【摘要】 研究了从梨果表面筛选分离到的罗伦隐球酵母(Cryptococcus laurentii)菌株对贮藏柑橘酸腐病菌(Geotrichum citri-aurantii)的抑制作用.实验结果表明:在25℃,病原菌接种量一致的条件下,罗伦隐球酵母的生物防治效果与其接种浓度和其与病原菌接种间隔时间有关.当接种病原菌的量为1×106mL-1时,1×106mL-1拮抗酵母能有效地抑制酸腐病害的发生,拮抗酵母的接种浓度越高,其抑制效果越显著;罗伦隐球酵母同时或先于病原菌接种,可显著抑制酸腐病害的发生.柑橘果实接种罗伦隐球酵母24 h后,多酚氧化酶(PPO)和过氧化物酶(POD)活性升高,整个实验过程中均高于对照.采用不同的处理液处理柑橘果实,发现罗伦隐球酵母悬浮液和培养原液对酸腐病菌有较好的抑制效果,培养滤液和热杀死液也有抑制效果.研究结果表明罗伦隐球酵母菌株对柑橘酸腐病害有很好的防治潜力,其抑制机理可能与营养和空间竞争及分泌抗菌物质有关.更多还原

【Abstract】 Sour rot of citrus fruit could be significantly suppressed by Cryptococcus laurentii.The biocontrol efficacy of C.laurentii was related to the concentrations of the yeast cells and application time.Higher efficacy was achieved when fruits were treated with high concentration of C.laurentii(>1×106 mL-1) and with low concentration of Geotrichum citri-aurantii(1×106 mL-1) at 25 ℃.The efficacy of C.laurentii was consistent when applied at the same time or before the pathogen.The activities of PPO and POD in citrus increased significantly after 24 h of inoculation with C.laurentii.The biocontrol mechanism of C.laurentii was detected by comparing the efficacy of different treatments.The results demonstrated that the disease incidence for the treatments of living cell suspension and washed cell suspension of C.laurentii was significantly lower than that for the culture filtrate and autoclaved cell suspensions.It was suggested that C.laurentii had a great potential to control sour rot of citrus fruit.The biocontrol mechanism might be the competition of nutrition and space,and secretion of antagonistic substances.更多还原