紫外线照射对采后苹果抗灰霉病作用的研究

Effect of UV-C irradiation on gray mold of postharvest apples

【目的】研究紫外线照射处理对采后苹果抗灰霉病的作用效果,了解紫外线照射处理诱导灰霉病抗性的机理。【方法】以晚熟苹果品种‘粉红女士’(Malus domestica‘Pink Lady’)为材料,对其进行7.0kJ/m2短波紫外线照射(处理组),以未经紫外线照射的果实为对照组,常温下放置2d后接种灰葡萄孢菌(Botrytis cinerea Pers.),观察灰霉病发生情况,并测定相关生理指标。【结果】随着接种后时间的延长,苹果灰霉病发病率迅速增加,病斑直径不断扩大,对照组果实在接种后2d发病率约为60%,而处理组发病率约为40%,低于对照组;在接种后4d,处理组和对照组发病率均达到100%,到12d果实全部腐烂,病斑直径达到最大。在整个贮藏期内,处理组果实的呼吸速率和乙烯释放速率均低于对照组,处理组果实的苯丙氨酸解氨酶(PAL)、过氧化物酶(POD)、多酚氧化酶(PPO)、β-1,3葡聚糖酶和几丁质酶活性均高于对照组。【结论】紫外线照射可以降低贮藏过程中果实的呼吸速率和乙烯释放速率,诱导果实酶活性增强,对采后‘粉红女士’苹果灰霉病有一定的抑制作用。

【Objective】The study investigated the effects of UV-C treatment on gray mold of postharvest apples.【Method】Apples of Malus domestica ‘Pink Lady＇were inoculated with Botrytis cinerea 2days after treatment with 7.0kJ/m^2 UV-C irradiation,and normal apples without treatment were used as control.Incidence of gray mold was observed and related physiological indicators were measured.【Result】The infection rate increased rapidly and the diameters of lesions extended continuously with the extension of inoculation time.The infection rate of the control 2days after treatment was 60%,higher than that of the treatment group（40%）.After 4days,the infection rates of both groups were 100%,the average diameters of lesions reached the maximum,and all apples decayed after 12 days.Apples in treatment group had lower respiration rate and production rate of ethylene and higher activities of phenylalanine ammonium lyase（PAL）,peroxidase（POD）,polyphenol oxidase（PPO）,β-l,3-glucanase,and chitinase compared to the control group.【Conclusion】UV-C irradiation treatment reduced the respiration rate and production rate of ethylene,increased the fruit enzyme activities,and had certain inhibition against gray mold.