成团泛菌(Pantoea agglomerans)对稻谷的致病性

Pathogenicity of Pantoea agglomerans on rice seeds

分离自稻谷的成团泛菌 (Pantoea agglomerans)菌株的致病性测定结果表明 ,所有成团泛菌菌株对稻谷都有一定的致病力 ,但强弱差异明显 ,其中 FDQ1、FDSN4、XD2、XSH4菌株较强 ,XD2最强 .成团泛菌影响稻谷的灌浆与发育 ,水稻对该菌的易感期为孕穗期到抽穗初期 ,症状表现为抽穗迟、(半 )包穗、白穗、稻粒变色、秕谷率高等 ;该菌还影响稻种的萌发 ,表现为胚芽与胚根的伸长受到抑制 ,容易造成死苗 .成团泛菌对稻谷的污染部位主要集中在内、外颖组织上 .要使该菌保持较强致病力 ,菌液接种菌量应不低于 1 0 8CFU·m L- 1 .

Tests of the pathogenicity of Pantoea agglomerans strains isolated from rice seeds showed that they all could cause rice seeds discoloring, of which FDQ1, FDSN4, XD2, XSH4 were virulent and XD2 was most virulent. P.agglomerans not only influenced the development and maturation of rice seeds, but also inhibited their sprouting. Its staining sites on rice seeds were the inner and outer glume tissue. The concentration of bacterial suspension inoculated was found to be not lower than 10 8 CFU·mL -1 for keeping its strong pathogenicity.