| Tomato viral disease often leads to the yield and quality loses of tomato crops. Cucumber mosaic virus (CMV) and Tomato mosaic virus (ToMV) have been considered as the main viruses on tomatoes in China and all over the world. Single or mixed infections of the two above viruses are often found. And virus species, region and climate are relevant to the occurrence of viral disease. In this study, tomato leaves with symptoms were collected in summer and autumn in Eastern China especially Shanghai and Hangzhou. A series of methods were used to detect and differentiate viruses including host diversity, multiplex RT-PCR, restriction enzyme analysis, SPAT, homology comparison and phylogenetic tree analysis.The field tomato leaf tissues with symptoms distiguished into four groups, including severe mosaic, linear, mild mosaic and curling were collected. CMV, TMV, ToMV, TAV, PVX, PVY, ToRSV and TSWV were detected using corresponding ELISA kits. Using 18S rRNA as an internal control, a multiplexed RT-PCR protocol was used for simultaneous detection and discrimination of CMV subgroupâ… , CMV subgroupâ…¡and CMV-sat RNA, as well as TMV and ToMV. The results showed that CMV and ToMV were the most viruses infected tomatoes in Eastern China. In addition both single and mixed infections as well as sat RNA parasitized in CMV subgroupâ… were found using multiplex RT-PCR. Multiplex RT-PCR was proved more accurate and sensitive when compared with DAS-ELISA.A method combined RT-PCR and restriction enzyme analysis was used to classify all three genomic RNAs of CMV and detect reassortant. Six isolates of CMV were selected according to multiplex RT-PCR results as well as symptoms expressed on Nicotiana tabacum and hezuo 903 tomatoes. The results showed that for RNA1 and RNA2, five samples shared the same pattern with CMV subgroupâ… , and for RNA3, sc3, sc7 and xs15 produced the same restriction pattern with CMVâ… B, whereas xs11 demonstrate the pattern of CMVâ… A, but sc20 had no Mspâ… site. It was presumed that the site of Mspâ… on CP gene of sc20 was different from others. Three genomic RNAs of xs16 all accorded with CMVâ…¡. No reassortant were found out in above six samples.Single primer amplification technique (SPAT) was used for complete sequence analysis by extract dsRNAs from the six samples at 14dpi. Sequence of 3a, CP and complete RNA3 of six samples were all compared with Fny (CMVâ… A), Sd (CMVâ… B) and Q (CMVâ…¡). The results demonstrated that RNA3 sequences of five strians of CMVâ… were more closely related to Fny and Sd than to Q while that of one strain of one CMVâ…¡was opposite. Analysis of enzyme site on RNA3 showed that a point mutation happened on Mspâ… site of sc20.In conclusion, CMV and ToMV were found to be the principal viruses infected tomato crops in Eastern China. Both single and mixed infections were all found by multiplex RT-PCR in the study. CMV was found to more commonly distribute than ToMV, and CMVâ… was predominant. CMVâ… B was more prevail than CMVâ… A, and CMVâ…¡showed potential rise in Eastern China. No reassortant was found in our work, it is possible that mass of samples were not many enough or the reassortant has low frequency.
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