本文报道了桑细菌性疫病病原菌(P.syringae p.v.mori)不同菌株的致病性及其对桑苗不同部位和豆科不同植物致病能力的初步研究结果。结果表明:桑疫病菌不同菌株对桑苗的致病性有明显差异,菌株对桑苗的致病性与其地区来源无明显相关性。但益都菌株(Pm1,Pm5)对豆科植物的致病性显著高于泰安菌株(Pm31,Pm35)。桑疫病菌对桑苗不同部位及对豆科不同种植物的致病性也不同。其对桑苗顶端及上部的致病能力较强;对绿豆、芸豆、菜豆的致病性较强,而对黄豆、黑豆的致病力较弱。 This paper reports the pathogenicity of different strains of P. syringae p.v.mori and their preliminary results on pathogenicity of different parts of S. mongolica and different leguminous plants. The results showed that there were significant differences in the pathogenicity of different strains of mulberry blight on mulberry seedlings. The pathogenicity of mulberry seedlings to mulberry seedlings was not significantly related to their origin. However, the pathogenicity of Yidu strains (Pm1 and Pm5) to leguminous plants was significantly higher than that of Taian strains (Pm31 and Pm35). Mulberry blight bacteria on different parts of the mulberry and legumes of different species of pathogenicity is also different. It has stronger pathogenicity to the top and upper part of mulberry seedling, stronger pathogenicity to mung bean, kidney bean and kidney bean and weaker pathogenicity to soybean and black bean.