Abstract:

In order to explore virus species in aphids,Aphis craccivora natural populations from Jiangsu were collected and identified,and then the fragmented mRNA from aphid total RNA was used as template to construct the sequencing library.The virus species in A.craccivora were analyzed by virome sequencing technology,and the two novel viruses were further identified.The results showed that after splicing,alignment and classification annotation of sequencing data,177 viral contigs were finally obtained,which were consistent or highly homologous with the sequences of 24 viruses,including 5 plant viruses(involving 5 families)and 19 insect viruses(involving 9 families and 6 unclassified viruses).The virus with the highest sequencing abundance among plant viruses was detected,and after Blast,these viruses with higher homology were all from Cytorhabdovirus,and they had the same conserved domain,so it was considered as a novel Cytorhabdovirus,temporarily named Aphis craccivora associated rhabdovirus(AcARV).The phylogenetic analysis based on viral L proteins revealed that AcARV and Rice stripe mosaic virus(RSMV)clustered into the closest clade,indicating that the two viruses were the closest in evolution.Most identified insect virus species were rarely reported in aphids.Capsid protein VP1 of insect virus Himetobi P virus(HiPV)was detected in A.craccivora via RT-PCR and Western Blot,which confirmed the infection of HiPV in A.craccivora,and it was the first report that HiPV was found in aphids.HiPV VP1 gene of A.craccivora isolate shared 95.5%,99.0% nucleotide identities with Japan and Jiangsu Laodelphax striatellus isolates.These results clarify A.craccivora bears a variety of plant viruses,including a new rhabdovirus AcARV.Meanwhile,insect virus species are abundant in A.craccivora,and HiPV can infect aphids.

Key words: Aphis craccivora, Virus species, Virome sequencing, Cytorhabdovirus, Himetobi P virus