Detection and seed transmission characteristics of tomato viruses in tomato planting new area of Nujiang,Yunnan
Virus diseases have caused serious harm to tomato production.In recent years,it has occurred seriously in some new tomato planting area,and the source of the viruses were suspected from the tomato seeds.In this study,RNA-seq high-throughput sequencing and RT-PCR were used to detect virus species in diseased tomato samples in the new tomato planting area of Nujiang prefecture,Yunnan province.Furthermore,the diseased tomato fruit seeds were collected for ultrathin section preparation and electron microscopy observation.After seeding of diseased tomato fruit seeds,the seedlings were detected for viruses by RT-PCR.The results showed that the viruses detected by RNA-seq and RT-PCR include tomato zonate spot orthotospovirus(TZSV),tomato yellow mottle-associated virus(TYMaV),chili veinal mottle virus(ChiVMV)and southern tomato virus(STV).The Orthotospovirus virions were observed in the embryo cells of the diseased tomato fruit seeds by transmission electron microscopy(TEM).28 days after the diseased fruit seeds were sown,the viral like symptoms were observed on seedlings.TZSV,ChiVMV and STV were detected on seedling by RT-PCR,and the infection rates were 60%,100%and 80%,respectively.These results provide strong evidence for TZSV transmission by seeds and provide a basis for source prevention and control of tomato virus disease.