Studies On Pathopoiesia Mechanism About Yellow-rotting Of Pleurotus Ostreatus

Pleurtus ostreatus is one of the most important edible fungi species. Its mushroom fruit is delicious in taste and involes abundant nutrition, so it is always very welcome. But yellow-rot disease is one of the main diseases of pleurtus ostreatus and the situation is worse and worse especially to dark-colored species. The disease could result in a dramatic decrease in production even a total failure. Studying on pathopoiesia mechanism of pleurtus ostreatus yellow-rot disease will drive people to provide more effective protections against the disease.First, we isolated two main strains of bacterial from cultivation plate (G1 and G2). We found out the mushroom fruit with G1 was the same as natural infection fruits by resumption infection experiment. So, it is believed that G1 is the main pathogen of yellow-rot disease. We identified this pathogen strain as pseudomonas fluorescence by traditional physiological-biochemical experiment, 16s rDNA analysis and Biolog microbial identification system.Having investigated pathopoiesia mechanism of fungus, we studied pathopoiesia methanism of pseudomonas fluorescence to pleurtus ostreatus yellow-rot disease by many methods such as finding out its influence on the growth rate of pleurtus ostreatus mycelium, the impact to the cell membrane or cell wall and the state of utilizing polyoses. The results indicated that pseudomonas fluorescence damaged the cell wall by decomposing its mainconstituent------chitin and cellulose, and then damaged the cell membrane, thenthe inclusion overflow. More than 70% of the inclusion is polyoses and 50uL pseudomonas fluorescence cultivated for 12hours in beef extract culture medium utilized the polyoses about 2500ug within 48 hours by phenol-sulfuric acid method. The result indicated that pseudomonas fluorescence can utilize over 80% of all the polyoses, then impeded metabolism and accumulation of polyoses seriously, so refrained the growth rate of pleurtus ostreatus fruit.Then, we got samples from the water, the soil, the air and the cottonseed in the cultivating room where we found the strain which is infected with the disease separately. After series of separation and purification, we got thirty-four strains bacteria. We found that pseudomonas fluorescence mainly came from soil and cottonseed by traditional physiological-biochemical experiment and Biolog microbial identification system.In addition, we studied pseudomonas fluorescence's sensitive medicine and their density of bacteriostasis. We also studied impact of some strains that can secrete streptomycin. At last, we summarized the main causes of pleurtus ostreatus yellow-rot disease such as bad environments, insufficient ventilations and nonstandard management and so on. Only if we find out the pathogenicbacteria and understand the pathopoiesia mechanism, we must think of more effective steps of prevention and cure pleurtus ostreatus yellow-rot disease.