Study On Identification Of Bacterial Disease And Control Of Processing Tomato In Xinjiang

Xinjiang is one of the most suitable areas in China for the growth of processing tomatoes, its yield account for more than 90% of China and 10% of the world. With increasingly expanding of the planting area and the introduction of the seeds frequently and largely,the occurrences of the bacterial diseases of processing tomato has been more and more frequent and severe. It is necessary to investigate the kinds and occurrence of the diseases, which will provide a basis for the management of the diseases.Through The investigation and identification on processing tomato bacterial diseases in Shihezi, Changji, and Bole, The results showed that there are three main kinds of bacterial diseases, including bacterial speck, bacterial spot and bacterial canker, caused by Pseudomonas syringae pv.tomato, Xanthomonas campestris pv vesicatoria and Clavibacter michisganensis subsp.michiganensis respectively. The pathogen of bacteria speck was first disclosed and researched its biological characters. Bacteria speck occurred widely in tomato planting area in Bole. According to the identification of pathogen, the bacteria spot disease occurred widely in tomato planting area in Changji and Shihezi in 2004. However, the bacterial canker did not happen in the north of Xinjiang since the past three years which was very serious in Shihezi. The results of field investigation showed bacterial disease happened heavily in replanted fields in early period. For instance, there was heavy rain in April and May (the transplanting time), the disease would happened badly in seedling. The typical spot symptoms on fruit would decrease the production and merchandise of tomato in the heavy rain of June and July; therefore, the key period for disease control is after rainy season.Quick identification on pathogen was using PCR. 1476bp band was amplified by primer P3(+),P4(-)of bacterial speck. By using primer CMM5,CMM6 for bacterial canker, 614bp fragment was amplified. These PCR tests provided important foundation for pathogen identification and disease diagnoses. Using primer RST65 and RST69 for bacterial spot, expected 420bp band was not amplified. It is necessary for further work on quick detection method for bacterial spot.The resistant assessment of bacterial speck on 18 different cultivars in Xinjiang showed that Hongfan is tolerant, Hongyun and Hongbao is susceptive,the other cultivars are highly susceptive.At the 18 varieties,Hongza 31 and Hongza 34 are tolerant to bacterial spot, Hongyun, Hongbao 3 and Hongjian are susceptive, and the other cultivars are highly susceptive. Through the test of chemical,the two effective chemical drugs for these two bacterial diseases were screened out, which had important guiding on field control.