Study On The Molecular Mechanism Of Host Adaption Of Tetranychus Urticae And Teteanychus Pueraricola

Spider mite is a kind of plant-eating pest mite with a wide range of hosts,which belongs to the Arthropoda.The common species include Tetranychus urticae Koch,T.truncatus Ehara,and T.pueraricola Ehara&Gotoh.The widespread host causes great harm to the agricultural production,which is the main pest in the agricultural production.Different insects have different host ranges and feeding preferences,which can reduce ecological pressure while expanding the population,and spider mites are no exception.Although there are a wide range of plant types that the mite can feed on,the behavior of different mite populations varies among all potential hosts.Previous studies have shown that local adaptation caused by intra-population variation is the most important way for mite to expand the host range,and the external manifestations of such intra-population variation are the phenotypic differences within the population,such as body size,reproductive capacity,and behavior pattern.When adapting to the new host,high spawning volume and high mortality of young mites are also one of the coping mechanisms of spider mites.Previous studies on the mite mainly focused on morphology and biology,but there was little research on the molecular genetic mechanism of adaptation of the mite to host plants.In this study,host transfer experiments were carried out to study the adaptability of the two mites to the new host,and the transcriptional regulation mechanism of their adaptation to the new host was studied with the help of high-throughput sequencing technology.In addition,the acaricidal activities of the main acaricides on the market were compared.The main research results are as follows:(1)ecological results after the transfer of host:the ecological indicators(survival rate,spawning capacity and hatching rate of eggs)of the two species of mites after the transfer of host showed different degrees of decline.The survival rate and the number of eggs laid of T.urticae were significantly higher than T.pueraricola on the two hosts,and the hatching rate was lower than that T.pueraricola,but the difference was not significant.In general,the adaptability of the mite was stronger than that of the mite.Through the comparison of the two hosts,it was found that eggplant was more suitable for the survival of the two kinds of mite than tomato,and had less effect on spider mite.(2)transcriptome analysis results:by analyzing the sequencing results of the transcriptome of T.urticae,553 genes were transferred to tomato,with 339 genes up-regulated and 214 genes down-regulated.There were 1020 different genes transferred to eggplant,629 up-regulated genes and 391 down-regulated genes.The sequencing results of the transcriptome of T.pueraricola were analyzed.There were 1063 differentially expressed genes in the transcriptome transferred to tomato,with 497 genes up-regulated and 666 genes down-regulated.There were 340 different genes after transfer to eggplant,among which 116 were up-regulated and 214 were down-regulated.Through cluster analysis,GO functional analysis and pathway-function analysis of the differentially expressed genes,the differentially expressed gene-related metabolic pathways of the two spider mites species were mainly focused on metabolism and catalytic reaction,indicating that spider mite could quickly adapt to the new host through rapid regulation of molecular mechanism after transfer.At the same time,these transcriptome data laid a foundation for the research on the molecular level regulation mechanism of mite and provided data support.