Phylogeny Of Partial Species Of Coreidae Based On Mitochondrial Cytochrome B Gene Sequence

The species of Coreidae are important pests and they do harm to many kinds of plants and fruit trees. So lots of researchers have studied them home and abroad. The present systematics study of Coreidae still stays on the level of morphology. In this study the phylogeny of some species was based on partial nucleotide sequences (about 414bp) of the mitochondrial cytochrome b gene. After analyzing the sequences character by bio-software package,we constructed molecular phylogenetic trees using MP, ML, ME and NJ methods. This study will provide basic data for utilizing and preventing them deeply.In each tree-building method, several distance measures or algorithms were used, but all these distance measures or algorithms produced essentially the same results as follows:1. Cytb exhibits an A/T bias across sites all sites (A+T=69.8%) and it was most produced in the third position (82.8%),which accords with original results.2. Among the nucleotides substitution of Cyib, transition is obviously higher than transversion. Transversion has the bias of A -T and T - A, and always happen in the 3rd position . The high content of A+T in the 3rd position is correlated with the variance of amino acid. Although codon usage is affected by A/T bias, the amino acid composition is not varied with this bias. The obtained sequences coded total 137 AA, in which 57.66% is variable. The most common amino acids and codons are lysine[AAA, asparagines[AAY] and serine[AGR]. The average content of AAA, AAY, AGR is 9.95%, 9.52% and 11.12% respectively.3.This research provided the phyligenetic relations of 4 subfamilies (((Mictinae+Coreidae)+Alydinae)+Phopalinae). The result showed: Phopalinae separates first, Alydinae second from populations Mictinae is related to Coreinae most closely.4.The three tree-building methods provide two common questions: the Acanthocoris Amyot et Serville and Homoeocerus Burmeister belong to Coreinae or not? Homoeocerus Burmeister belongs to Mictinae or not? Many morphologeticcharacters of Coreinae and Mictinae are the same, so the belonging of them needs discussing according to more molecular evidence.5.We examined the mode and temo of evolution of Cytb in Coreidae and the algorithms are essentially the same. Sequence divergences indicate that Cytb is a useful marker at the generic and species level for phylogenetic study,but there is problem at the subfamily level.The present study provided some molecular data for the phylogeny of interspecies and intergenus of partial species of Coreidae in China.