刺芹侧耳细菌性软腐病病原菌分离鉴定

Identification and Characterization of an Erwinia sp.Causing Bacterial Soft-rot Disease on Pleurotuseryngii Cultivated in China

刺芹侧耳(Pleurotus eryngii)细菌性软腐病,主要侵染子实体,可给生产造成严重损失。本研究从刺芹侧耳主产区福建和河北采集罹病样品,分离到3株病原菌菌株ES4-1、ES1-9和ES1-10,病原菌菌落乳白色,直径约1mm,中间稍隆起,表面光滑,湿润,边缘整齐。革兰氏阴性,菌体短杆状,0.5~1.0μm×1.0~2.0μm,以单生为主,有时成双,无芽孢,无荚膜,兼性厌气,氧化酶阴性。进一步进行16SrDNA序列分析以及gyrB、rpoB、atpD、infB 4个管家基因的多位点序列分析,构建系统发育树。结果表明引起刺芹侧耳细菌性软腐病的病原在分类上属于欧文氏菌属,暂定为Erwinia sp.。

Production of Pleurotus eryngii, one of the most important edible mushrooms widely cultivated in China, has been seriously damaged in recent years by a previously unknown bacterial soft-rot disease that affects both the stipe and pileus of the mushroom. Infected tissues first develop a water-soaked lesion that enlarges rapidly in diameter and depth, and the affected area becomes soft and soggy Bacterial strains ES4-1, ES1-9 and ESI-10 were isolated from infected tissues of fruit bodies sampled from Fujian and Hebei Provinces, and shown to exhibit the general characteristics of the genus Erwinia. Colonies grown on R2A agar（g/L： 0.5 yeast extract,0.25 tryptone, 0.75 peptone, 0.5 starch, 0.3 KHz PO4, 0. 024 MgSO4, 0.3 sodium pyruvate, 15. 0 agar）were circular, slightly convex with entire margins, translucent and non- pigmented. Bacterial cells were short Oram negative rods （0.5~1.0 ~m x 1.0~2.0 t^m） ocurring singly or in pairs, facultatively anaerobic, and oxidase-negative. Phylogenetic analysis based on 16S rDNA and multilocus gene sequence （gyrB, rpoB, atpD and infB） comparisons with other Enterobacteriaceae revealed that the pathogen belonged to the genus Erwinia.