Studies On The DNA Barcoding Of Scarab Beetles Based On The MtDNA CO/Gene

Scarab beetle is one of the major pests of agroforestry production. They have manykinds of and they harm greatly to corps. The larvae is white grub. In order to controlscarab beetles, we have to classify the scarab beetles. The method of morphology iscomplex. With the development of the molecular classification technique, a newmethod was provided to classify the scarab beetles. Mitochondrial cytochrome Coxidase I subunits gene (mtDNA COI) was used mostly and the structure andevolutionary dynamics have been clearly understood. The structure is relativelyconservative and interspecific variation. In the research of phylogeny of closelyrelated species, the structure can provide a wealth of phylogenetic information. DNAbarcoding based on the mtDNA COI gene is simple and efficient.Universal primer (L1490, H2198) and specific primer (Pat, Jerry) were used forcloning mitochondrial cytochrome C oxidase I (COI) gene fragment of four commonscarab beetles. The homologus sequences were compared and obtained panialnucleotide sequence of COI (689bp,775bp)．The genetic distance of these sequenceswere analysed. These sequences were used in three kinds of phylogenetic trees. Theresult shows that the stability of intraspecific distance and differential of interspecificdistance of the sequences amplified with specific primer are obviously higher thansequences amplified with universal primer. The phylogenetic trees which constructedby sequences amplified with specific primer are more consistent with themorphological identification. Sequences amplified with specific primer are moreaccurate to classification scarab beetles.Twenty nine kinds of the main farmland scarab beetles were collected. We used themethod of morphology to classify the scarab beetles first. We take one to three fromevery kind of scarab. Every sample was used for cloning the COI geng. Thesequences were analysied and were used to build the phylogenetic tree. In thephylogenetic tree, we can find the relation of all scarab beetles. And we build a COI geng library of the twenty nine scarab beetles.Holotrichia gebleri Faldermann respectively hybridized with Holotrichiadiomphalia Bates and Holotrichia oblita Faldermann, and obtained the F1. The F2generation were obtained pass the F1generation selfing, It is shows that F1generationof male and female worm has a normal virility. Mitochondrial cytochrome C oxidase I(COI) gene fragment of three scarab beetles were cloned and sequenced. The geneticdistance of these sequences were analysed. These sequences were used in four kindsof phylogenetic trees. The result shows that the genetic distance of three kinds ofscarab beetles is similar, but they are different from the H.parallela Motschulsky. Insummary, The three kinds of scarab beetles are three geographic populations of onespecies.White grubs were collected from farmland of nine place. We used the method ofmorphology to classify the kinds of scarab beetles. The COI gene was cloned fromevery sample. These sequences were compared to the sequences of scarab beetles COIgene. On the basis of genetic distance, the white grubs were indentified. It was agreewith the result of the method of morphology. COI gene can be used to indentify thewhite grubs.