韭菜和辣椒间作对辣椒疫病的防治效果及其化感机理

为明确韭菜和辣椒间作对辣椒疫病的防治效果及其化感机理,比较了韭菜和辣椒不同行比间作对辣椒疫病的防治效果,测定了韭菜茎、叶挥发物与浸提液对辣椒疫霉菌的抑制作用,并分析了韭菜根系对辣椒疫霉菌游动孢子侵染和传播行为的影响。结果表明,韭菜与辣椒行比为3∶1间作能显著控制辣椒疫病的扩展与传播;2.0 g/皿韭菜茎挥发物及0.15 m L/m L茎浸提液对辣椒疫霉菌菌丝生长的抑制活性可达33.33%和88.75%;辣椒疫霉菌游动孢子对韭菜根系具有明显的趋化活性,且于根围迅速休止并萌发,丧失在土壤中继续寻找寄主的能力,其传播侵染行为受到干扰。研究表明,韭菜和辣椒间作可以有效控制辣椒疫病的扩展蔓延,实现对辣椒疫病的生态防控。

Control effects and allelopathic mechanism of pepper and Chinese chives intercropping on pepper Phytophthora blight

To study the control effect and allelopathic mechanism of pepper and Chinese chives intercropping on pepper Phytophthora blight, the control effect of intercropping pepper and Chinese chives were determined, the inhibitory activities of Chinese chives stem and leaf volatiles and extracts to Phytophthora capsici were tested, and the effect of Chinese chives root on infection and spread of P. capsici zoospores were analyzed. The results showed that intercropping two or three lines of Chinese chives with one line of pepper could significantly control the spread of pepper Phytophthora blight. When the concentration of Chinese chives stem volatiles was 2.0 g/petri and the stem extracts was 0.15 mL/mL, the inhibition rate of mycelium growth reached 33.33% and 88.75%, respectively. The zoospores of P. capsici showed obviously chemotropic activity to Chinese chives root. After reached rhizosphere, zoospores quickly stopped, and then encysted into cystospores to germinate. Thus, zoospores lost their ability to spread in the soil and infect host. Chinese chives intercropped with pepper could effectively control pepper Phytophthora blight.