臭氧对葡萄灰霉病的抑制效果

Effect of Ozone on Controlling Gray Mold in Grapes

研究不同臭氧处理方式对离体及接种在活体葡萄上的灰霉菌的抑制作用,为降低采后葡萄贮藏过程中灰霉病带来的损失提供理论依据。在(20±1)℃条件下用不同剂量的臭氧(0、30、60、90μL/L)对离体灰霉菌分别处理不同时间(5、10、15 min),通过测定菌丝生长长度、孢子形成抑制率、孢子细胞膜完整性及扫描电镜观察来探究臭氧对其抑制效果。用上述4种剂量的臭氧分别对接种了灰霉菌的‘红地球’葡萄处理15 min后(20±1)℃条件下存放5 d。通过测定发病率、病斑直径及相关酶活性来观察臭氧对葡萄灰霉病的控制效果。结果表明:在离体实验中,与对照相比,不同剂量的臭氧对离体灰霉菌处理不同时间后,灰霉菌菌丝的生长均受到了不同程度抑制,随贮藏时间延长抑制效果逐渐减弱;灰霉菌的产孢子率显著下降,部分孢子的细胞膜完整性被破坏,臭氧剂量越高、处理时间越长,效果越好。在接种了灰霉菌的活体实验中,与对照组相比,用60μL/L和90μL/L剂量臭氧处理接种灰霉菌的葡萄果实后,灰霉菌在果实上的生长明显受到抑制;臭氧处理可以使果实丙二醛含量积累减慢,维持较高的抗氧化酶活性。综合分析,臭氧通过抑制灰霉菌菌丝在葡萄果实上的生长和诱导葡萄果实提高抗性来抵抗灰霉菌的侵染,采用90μL/L剂量臭氧处理15 min对离体条件下和接种在‘红地球’葡萄活体上的灰霉菌抑制效果均为最好。

The aim of this study is to provide theoretical support for reducing the loss of grapes caused by Botrytis cinerea during storage.Botrytis cinerea was exposed to ozone at different concentrations(0,30,60and90μL/L)for different times(5,10and15min),and then stored at(20±1)℃.The mycelial diameter,the formation of Botrytis cinerea spores and plasma membrane integrity were analyzed to explore the inhibitory effect of ozone on Botrytis cinerea.In a second experiment,postharvest‘Red Globe’grapes were inoculated with Botrytis cinerea and exposed to four different concentrations of ozone for15min,and then stored at(20±1)℃for5days.The incidence,lesion size and related enzymes activities were measured to evaluate the inhibitory effect of ozone on controlling gray mold in postharvest grapes.The results indicated that compared with the control group,the growth of Botrytis cinerea was inhibited by ozone but the effect decreased gradually over storage time.Ozone could concentration-dependently and time-dependently damage the integrity of the plasma membrane of Botrytis cinerea and reduce conidia germination.On the other hand,the growth of Botrytis cinerea in grapes was strongly inhibited by ozone at concentrations of60and90μL/L.Meanwhile,ozone could inhibit the accumulation of malondialdehyde(MDA)content and help maintain higher levels of antioxidant enzyme activities.Taken together,this study suggested that ozone was effective against gray mold in postharvest‘Red Globe’grapes by inhibiting the growth of the pathogen and inducing host resistance and the best effect was observed at a concentration of90μL/L and15min treatment.