为明确生物杀菌剂对火龙果采后致病菌的防控作用，通过测定苦参碱、中生菌素、春雷霉素、多抗霉素和井冈霉素5种生物源杀菌剂对火龙果4种致病菌[球黑孢菌（Nigrospora sphaerica）、尖孢镰刀菌（Fusarium oxysporum）、黑附球菌（Epicoccum nigrum）和新暗色柱节孢菌（Neoscytalidium dimidiatum）]的菌丝生长抑制率，室内毒力、菌丝电导率和核酸泄露，并进一步开展碘化丙啶染液（Propidium Iodide, PI）试验以探究生物药剂对致病菌细胞膜的损伤作用。结果表明：生物杀菌剂质量浓度为3.00 g/L时，中生菌素对火龙果黑附球菌菌丝生长抑制率为100%，半最大效应浓度（Concentration for 50% of Maximal Effect，EC50）为0.59 g/L；苦参碱对火龙果尖孢镰刀菌、球黑孢菌和新暗色柱节孢菌菌丝生长抑制率分别为90.93%、84.17%和87.80%，其EC50值分别为0.94、0.71和0.62 g/L。经过PI染色试验表明，5种生物试剂均对火龙果采后致病菌菌丝体细胞膜具有一定损伤作用。中生菌素和苦参碱对火龙果采后致病菌具有较好的抑制作用，可作为火龙果采后致病菌生物防控药剂。该研究可为火龙果采后病害防治及田间生物药剂筛选提供一定理论依据。

To clarify the prevention and control effect of five biofungicides (matrine, zhongshengmycin, kasugamycin, polymyxin, and validamycin) on postharvest pathogenic fungi of dragon fruit (Hylocereus undatus), this study aimed to determine the mycelial growth inhibition, laboratory virulence, mycelial conductivity, and nucleic acid leakage of four postharvest pathogenic fungal strains in dragon fruit (Nigrospora sphaerica, Fusarium oxysporum, Epicoccum nigrum, and Neoscytalidium dimidiatum) after treatment with the five biofungicides. In addition, propidium iodide (PI) staining test was conducted to investigate the damaging effect of biofungicides on the cell membranes of pathogenic fungi. The results showed that the inhibition rate of zhongshengmycin on the mycelial growth of E. nigrum was 100% at 3.00 g/L, and the corresponding concentration for 50% of maximal effect (EC50) was 0.59 g/L. The inhibition rates of Picrasidine on the mycelial growth of F. oxysporum, N. sphaerica, and N. dimidiatum were 90.93, 84.17, and 87.80%, respectively, and the corresponding EC50 values were 0.94, 0.71 and 0.62 g/L, respectively. The PI staining test showed that the five biofungicides damaged the cell membranes of the mycelia of the pathogenic fungi in the postharvest H. undatus. Zhongshengmycin and Picrasidine had good inhibitory effects, making them adequate biofungicides for postharvest pathogenic fungi of dragon fruit. This study provides a theoretical basis for the prevention and control of postharvest diseases of H. undatus and the screening of biofungicides applicable to field production.

国家自然科学基金项目（32160595）；贵州省科技成果应用及产业化计划项目[黔科中引地（2022）4051]；贵州省第六批“千”层次创新型人才项目 [筑科合同-GCC[2022]008]