Pepper Mild Mottle Virus Molecular Detection And Analysis Of Characteristics Of Genome In Qinghai、Jiangsu

Capsicum frutescens L is an important vegetable crop which is cultivated over 1.33 x 106 hm2 in China. As a member of Tobamovirus, pepper mild mottle virus(PMMoV) was mentioned in more and more reports in recent years and became the predominant pepper virus in some areas threating local pepper production. While there were no reports about PMMoV in Qinghai and Jiangsu. An investigation on pepper virus was carried out in these two province and samples with leaf crumple symptom was collected and detected using RT-PCR method. PMMoV was detected in these samples and the whole genome of PMMoV from Qinghai province and Jiangsu province was cloned and sequenced. Based on the whole sequence, phylogenetic relation of the two isolates with other members of Tobamovirus and other isolate of PMMoV was analyzed and genomic organization and the taxonomic status of the two isolates was determined. To our knowledge, this is the first report of PMMoV in Qinghai and Jiangsu province. These research will be helpful for the further study on the mechanism of pathogenicity and new stagey for PMMoV management.The following is the main conclusions of our research.Pepper virus disease with leaf crumple and mottle symptoms was found in Qinghai Province and Jiangsu province during our investigation. The incidence of the disease in most greenhouses is between 5% and 20%, while in some greenhouses, the incidence is over 60%. Dwarf symptom caused by early infection was observed in some greenhouse and pepper fruit with mottle symptoms was also observed sometimes, which caused great losses.PMMoV was detected from the samples collected in Qinghai(88%) and Jiangsu(87.5%) province and confirmed by sequencing.The whole genome of PMMoV from Qinghai(PMMoV-Qh-10-8-5) and Jiangsu(PMMoV-Js-6-15-2) was cloned and sequenced, which was comprised by 6356 nt and contained four open reading frame(ORF). ORF1(70-3 423 nt) encodes 127 K RNA-dependent RNA polymerase(RdRp) of 1117 amino acids with a molecular weight of 126 KDa.ORF2(70-4 908 nt) encodes 183 K RdRp of 1613 amino acids with a molecular weight of 183 KDa. ORF3(4 909-5 682 nt) encodes movement protein of 257 amino acids with a molecular weight of 28 KDa. ORF4(5 685-6 350 nt) encodes coat protein of 157 amino acids with a molecular weight of 17 KDa.Phylogenetic analysis revealed PMMoV-Qh-10-8-5 and PMMoV-Js-10-8-5 clustered into PMMoV and belong to cluster III, same with isolates from Japan(C-1421, J, TPo-2-19, Pa18), Spain(S), Brazil(BR-DF01), India(HP1) and China(CN).PMMoV-Qh-10-8-5 and PMMoV-Js-6-15-2 belonged to P1,2...