关键词: 柑橘始叶螨, 叶螨科, 线粒体基因组, 系统发育

Abstract: Eotetranychus kankitus is an agricultural pest mite that damages many crops. Conducting mitochondrial genome analysis can clarify its structural characteristics and the phylogenetic relationships among species in the family of Tetranychidae species. The mitochondrial genome sequences of E. kankitus on pomelo and tea plants were obtained by PCR amplification, sequencing, assembly and annotation. The phylogenetic tree of Tetranychidae was constructed based on 13 protein-coding genes and 2 rRNA gene sequences by maximum likelihood and Bayesian methods. The mitochondrial genomes of E. kankitus on pomelo and tea plants were both in size of 13 032 bp, with GenBank accession numbers OQ955767 and OQ955768, respectively. Both the two mitochondrial genomes included 13 protein coding genes, 2 rRNA genes, 22 tRNA genes and a 40 bp control region, with a consistent gene arrangement. The sequence similarity rate of the two mitochondrial genomes was high, and base composition values of the whole genome and each region were close. E. kankitus on both hosts clustered into one branch in the phylogenetic tree, and the genetic distance between them was 0.068 0, which was much smaller than that between E. kankitus and other mites in Tetranychidae. A close relationship was showed between E. kankitus and Panonychus species in both genetic distance and phylogenetic analysis. According to analyses of mitochondrial genomes, the differentiation degree of E. kankitus on pomelo and tea plants was low, and the risk of transference between the two hosts was high. It is recommended that tea gardens with E. kankitus and surrounding citrus crops should strengthen field monitoring work.

Key words: Eotetranychus kankitus, Tetranychoidae, mitochondrial genome, phylogeny