Intra-population Variation Of DNA Barcodes In Several Common Arthropod

The main factors influencing DNA barcode identification in current studies are the evolution rate of cox1 fragments,regional differences,intracellular symbiotic bacteria Wolbachia,mitochondrial pseudogene-Numts and mitochondrial heteroplasmy.Fifteen common species of arthropods were selected in this study.Each species selected more than five individuals,and each species came from the same population.In order to study the differences of DNA barcodes in the population,and whether DNA barcodes can be used to identify species well,and whether there will be overestimation of biological species due to the false appearance of cryptic species due to too large differences.The following conclusions can be drawn from the study?1.Among the 15 species,the difference of DNA barcode between Tenebrio molitor and Armadillidium vulgare is more than 2%.The maximum genetic distance between species can reach 4.0% and 6.2% respectively,which may affect the accuracy of DNA barcode.These two species account for 13.3% of all species.2.The intra-population differences of T.molitor could exclude the effects of intracellular symbiotic bacteria Wolbachia infection and Numts,but there was no difference between different offspring of the same parent.3.Mitochondrial heterogeneity is responsible for the intra-population differences of A.vulgare.Two haplotypes can be detected in the same individual.At the same time,there is a difference of ~6% between different offspring of the same female parent of the same cockroach beetle.The Sanger sequence obtained by qPCR only came from the higher content of haplotypes,but did not reflect the existence of low frequency haplotypes.4.The other mitochondrial genes of T.molitor also showed different degrees of difference,but the difference of the whole mitochondrial genome was smaller than that of the barcode sequence.