| Fruit soft rot disease of Ziziphus jujuba was a new disease which had widely distributed and caused great damage in Xin zheng, Henan Province since 2005. It affected the normal growth of fruit and reduced the commercial value. Furthermore, all the infected fruits were not edible at all. To reduce the loss caused by soft rot disease of Ziziphus jujuba, the pathogen was isolated and identified. Several kinds of fungicides and antagonistic bacteria were also screened in this study. The main results were summarized as follows:1 The occurrence, symptom characteristics and pathogen identification of soft rot disease of Ziziphus jujuba were studied, which widely occurred in xinzheng jujube areas of Henan province. Pathogens were identified by traditional morphological characteristics and ribosome DNA-ITS sequence analysis. The results showed that the villous aerial mycelium was white in the early germination, turned gray after 5 ~ 6 d and black after two weeks, which grew luxuriantly; Pycnidium was flask-shaped, 196.9×213.3μm; Conidium was spindle and colorless with a single spore, 15~20×4.5~6.5μm; Conidiophore was fastigiate. The homology of ribosome DNA-ITS sequence between strain NXK and Botryosphaeria dothidea reached to 99.87 %, with only 2 bp difference, and the pathogen of soft rot disease of Ziziphus jujuba was identified as B. dothidea.2 To promote the sporulation speed and quantity of B. dothidea, some facilitative methods were used in this research. The results showed that B. dothidea had the fastest and largest amount of conidia on the CMA sporulation medium, and the optimum temperature was at 25℃.3 The bacteriostatic effects of 14 fungicides were observed using the growth rate method. The fungicides which have good inhibitory effect were diluted by gradient dilution for carrying out the inhibitory experiments on the growth of mycelium. Toxicity index and EC50 were calculated by POLO software. The results showed that the inhibitory effects of anthrax fukumi, carbendazim and mancozeb were the best,and the correlation between the three fungicides and others was significant. The rate of the three bacteriostasis was more than 99%, and EC50 were 6.633 mg/L, 0.326 mg/L and 27.978 mg/L, respectivly.4 Screening of 10 fungicides whose inhibition rate was up to 90% by spore germination method was conducted and 2 effective fungicides were obtained. Toxicity of the 2 fungicides was tested by gradient dilution. The toxicity index and EC50 was calculated with POLO software. The results showed that the inhibitory effect of 25% sterilization Tong WP, 25% Prochloraz EC were the best,and the correlation between the three fungicides and others were significant. The inhibition rates of the three bacteriostasis were 100%, and EC50 were 15.305 mg/L, and 50.158 mg/L, respectively.5 The results of field test showed that 5 kinds of self-prescription pharmaceutical compound had a certain effect on soft rot disease of Ziziphus jujuba, which had reached a very significant difference compared with the control. The incidence rate of soft rot disease of Ziziphus jujuba treated by the 3rd formula was 35.5%, the lowest one which reached a significant difference compared with other treatments. Followed by the 3rd formula was the 4th, whose incidence rate was 44.5%, and the rest were less effective with incidence rate at about 70%.6 The antagonistic microbes were selected by plates assay, using B. dothidea as an indicator strain. The results indicated that the antagonistic strain CN124, belonging to Streptomyces rimosus, had the best biocontrol effect, and the bacteriostasis rate reached to 97.52%. The fermentation medium of the highest rates of S.rimosus CN124 for B. dothidea was selected using single-factor test combined with the evenness test through the regression analysis. The results showed that the components of optimum medium was starch 11.67%, corn flour 2.69%, (NH4)2SO4 0.22%, CaCO3 0%, and NaCl 0.03%.
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