The Symbionic Relationship Of Several Psocid Species And Their Endosymbionts

Liposcelis Motschulsky 1852, commonly known as "booklice", belongs to Psocoptera, Liposcelididae. It is an important kind of pest infesting stored products and also has the most important economic significance in Psocoptera. Under the support of the National Natural Science Foundation of China (30471173), the psocids samples were collected in the national scope and reared to establish populations in the laboratory, and the species were identified. The mitochondrial 12S rRNA gene of psocids and the 16S rRNA gene of endosymbionts in several psocids species were amplified and sequenced. The study is for the purpose of providing the basic data of the coevolution relationship about the endosymbiont and its psocid host. Main findings are as follows:Totally 31 psocids samples were collected from the 13 provinces or cities national wide, and these samples were all successfully reared in the laboratory. Based on the species identification, theses samples belong to 9 species, including L. entomophila, L. bostrychophila, L. paeta, L. decolor, L. mendax, L. tricolor, L. yunnaniensis, L. capitisecta and L. badia, respectively. Liposcelis tricolor which was collected from Heze, Shandong and Ningde, Fujian, is a new recorded species in China. Liposcelis capitisecta and L. badia which were collected from the Chengdu, Sichuan, and Zhongxiang, Hubei, respectively, are the new described species.The mitochondrial 12S rRNA gene sequences of 10 geographical populations belonging to 3 species of Liposcelis were amplified by using the specific primer.The sequences length are: L. mendax from Yancheng of Henan 365 bp; L. bostrychophila from Sanming of Fujian, Beibei of Chongqing and Xi'an of Shanxi all 364 bp, from Zhengzhou of Henan and Ningde of Fujian 365 bp; the four geographical populations of L. decolor all 373 bp except the population from Tongliang of Chongqing 374 bp. Based on the sequences, the discrete character methods including Maximum Parsimony method (MP) and Maximum Likelihood method (ML), as well as distance methods including Unweighted pair group method using arithmetic average (UPGMA), Minimum Evolution method (ME) and Neighbor-Joining method (NJ) were employed to build the phylogenetic tree. It is suggested that the phylogenetic tree with the UPGMA and the morphological research result are similar, and it is consistent with the previous other studies through the analysis by using the quoted sequence data.The ratio of TS/TV (transition/transversion) of the mitochondrial 12S rRNA gene sequence of ten psocids populations and the overseas scholar's research indicated from the molecular level that the the longer distance between the same species, the longer heredity distance, the longer divergent age, and the longer inter-species heredity difference.The endosymbionsts were detected in three geographical populations of L. bostrychophila and...