The Molecular Detection And The Complete Genomic Sequencing Of Tomato Mosaic Virus Of Processing Tomato In Xinjiang

XJ124 isolate was obtained from naturally infected processing tomatoes with symptoms of mosaic and malformation in Xin Jiang. A pair of primers were designed based on ToMV CP gene and a fragment of about 689bp was amplified by RT-PCR. The products of PCR were cloned into PMD18-T and transformed into TOP10. The combined clone was identified by restriction enzyme digesting and the nucleotide sequencing. The results showed that the cloned segment is 689bp and containes one open reading frames (ORF) that is composed of 480bp nucleotides encoding a coat protein gene of 160 amino acids. Comparison of the nucleotide and amino acid sequences of the full length of CP gene of ToMV XJ124 with the corresponding sequences of the part of the ToMV isolates reported showed that the homology are 83.1 %～99.1 % at nucleotide level , and 99.4 %～100 % at amino acid level ,respectively. From the above results, the xj124 isolate was identified as ToMV.Complete nucleotides of XJ124 isolated from processing tomato in Xinjiang Province was cloned and sequenced. XJ124 was compared and analysised with other's complete genomic sequence of Tobamovirus. The complete genomic sequence of ToMV (6,383 nucleotides) on processing tomato of xinjiang was obtained through 5 touchdown PCR, cloning and sequecing, which is the tested ToMV isolated from processing tomato at first in xinjiang. It demonstrated that XJ124 consists of 71 and 206 nucleotides at the 5' and 3' non-translated regions respectively and contains four opening reading frames (ORF), encoding four proteins respectively.The encoding proteins from 5' to 3' in file are 1116 nucleotides(125.67kD,essential for viral replication), 264 nucleotides(28.94kD,cell-to-cell movement),159 nucleotides(17.59Dk,coat protein gene); the ORF2 and ORF3 overlap with 18nucleotides;These properties observed agreed consistently with other known tobamoviruses.The RT- PCR detection technique was established for the causal viruses TMV and ToMV of the tomato mosaic disease of processing tomato in Xinjiang Province. The technique was used to detect the diseased samples collected from main regions-producing processing tomato in Xinjiang Province. The results showed that TMV was detected in all of localities of sampling and accounted for 54.43% among the samples collected;and detected ToMV was accounted for only 13.92%,far lower than TMV accounted in 2006.However ,during 2007, ToMV was detected in all of localities of sampling and accounted for 62.50% which the all sample were mosaic;and detected TMV was accounted for only 20.83%,far lower than TMV accounted. The above results implied that the causal viruses of tomato mosaic disease in Xinjiang Province were mainly including TMV and ToMV, moreover, there was a certain relation between the symptoms of sample and the virus. The symptoms of stripe necrosis were mainly caused byTMV,but the symptoms of mosaic were mainly caused by ToMV.