Detection By Elisa And Molecular Identification Of Viruses Infecting Processing Tomato In Shihezi

315 Field samples of processing tomato showing necrotic stripe were detected for virus by ELISA using monoclonal antibodies (MAbs)against Tomato mosaic virus(ToMV),Broad bean wilt virus (BBWV) and Cucumber mosaic virus (CMV),respectively. The result showed that the mixed infection of CMV,ToMV and BBWV were causal agent of necrotic stripe disease. On infected plants,the three viruses were positively related by data analyzing using software Eviews 3.0. 21 Processing tomato cultivars were used to determine resistance to the three viruses by ELISA detection, the result showed there existed resistant difference among cultivars,although all tested cultivars were not resistant to three viruses.16 field samples showing yellow mosaic and curl leaf symptoms were collected from processing tomatoes in Shihezi. Fragments of about 500 bp were amplified by PCR from 12 samples with universal primer pair PA/PB for the genus Begomovirs. The PCR product of isolate XJ26-4 was chosen to clone and sequence. The sequence was determined to be 519 nts and shared 98.8% nucleotide sequence identity with DNA-A of Tomato yellow leaf curl China virus (TYLCCNV-Y10,AJ319675). The result showed that 12 field plants were infected by TYLCCNV, from which fragments of about 500 bp were amplified. Based on the determined sequence, the overlapping primer pair PYF and PYR were designed to amplify the entire DNA-A of the isolate XJ26-4. The complete DNA-A sequence of XJ26-4 consisted of 2746 nts, had a genomic organization typical for begomoviruses, and had high sequence identity with isolates of TYLCCNV (91.2～99.5﹪), indicating that XJ26-4 is a isolate of Tomato yellow leaf curl China virus-XJ26-4 (TYLCCNV-XJ26-4)。23 Field samples of processing tomato showing necrotic stripe were chosen to analyze by PCR, which were confirmed to be infected by Broad bean wilt virus(BBWV)by ELISA. Fragments of about 400 bp were amplified using dsRNA from 19 samples with universal primer pair Fab5_R1F and Fab5_R1R for the genus Fabavirus. The PCR products of XJ7-5, XJ7-6, XJ7-9 and XJ14-1 were chosen to clone and sequence. The sequences of XJ7-5, XJ7-6 and XJ7-9 were determined to be 391 nts, 390 nts and 392 nts, respectively. Two clones of XJ14-1 (XJ14-1a and XJ14-1b) were determined to be 390 nts and 354 nts, respectively. The five isolates shared 90.7～98.2% nucleotide sequence identities each other. Similarity search were performed by comparing the five sequences to other sequences in EMBL and GenBank databases. The results showed that the five sequences were partial RNA1 of BBWV2, so it indicates that 19 field plants were infected by BBWV2, from which fragments of about 400 bp were amplified.Based on the determined sequence and accessed genomes RNA1 of BBWV2 in GenBank, 4 the primer pairs in conserved region was designed to further amplify the genome RNA1 sequence of XJ14-1. 3659 and 1765 nucleotide sequence of XJ14-1 were determined and both shared the highest identities with RNA1 of BBWV-[Korea] (AF144234). Based on the accessed genomes RNA2 of BBWV2 in GenBank, the primer pair R2F-1F and R2F-1R in conserved region was designed to amplify the genome RNA2 of XJ14-1. 1300 nucleotide sequence of XJ14-1 was determined and it shared 93.9% identity with RNA2 of (BBWV-[Korea],AF104335).