Abstract：Abstract Cucumber (Cucumis sativus), a worldwide distributed vegetable, is an economically important?crop in Chongqing. However, viruslike symptoms were observed in greenhouse- and field-grown in the major cucurbit cultivation regions in Chongqing from 2013. In this study, 11 common vegetable viruses specific primers were used to detect the pathogenic agents associated with 5 diseased cucumber plants exhibiting typical stunting, wrinkled, mosaic and distortion symptoms collected from Chongqing. The detection results showed that 5 cucumber plants were mix-infected with more than 4 viruses including Cucumber mosaic virus(CMV), Squash mosaic virus(SqMV), Turnip mosaic virus(TuMV), Watermelon mosaic virus(WMV) and Zucchini yellow mosaic virus(ZYMV). Using PCR, cloning, and sequencing techniques coat protein (CP) gene of WMV (WMV-H3) and ZYMV (ZYMV-H3) were identified for phylogenetic analysis. Compared with reported sequences of different geographic origins, the CP genes of WMV-H3 and ZYMV-H3 shared similarity of 92.3%~96.9%, 93.0%~97.7% at nucleotide level, respectively. WMV-H3 had the highest sequence identity with WMV-T-2-9 and ZYMV-H3 shared the highest sequence identity with ZYMV-Hefei. The phylogenetic trees constructed with CP genes showed that 44 WMV isolates were clustered into 5 groups and WMV-H3 belonged to group Ⅲ, the genetic variation of which was related to geographical distribution and host origins; 80 ZYMV isolates were divided into 6 groups and ZYMV-H3 belonged to groupⅢ, the distribution of which exhibited a distinct geographical differentiation. This is the first report of SqMV, WMV and ZYMV infecting cucumber in Chongqing. The results provide theoretical basis for further study on the distribution of the disease in cucurbit-growing regions and the disease management.
