Antimicrobial activity of volatiles and extracts of 3 Allium crops to plant pathogenic fungi and oomycetes | 三种葱属作物挥发物和提取液对植物病原真菌和卵菌的抑菌活性

chinois. 采用菌丝生长速率法测定了大蒜、洋葱和葱茎挥发物及提取液对26种主要植物病原真菌和卵菌的抑制活性，以期为利用葱属作物轮作或间作控制病害提供指导。试验结果表明，3种葱属作物挥发物和浸提液具有广谱抗植物病原真菌和卵菌活性，但不同葱属作物对不同种类的病原菌抑菌效果有差异。洋葱和葱茎挥发物和浸提液的抑菌能力比大蒜弱，但对部分疫霉菌、腐霉菌、丝核茵等土传病原菌仍具有与蒜瓣相似的抑菌活性。另外，小麦赤霉病菌、辣椒早疫病菌等部分病原菌对3种葱属作物挥发物和浸提液具有耐性。因此，生产上利用葱属作物轮作或间作防治病害时需要根据不同葱属作物对不同病原菌抑制效果的差异进行合理选择，同时需避免葱属作物长期连作引起病原茵敏感性降低。

anglais. To determine the antifungal spectrum of 3 Alliurn crops for disease control by intercropping and rotation, hyphal growth rate method was used to test the inhibitory activity of volatiles and extracts of A. sativurn, A. cepa and A. fistulosum against 26 plant pathogenic fungi and oomycetes. The results indicated that the volatiles and extracts of the 3 crops showed wide spectrum of antifungal activity. The antifungal activity of A. cepa and A. fistulosum were weaker than that of A. sativum. However, the sensitivity of some isolates of Phytophthora, Pythiurn and Rhizoctonia to A. cepa and A. fistulosum were similar to that of A. sativum. In addition, Gibberella zeae and Alternaria solani showed lower sensitivity to all volatiles and extracts of the 3 Allium crops than other isolates. Thus, Allium crops should be reasonably selected for disease control by rotation and intercropping according to the sensitivity of different isolates to the volatiles and extracts of the 3 Allium crops. Long-term monoculture of the 3 Allium crops should be avoided for reducing the resistance risk of pathogen to the volatiles and extracts of Allium crops.