, which belong to 144 haplotypes. The purpose of this study is to investigate the applicability of DNA barcoding in the regional level, such as the effectiveness test of species identification for Inner Mongolia birds and the discussions of DNA taxonomy and phylogeny on the level of lower categories.In the results, the 106 bird species showed a unique DNA barcode. The mean interspecific K2P-distance was 0.54% and the mean intraspecific K2P-distance was 18.11%. The maximum interspecific distance and the minimum intraspecific distance formed an overlapping area(0.15% ～7.78%), making the barcoding gap disappeared. The minimum intraspecific distances of sibling species belong to same genera, on average, about 20 times (7.38%/0.36%) higher than the maximum interspecific distances, which is satisfied the " 10×rule ". These results indicated that DNA barcoding can distinguish most of the sibling species of birds from Inner Mongolia. It can identified about about 90%birds based on the 2.7% threshold of birds and about 98% of the birds based on the NJ tree. The latter analytical approach is more effective than the former for the related species.Through the study of DNA barcoding, we put forward the possibility of the Oriental Skylark (Alauda gulgula) distributed in Inner Mongolia and the supplement of the distributed information in Inner Mongolia about the nominate subspecies of Palla’s Bunting (Emberiza pallasi pallasi). In terms of DNA taxonomy, We found that the Greater Short-toed Lark(Calandrella brachydactyla)had a large interspecific distance with the birds from same genus (10.9%～11.3%), even more than different genera (9.5%～10.5%) from same family. And It can not be clustered as a monophyletic clades with other birds from same genus on the NJ tree. Therefore, we suggested that the Greater Short-toed Lark should be removed from the Calandrella.In conclusion, this research confirmed the effectiveness of DNA barcoding for bird species identification in Inner Mongolia and the important role of discovering hidden groups and the study of DNA taxonomy on the level of lower categories. Not only provided some DNA barcode sequences of birds from different geographical populations, increased the intraspecific variance, but also provided reliable basis of identification for the works of the social basic unitst, such as specimen management, illegal poaching, bird strike aircraft events and so on.