Study On Identification Method Of Tobacco Wildfire And

Wildfire disease(Pseudomonas syringae pv.tabaci) and angular leaf spot disease(Pseudomonas syringae pv.angulata) is infested with the two main types of bacterial diseases of tobacco alternately. In order to guide tobacco farmers rapid and accurate identification and efficient disease control, based on the polymerase chain reaction(PCR) principle, the testing methods for the pathogens of tobacco wildfire and angular leaf spot was established in this study. 1. The establishment of tobacco wildfire and angular spot disease molecular identification methodPCR primers were designed according to the related gene sequence of wildfire and angular leaf spot strains in NCBI genebank. The pathogen strains of tobacco wildfire and angular leaf spot were amplificated. PCR products were sequenced and compared to find the specific sequence between the pathogens. 2 pair specific primer for PCR identification of wildfire and angular leaf spot of pathogenic bacteria alternately were screened and the molecular identification method of tobacco wildfire and angular leaf spot disease was established.2. The confirmation of the molecular identification method for wildfire and angular leaf spotWith specific PCR screening and tobacco plant inoculation for the 16 suspected wildfire and 20 suspected angular leaf spot isolates, the results showed that eight wildfire and seven angular leaf spot isolates, which PCR screening for positive results, can infect the tobacco plant and express the corresponding symptom. And the isolates from different resources such as tomato soil, soybean rhizosphere and philosopher and pool water which PCR identification were negative cannot infect tobacco plant. The result of PCR screening is concordant with tobacco inoculation results. It is show that molecular identification method is effective and reliable.3. The establishment of a rapid detection method for wildfire and angular leaf spotThrough the PCR amplification to the lesions grinding fluid directly, and optimizing design of multiple PCR system, in which screening two kinds of pathogens in the same reaction, the rapid identification method for tobacco wildfire and angular leaf spot pathogen was set up.4. Purification methods for tobacco wildfire and angular leaf spot pathogen was establishedUsing the specific PCR primers(TABB1F/TABB1 R, 2F2/2R2), PCR screening was carried out on the separation and multi-generational propagate of pathogen colonies, finally ensure miscellaneous bacterium, is not included in pathogenic bacteria.5. The Identification methods of angular leaf spot physiological strain was set upThrough the identification of 19 angular leaf spot inoculated 36 tobacco varieties, The 19 isolates of angular leaf spot can be preliminary divided into five physiological strain I, II, III, IV and V.