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利用青枯雷尔氏菌(Ralstonia solanacearum)无致病力菌株防治番茄青枯病具有很好的应用潜力。作者通过分离筛选自然弱毒株、60Co辐射诱变和EZ-Tn5插入诱变,分别获得3、12和40株青枯雷尔氏菌无致病力突变菌株。经盆栽番茄苗致病性检测,15 d后均未发病,证实均为无致病力青枯雷尔氏菌。进一步对番茄青枯病的防治试验表明,从番茄青枯病发病田块分离的无致病力突变菌株FJAT1458的防治效果最好,防效达100%。该菌株能定殖番茄植株根系土壤、根部和茎部,定殖数量均表现为“先增后减”的趋势,并且接种浓度越大、苗龄越小,定殖数量越大。从构建的防效模型可以看出,不同接种浓度条件下,植株发病率随时间变化符合的回归方程不同,相关系数R值也不同,接种浓度越大,R值越小。本研究获得的青枯雷尔氏菌无致病力突变菌株FJAT1458对番茄青枯病具有很好的防病效果。
The use of virulent strains of Ralstonia solanacearum to control tomato bacterial wilt has good potential for application. By isolating and screening natural attenuated strains, 60Co radiation and EZ-Tn5 insertion mutagenesis, 3, 12 and 40 non-pathogenic mutant strains of R. solanacearum were obtained respectively. The pathogenicity test of potted tomato seedlings showed no pathogenesis after 15 days and proved to be non-pathogenic Ralstonia solanacearum. Further tests on the prevention and control of tomato bacterial wilt showed that the control strain FJAT1458, which is a non-pathogenic mutant isolated from the field of tomato bacterial wilt, has the best control effect with the control effect of 100%. The strain could colonize the roots, roots and stems of tomato plants. The colonization quantity showed a trend of “increasing first and then decreasing”, and the greater the inoculation concentration, the younger the seedling age, the larger the colonization amount. From the constructed model, we can see that under different inoculation concentration, the regression equation that the plant incidence changes with time is different, and the correlation coefficient R value is also different. The greater the inoculation concentration, the smaller the R value. The non-pathogenic mutation strain FJAT1458 obtained from the present study has good anti-disease effect on tomato bacterial wilt.