Identification of Hudilong Origins by COⅠ Barcoding and Characteristic Sequence
Objective:To supplement the genetic information for intraspecific and interspecific identification of Hudilong using COⅠ barcoding,and extract characteristic sequences to assist in identification,thereby improving the accuracy of COⅠ barcoding in identifying the origins of Hudilong.Methods:Samples of Hudilong from different regions and other varieties of earthworms were collected.Identification sequences were obtained using COⅠ barcoding,and phylogenetic tree analysis was conducted using MEGA 7.0 software.The intraspecific and interspecific genetic distances of each variety were calculated,and characteristic sequences were extracted from the three origins of Hudilong.Results:The genetic distance between Pheretima vulgaris and P.guillelmi was 0.074,while the genetic distances between these two species and P.pectinifera were 0.187 and 0.194,respectively.After screening and organizing the data,a total of 271 sequences from 22 species of earthworms were obtained,including 218 sequences from newly sequenced samples and 53 reference sequences downloaded from GenBank.The phylogenetic tree results showed that different earthworm species clustered separately at the family and species levels,but at the genus level,the genera Metaphire and Amynthas within the family Megascolecidae were not well differentiated.Two characteristic sequences were extracted from P.vulgaris,and one characteristic sequence each was extracted from P.guillelmi and P.pectinifera.Conclusions:COⅠ barcoding can differentiate Hudilong from other earthworms,and characteristic sequences can help improve the efficiency and accuracy of identifying the origins of Hudilong.