臭氧对蔬菜土传病原真菌的抑制作用

Inhibition effect of ozone on soil-borne pathogenic fungi of vegetables

探讨臭氧作为土壤熏蒸剂防控蔬菜土传真菌病害的理论依据。研究离体条件下臭氧熏蒸处理对黄瓜枯萎病菌、立枯丝核菌和甘蓝枯萎病菌3种土传病原真菌菌丝生长和孢子萌发的抑制作用。结果表明,臭氧质量浓度为62～72mg/m3处理对3种供试病菌菌丝生长显著抑制,随处理时间延长,抑制率提高,当达到120min时,抑制率均达到了90%以上均显著高于30和60min的处理,并且菌丝量明显减少,菌丝体发生聚集、卷曲、局部膨大,菌丝隔膜消失、原生质体溶解。黄瓜枯萎病菌和甘蓝枯萎病菌的孢子在水琼脂上涂板,臭氧处理质量浓度为40mg/m3,总体表现为病菌孢子涂板后培养时间越短,臭氧处理时间越长,臭氧对病菌孢子的萌发抑制率越高:病菌孢子涂板后立即处理3min,对孢子的萌发抑制率达到100%,而涂板后培养10h,处理1min,对孢子萌发的抑制作用不明显。臭氧质量浓度为40mg/m3处理3min对孢子具有杀灭作用,相同条件下对菌丝生长的抑制作用较小,说明了孢子对臭氧比菌丝敏感。臭氧具有抑制多种土传病原真菌的良好效果,尝试臭氧作为土壤熏蒸剂防治蔬菜生产中土传真菌病害的发生和危害值得进一步探索。

In order to provide a theoretical basis for using ozone as a soil fumigant for the prevention and control of soilborne fungal diseases in vegetable production, the inhibition effect of ozone fumigation on three kinds of soil-borne pathogenic fungi, including Fusarium. oxysporum f. sp. cucumerinum, Rhizoctonia solani, F. oxysporum f. sp. conglutinans and F. verticillioides, was detected by method of mycelium growth rate after the mycelia and spores were treated. The results indicated that the mycelium was significantly inhibited after ozone fumigation treatment at the concentrations ranging from 62 mg/m^3 to 72 mg/m^3 . The inhibition rate increased with the prolongation of treatment time, and reached up to 90% at 120 min for all treatments. Ozone treatment resulted in hyphal length reduction, mycelium gathering, curling, local swelling, and septum disappearing. Furthermore, ozene treatment of 40 mg/m^3 had inhibition effect on the spores germination of F. oxysporum f. sp. cucumerinum, F. oxysporum f. sp. conglutinans and F. verticillioides. The inhibition rate of spore＇s germination increased with the prolongation of treatment time but decreased with spore＇s cultivation time. The inhibition rate reached up to 100% when the ozene treatment was given soon at spores plating. This study showed that the inhibition effect of ozone treatment on three kinds of soil-borne pathogenic fungi was significant. Ozone, as a soil fumigant, has a potential value to be used for controlling soil-borne diseases.