大蒜与黄瓜轮作控制黄瓜疫病及其化感作用初探

A preliminary study on the allelopathy and control of cucumber blight by garlic-cucumber rotation

传统农业种植中常将目标作物与化感作物轮作控制土传病害,但对化感作物控病机制研究较少。本文研究了温室大蒜与黄瓜轮作对黄瓜疫病的控制效果,并进一步研究了大蒜组织挥发物和浸提液对甜瓜疫霉Phytophthora melonis及黄瓜种子萌发的影响,以期为利用大蒜与黄瓜轮作控制黄瓜疫病提供理论指导。结果表明,大蒜与黄瓜轮作可以有效降低黄瓜疫病的发生;大蒜不同组织挥发物和浸提液对P.melonis的各生长阶段都表现出显著的抑菌活性,其中蒜瓣的抑菌活性最强,挥发物(紫皮蒜/白皮蒜)在含量0.5 g/皿时对菌丝生长的抑制率均为100%;蒜瓣浸提液(紫皮蒜/白皮蒜)在浓度1.67 mg/mL时对菌丝生长的抑制率分别为32%和45%;在浓度0.25 mg/mL时对游动孢子萌发的抑制率分别为98%和53%。另外,大蒜挥发物和浸提液在低浓度或含量对黄瓜种子的萌发并无显著抑制效果,但在中高浓度或含量会表现出延缓生长的现象。综上所述,大蒜不同组织产生和释放的化合物对P.melonis具有抑制活性,在生产上可以利用大蒜或大蒜秸秆与黄瓜轮作控制黄瓜疫病的发生。

Allelopathic crop rotation is often used to control soil-borne diseases in traditional agricultural planting, but the mechanism of disease control is rarely studied. The effect of garlic-cucumber rotation on controlling cucumber blight was verified by greenhouse rotation experiments. The effects of garlic volatiles and extracts on Phytophthora melonis and germination of cucumber seeds were further studied in order to provide a theoretical guidance for controlling cucumber blight by garlic-cucumber rotation. The results showed that the rotation of garlic and cucumber could effectively reduce the occurrence of cucumber blight. Moreover, the volatiles and extracts of garlic tissues showed significant bacteriostatic activity to P.melonis at all growth stages, in which garlic cloves had the strongest bacteriostatic activity, and the inhibition rates of volatiles(purple-skinned garlic/white-skinned garlic) against mycelial growth were 100% and 100%, respectively at 0.5 g/dish;the inhibition rates of the clove extracts(purple garlic-skinned/white-skinned garlic) against mycelial growth were 32% and 45%, respectively at the concentration of 1.67 mg/mL, and the inhibition rates of extract(purple-skinned garlic/white-skinned garlic) against spore germination were 98% and 53% at 0.25 mg/mL, respectively. In addition, garlic volatiles and extracts at low concentrations did not significantly inhibit the germination of cucumber seeds, but at medium and high concentrations, the growth of cucumber seeds was delayed. In conclusion, compounds produced and released from different tissues of garlic showed inhibitory activity against P.melonis, and garlic or garlic straws rotated with cucumber can be used to control the occurrence of cucumber blight in production.