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Black shank of tobacco (tobacco black shank) of a very wide range of addition to Heilongjiang Province has not yet found the rest of the tobacco planting provinces, including Taiwan, have occurred. Tobacco black shank (Phytophthora parasitica) can harm tobacco, dry smoke, sun-cured tobacco, burley and oriental tobacco cultivation tobacco, extremely damaging. Collected from Chongqing Tobacco Production Regions a typical tobacco black shank samples, back to the laboratory separation, purification and identification. Determine the pathogenic differentiation and physiological races identified strains of tobacco black shank;, and the use of the tobacco area pathogenic strong performance strains composed of mixed bacteria carried on the Chongqing 10 cultivars tobacco varieties Determination of resistance. Expect the precondition and the scientific basis for the directed cultivation of tobacco on the production of disease-resistant varieties and rational distribution. The main results are as follows: 1. Strains collected from July 2005 to October 2006 were collected from Chongqing the Wulong, Wanzhou, Wushan, Pengshui, Fuling, stone pillars, youyang region the tobacco black shank disease samples 123 were purified from tobacco black shank The bacteria strains 52 which Wulong 2 2, Wanzhou, Wushan 7, 12 Pengshui, Fuling 12, nine pillars, Youyang 8. 2. Identification of physiological races randomly selected 40 strains inoculated four differential hosts after 10 days observation, NC1071 40 tested strains manifested as disease resistance, disease index are 0; N. nesophilaI of 40 strains showed resistance to disease, the condition index of 0-20 performance; L8 40 strains were susceptible, disease index 75-100; small gold 1025 performance are susceptible reaction, disease index 77.78-100. TTC solid medium and the liquid medium, the 40 strains were rendering a red reaction. By the identification of host resistance reaction and TTC color reaction can be identified 40 strains are the 1st physiological races. 3. Virulence differentiation of 24 representative strains with swimming the spore suspension IRRIGATING inoculated safflower Hongda MSK326 Yunyan 202 three tobacco varieties, the results showed that the 24 strains in a single tobacco varieties, three The combination of varieties, are obvious pathogenic differentiation between regions. Virulent strain 14 in virulence strains 6, the weak virulence strains 4; MSK326 on performance for the virulent strain in Honghuadajinyuan, 3 virulence strain 11, the weak virulence strains 10; in on Yunyan 202, the performance for two virulent strains, the virulence strains 6, 16 weak virulence strains. 24 strains on a combination of the three varieties, the performance of the virulent strains 2, 16 moderate virulence strains, the weak virulence strains 6. From the of each smoke District strains average disease index of view, tobacco-growing areas of the pathogenic differentiation, the most pathogenic strains of Wulong tobacco-growing areas, the average disease index of 57.41, while the Wanzhou smoke strains pathogenic relatively weak, the average disease index of 18.50. 4. Chongqing cultivars of tobacco black shank resistance selection of 10 varieties of the tobacco area in Chongqing in recent years, the most commonly used in the determination of the present study. Each tobacco area virulence strong performance of the seven strains (FJ2-1, PL3-1, SL1-5, WH1-1, WL1-8, WX1-7 and YL1-2) composed of a mixed bacteria these 10 Varieties of Resistance Determination. The results show that, for the trial of 10 tobacco varieties of tobacco black shank resistant difference Among them, the no high anti varieties; resistant varieties 4, respectively, for the 4th NC82, the Yunyan 201, the Yunyan 203, your smoke; resistant variety two were MSK326, MS Yunyan 85; susceptible varieties 2, respectively, for MS Yunyan87 clouds 202 2; highly susceptible jaw smoke on the 4th Honghuadajinyuan . 5. Culture Collection of four different strains of preservation methods PL2-5, SS1-8, YL1-2 three strains of bacteria save comparison, and saved strains tested on a regular basis to detect. The results showed that distilled water stored at room temperature and liquid paraffin two kinds of methods are better stored at room temperature, suitable for long-term preservation of bacteria; spawn oats slants stored at room temperature, suitable for short-term preservation strains; another oat medium slant 4 ℃ refrigerator Save unsuitable for the preservation of the tobacco black shank.
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