Abstract: In order to investigate levels of genetic variation and differentiation of grape phylloxera, Daktulosphaira vitifoliae Fitch in China, we sequenced the mitochondrial DNA (mtDNA) gene cytochrome oxidase Ⅰ (COⅠ) of 35 samples from four populations. Of the total analyzed sites, 29 (6.13%) were polymorphic, including 17 (3.59%) parsimony informative and 12 (2.54%) singleton sites. Nucleotide frequencies of A, C, G and T were 34.8%, 15.8%, 10.2%, and 39.2%, respectively. In total, 13 haplotypes were identified in the target region. The most common haplotypes were H3 (HAP-A) shared by 5 samples from SHJ, and H13 (HAP-C) found in 19 samples from SXX, HNH and LNX populations. The SHJ population was unique and shared no haplotypes with the other three populations. Nm ranged from 0.02 to 4.03 and the genetic distance varied from 0.001 to 0.040 between populations. Nm (0.02) was smaller, and the genetic distance (0.039-0.040) larger between SHJ and other three populations. Phylogenetic analysis and haplotype network showed that all haplotypes from SHJ formed one cluster, and the other haplotypes from SXX, HNH and LNX are grouped into another, suggesting that there were at least two introductions of grape phylloxera into China.

Key words: grape phylloxera, mtDNA COⅠ, haplotype, genetic diversity, phylogeny