Study on the Biological Characteristics of the Major Pathogen of the Root-rot Disease of the Processing Tomatoes in Xinjiang

【Objective】To detect the biological characteristics of the major pathogen of the Xinjiang processing potatoes and lay a foundation for further understanding its occurrence condition and control.【Method】Major representative strains were selected from previous identified root-rot disease of processing tomatoes and conventional lab method were used for detection.【Result】 The result showed that the optimal temperature for the growth of tested Pythium,Rrhizocton and Phytophthora was between 20-35℃,the optimal temperature for the growth of the three tested Fusarium was between 20-30℃.These fungi could grow between pH values of 5-11.They grow better between pH value of 6-8.With the increase of pH value,the mycelium growth decrease.The tested Pythium and Phytophthora grow relatively well in PDA and CMA culture medium,while the tested Fusarium grow fast in PSA culture medium.The over-winter test showed that all tested Pythium and Phytophthora over-wintered by way of oospores in the soil while Fusarium overwintered by Clamydo spores and conidiospore.【Conclusion】The major pathogen of the root-rot disease of the processing tomato grew better in neutral soil environment.The tested Pythium,Phytophthora and Rhizocton grow fast between temperature of 25-35℃,while tested Fusarium grown well around 25-30℃.The preliminary test indicated that all major Pythium and Phytophthora overwintered by oospores,while Fusarium overwintered by Clamydo spores and conidiospore.