一株红椒软腐病病原菌的分离鉴定及致病性研究

摘要

A pathogen,HBEU-9,was isolated from the soft rotted samples of sweet peppers in Xiaogan,Hubei.In vitro ,inoculated under the laboratory conditions,it could macerate tissues of sweet peppers.In the field,it infected the peppers with the soft rots.Pathogenicity of HBEU-9 on various vegetables,including green peppers,sweet peppers,lettuce,potatoes,carrots,gourd and cabbages,were examined.The results showed that HBEU-9 was strongly pathogenic toward a wide varieties of vegetables.Based on the morphological characteristics and the 16S rDNA sequence analysis,the pathogen was identified to be Erwinia chrysanthemi (Ech).The antagonism of 7 antibiotics on the pathogen identified gentamicin as the most effective agent among all,even at a relatively low concentration of 60 μg·mL-1 .%从湖北孝感地区红椒软腐病样中筛选分离获得1株软腐病原菌 HBEU-9，在实验室条件下能快速侵染健康红椒组织，并能引起蔬菜田种植的红椒软腐病症发生。进一步对比分析该株病原菌对青椒、莴苣、土豆、萝卜、瓠瓜、白菜的致病性，发现 HBEU-9是一株对常见蔬菜具有广谱致病性及致病能力强的软腐病原菌。对该菌株进行生理生化和分子鉴定，依据病原菌的形态特征，并结合其16S rDNA 序列分析，将病原菌鉴定为菊欧文氏菌（Erwinia chrysanthemi ，Ech）。采用抗生素对该病原菌进行拮抗作用分析，结果表明，相较其他抗生素，庆大霉素即使在较低浓度60μg·mL－1时抗菌效果可达最佳。