摘要
The phytophagous miteTetranychus truncatusis a serious pest in East Asiabut has a relatively narrower host range than the pest miteTetranychus urticae,which canfeed on over 1200 plant species.Here,we generated a high-quality chromosomal levelgenome ofT.truncatusand compared it with that ofT.urticae,with an emphasis on thegenes related to detoxification and chemoreception,to explore the genomic basis under-lying the evolution of host range.We also conducted population genetics analyses(in 86females from 10 populations)and host transfer experiments(in 4 populations)to investi-gate transcription changes following transfer to a low-quality host(Solanum melongena,eggplant),and we established possible connections between fitness on eggplant and genesrelated to detoxification and chemoreception.We found thatT.truncatushas fewer genesrelated to detoxification,transport,and chemoreception thanT.urticae,with a particularlystrong reduction in gustatory receptor(GR)genes.We also found widespread transcrip-tional variation amongT.truncatuspopulations,which varied in fitness on eggplant.Wecharacterized selection on detoxification-related genes throughωvalues and found a nega-tive correlation between expression levels andωvalues.Based on the transcription results,as well as the fitness and genetic differences among populations,we identified genes po-tentially involved in adaptation to eggplant inT.truncatus.Our work provides a genomicresource for this pest mite and new insights into mechanisms underlying the adaptation ofherbivorous mites to host plants.
基金
supported by a grant-in-aid for Scientific Research(32020103011,U2003112,32202290,32161143014)from the National Natural Science Foun-dation of China.We thank Jia-Huan Guan and Qi-Qi Hufor their assistance in collecting biological materials.