白灵侧耳水渍状斑点病初探

Preliminary Study on the Wet Blotch Disease of Pleurotus nebrodensis

近几年白灵侧耳(Pleurotus nebrodensis)水渍状斑点病(wet blotch disease)频繁发生,对罹病样品进行显微观察和病原菌分离,并对附生优势菌株进行分子鉴定和致病性研究。结果表明,在水渍状病变组织内未发现和分离到细菌和其它真菌;病斑表面的附生优势菌株L1和F1分别为Pseudomonas sp.和Arthrobacter sp.,回接试验检测无致病性,初步推断该病害不是由细菌或真菌侵染引起的。

In recent years,the incidence of wet blotch of Pleurotus nebrodensis,a disease characterized by water-filled lesions on the mushroom pileus,has increased,causing serious losses to growers.In this study,samples were taken from diseased fruit bodies in greenhouses located in Hebei Province and Tianjin City.Fungal mycelia and bacteria were isolated from the diseased tissue and from the surface of wet blotch lesions,and examined by microscopy.Predominant bacterial strains were identified based on 16S rDNA profiles.No exogenous bacteria or fungi were detected in the diseased tissue,but 75 strains of epiphytic bacteria were isolated from the surface of wet blotch lesions and separated into nineteen groups,L1 and F1-F18.L1 contained 15 strains having 16S rDNA sequences 99.0% similar to Pseudomonas gessardii,and F1 contained 15 strains having 16S rDNA sequences 99.9% similar to Arthrobacter polychromogenes.However,none of these or the other predominant strains were shown to be the etiologic agent of wet blotch disease.Our preliminarily data indicated that wet blotch disease of P.nebrodensis may be not be caused by fungal or bacterial pathogens.