Study On Antagonists And Their Bio-control To Pear Disease During Storage

Pear is one of the main fruits grown in China, which has high nutritional value. However, a number of diseases easily occurred in the course of storage, such as physalospora and brown rot disease which was latent infection and could be cleared in time to stop rotting. But the other major diseases such as black heart disease, rotting disease in fruit base, Green mildew, black disease, brown spot, black spot and so on, could seriously affect the storage time as well as the pome quality, thus greatly reduce the economic value. Therefore, it's very important to know the Pear Diseases and grasp integrated control techniques timely and fully in pear storage. In this paper, pears during storage period were used for study. Pome pathogens during storage were separated based on the analysis of the fruits microbial flora, and the best biocontrol microbes were screened. This paper did some research in biological preservation using zymotic fluid of the best biocontrol microbes. The main results were as follows:1. Three types of Pear rot fungi were attained throμgh the organizational separation and the Koch assumption, which were identified as: Botryosphaeria dothidea, Diaporthe oncostoma and Bionectria ochroleuca with morphological and molecular biology methods. The suspected biocontrol microbes (fungi, bacteria, actinomycetes) were isolated by dilution plate method. The best biocontrol microbes were screened by confrontation culture and were identified as Bacillus amyloliquefaciens with morphological and molecular biology methods.2. The fermentation condition of Bacillus amyloliquefaciens was optimized with orthogonal design test method. It determined the best C source as maltose, and the best N source as the (NH4) 2SO4. The optimum fermentation conditions were: temperature of 25℃, initial pH value of 6, cylinders of 125mL, C source was 2%, N source was 0.3%.3. The results of study on fresh-keeping in pome storage period showed: treatment methods with non-membrane were relatively better than that with membrane. When the concentration diluted to 20 times, the relative control effect would be able to reach 43.76%; when diluted to 10 times, it was 62.51%; when diluted to 5 times, 75%; and the stock solution, 87.51%. In the treatments with membrane, when the concentration diluted to 20 times, the relative control effect was only 17.81%; when diluted to 10 times, reached to 46.4%. When diluted to 5 times. 57.14%. The relative control effect of the stock solution was up to 89.29%.4.Results on chemical and biological measuration showed that: compared with pre-stored, the soluble sμgar in pome basically did not reduce by non-membrane treatment, in which good sμgar content was maintained. The soluble sμgar content showed a decreasing trend after membrane treated, but the difference among these treatments was not significant. The soluble protein content was also declined no matter with membrane or without. However, the law of the reduction was not significant, neither between with and without the membrane, nor among the deferent fermentation concentration.