Distribution Survey And Database Construction Of DNA Barcoding Database For Main Pest Rodents In Xilin Gol Steppes

Rodent outbreak is one of the important biological hazards in grassland.It destroys grassland ecology,reduces forage yield,leads to grassland desertification,and spread diseases,by which pest rodents damages economic development and threatens human health.There are a vast expanse of grassland in China,so we should grasp those information,such as diversity,distribution and population density of rodent pests for the scientific management.Accurate species identifications is the first important for rodent pest investigation.However,traditional identification by morphology depends on the experience of researchers,which may lead to mistakes in identification of rodent species for similar morphology or other reasons.It will affect the management decision for pest rodents.Therefore,accurate species identification for local rodent species and efficient methods are very important for pest rodents control.In this study,Rodent outbreak occurrence was investigated in the grassland area of Xilin Gol League by trap method from May to September 2022.The survey area included 11 counties including Abaga Banner,Dongwuzhumuqin Banner,Xiwuzhumuqin Banner,Duolun County,Xianghuang Banner,Zhengxiangbai Banner,Zhenglan Banner,Sonid Right Banner,Sonid Left Banner,Taibus Banner and Xilin Hot City.The investigated habitats included warm meadow-steppe,warm typical-steppe and warm desert-steppe.At the same time,based on the morphological identification results,genomic DNA was extracted,CO I gene fragments were amplified,and combined with the information of Genebank and Barcoding website,a DNA barcode database of main rodent species was constructed.Morphological identification and DNA barcode identification were used to determine the distribution characteristics of the main rodent species in the steppe of Xilin Gol League.The main research contents and conclusions are as follows:1)A total of 341 sample lines were set up in 11 counties,and a total of 40,080 effective clip were placed.1928 rodents were captured,with a total capture rate of 4.81%.More than 10% of ground rodent had Brandt’s Vole,Daurian Ground Squirrel,and Mongolian Gerbil,Steppe Zokor and North China Zokor.These species were defined as the main pest rodent species in the Xilin Gol League grassland,and their distribution was plotted.2)On the whole,Xilin Gol League presents the characteristics of high in the north and low in the south,and low in the east and west.Among them,the capture rate of rodents in XIwuzhumuqin Banner and Sonid Left Banner exceeds 10%,and the density of underground rodents in some areas of Dongwuzhumuqin Banner can reach 40 for each hectare.The analysis of the diversity of rodent communities in each county and grassland types found that the central and southern counties had higher diversity,the eastern county was the lowest,the warm typical-steppe and warm desert-steppe had higher diversity,the population structure is relatively stable,and the warm meadow-steppe had the lowest diversity.3)The captured rodents could be classified into 2 orders,6 families,9 genera and 12 species by morphological identification,among which Rodentia belonged to 5 families,8genera and 11 species,and Rabbitforma to 1 family,1 genus and 1 species.By measuring and analyzing the COI gene sequences of 77 samples from 11 rodent species,most of the similarity is more than 98%,three samples are 96% to 97%,the average genetic distance is below 1.5%,only black line hamster is 2.32%,the average interspecific genetic distance is between 6.54 and 22.05%,the determined sequence and reference sequence of the same species can be clustered into one branch.4)In some ways,DNA barcoding is more accurate than morphological identification.For example,the remains can be accurately identified,a new record of the distribution of the North China Zokor in Xilin Gol League was established,and a possible cryptic species of the Striped Dwarf Hamster was found.At the same time,COI genes of 37 species(88.1%)of rodents in the grassland of Xilin Gol League were collected by self-testing and network,and the DNA barcode database of rodents in Xilin Gol League was initially constructed,which can provide an effective reference for the identification of local grassland rodents.