Varieties Resistance And Bactericide Screening To Pseudomonas Tolaasii In Pleurostus Ostrestus

At present, bacterial diseases are getting more and more serious, which become one of the main diseases in mushroom production. Blown blotch affects the production of oyster mushroom. More importantly, it debases the quality of the oyster mushroom, which affects the economic benefits of oyster mushroom cultivation and the healthy development of oyster mushroom industry. In order to further clarify the disease and select disease resistant varieties, this experiment collected infectious samples from mushroom cultivation sheds in the suburb of Zhengzhou, Henan. Then pathogenic bacteria were isolated and identified. Blown blotch disease resistance of several species was determined, and pathogen control agents were sifted. This study provided a scientific basis for the guidance of actual production.The strain was isolated from diseased fruiting body of Pleurotus ostreatus, and testified by Koch’s Rule. This pathogen strain was identified as Pseudomonas tolaasii by morphological characterization and16S rDNA analysis. Further experiments found that26℃～28℃was the optimum growth temperature for the bacteria. Pathogenic bacteria incubated for18～24h achieved a stable growth stage, so the proper incubation time of the test bacterial suspension should be20～22h.In order to explore the disease resistance of different varieties and screen for disease resistant varieties, eleven P. ostreatus varieties with sporophore color difference were tested. According to the statistical results, three high sensitive varieties, four middle sensitive varieties, three middle resistant varieties, and one high resistant variety were identified respectively. The results showed that the resistance of the P. ostreatus varieties correlated with the sporophore color and fruiting temperature in some degree. We suggested that resistant varieties such as the Su6, Huaping36could be utilized directly in mushroom farms with high disease incidence after certain pre-tests-New varieties could also be obtained by conventional breeding or molecular tools assisted breeding.A constant broth dilution method was used to filter agents sensitive to Pseudomonas tolaasii. Through the reading of the literature, four kinds of chemicals frequently used in production were chosen:agricultural streptomycin sulfate, dichloroisocyanurate sodium, calcium hypochlorite and chlorine dioxide. MIC values of the four chemicals were as follows:dioxide chlorine8μg/mL, calcium hypochlorite320μg/mL, the other two agents failed to detect dichloroisocyanurate sodium128μg/mL, agricultural streptomycin sulfate1280μg/mL. This result indicated that chlorine dioxide performed the best in resisting pathogens Chlorine dioxide was also recognized internationally as the fourth generation of efficient, safe, broad-spectrum disinfectant. It was recommended to use as the prevention pharmacy against theoyster mushroom Blown blotch disease.