| 【Objective】The study was carried out to determine the pathogen and biological characteristics of coconut fruit rot, and to provide theoretical basis for storage, transportation and disease prevention of coconut fruit.【Method】The pathogenicity of the pure culture from the diseased fruit with dilution-plate method was determined by single spore isolation method, and the pathogen was identified based on morphological and molecular biological methods, and the biological characteristics were studied.【Result】The pathogen causing fruit rot on Cocos nucifera was Thielaviopsis paradoxa, which could infect Artocarpus heterophyllus, Saccharum officinarum, Manihot esculenta, Musa nana, Pachyrhizus erosus, Dracaena angustifolia, Mangifera indica and Ananas comosus. The optimum temperature of mycelia growth, spore production and spore germination of pathogen was 25 ℃ . The optimal pH of mycelia growth was 6, and the optimal pH of spore production and spore germination were 6 and 5, respectively. The best illumination conditions for mycelia growth and spore germination was light culture for 24 h, and the best illumination condition for spore production was dark culture for 24 h. The optimum carbon source for mycelia growth and spore production was gum arabic, while that for spore germination was starch. The optimum nitrogen source for mycelia growth, spore production and spore germination was yeast extract. The optimal media for mycelia growth, spore production and spore germination were PDA, PSA and OMA, respectively. Results of toxicity test of seven fungicides on T. paradoxa showed that Flusilazole·pyrazol had the best inhibitory effect on mycelia growth and spore germination, and EC50 was 0.005 mg/L and 3.657 mg/L, respectively.【Conclusion】Environmental factors have significant effects on mycelia growth, spore production and spore germination of T. paradoxa causing fruit rotten on C. nucifera. The optimal temperature for the occurrence of disease is 25 ℃ . Flusilazole·pyrazol can be used to control coconut fruit rot because of its excellent inhibition on mycelia growth and spore germination. |
