目的分离广藿香青枯病病原菌Ralstonia solanacearum,了解其细菌学性状,并进行致病性测定,为广藿香青枯病的防治提供依据。方法在TZC培养基[蛋白胨10.0 g、酸水解酪蛋白1.0 g、TTC(2,3,5-氯化三苯基四氮唑)0.05 g、葡萄糖10.0 g、H2O 1 L,pH 6.8～7.0]上划线分离培养广藿香青枯菌;通过3糖3醇试验对各菌株的生化型进行划分;采用伤根浸泡接种法对分离所得菌株进行致病性测定。结果经分离纯化,得到在细菌学性状上有明显差异的7个青枯菌菌株。其中HX5、HX7为生化型I;HX1、HX6为生化型II;HX2、HX4为生化型III;HX3为生化型V。致病性试验表明,大部分青枯菌菌株表现较强的致病性,其中以菌株HX4和HX5致病力强且致死率高。结论广藿香青枯病菌存在多个生理小种,在菌体形态、生化分型和致病性等方面均有一定的差异。

To isolate the pathogenic Ralstonia solanacearum from the infected Pogostemon cablin plants and to study the bacteria characteristics, so as to lay a foundation for the control of bacterial wilt. Methods Pathogenic strains of R. solanacearum were isolated from the infected P. cablin plants by being streaked on a tetrazolium chloride (TZC) medium. These strains were used for the classification based on oxidative utilization of three kinds of disaccharide (lactose, maltose, and cellobiose) and three kinds of hexy I alcohol (mannitol, dulcitol, and sorbitol). The pathogenicity was tested by the methods of cutting and soaking roots. Results Seven strains of pathogenic R. solanacearum were isolated from the infected P. cablin plants which contain four biotypes. Strains of HX5 and HX7 belong to biotype I, HX1 and HX6 belong to biotype II, HX2 and HX4 belong to biotype III, and HX3 belongs to biotype V. The result of pathogenicity test indicated that the most strains had strong pathogenicity. HX4 and HX5 have more serious virulence and can cause higher plant death rate. Conclusion Strains of R. solanacearum with different biotypes from the P. cablin plants have different pathogenicity.

国家自然科学基金资助项目(30873376)