大黄酚对黄瓜白粉病的生物活性及内吸传导性研究

Research on biological activity and the uptake translocation of chrysophanol against Sphaerotheca fuliginea in cucumber

采用喷雾法研究了大黄酚对黄瓜白粉病的生物活性及其在黄瓜组织中的内吸传导性。结果表明,大黄酚对黄瓜白粉病菌具有较高毒力,感染白粉病的叶片经200 mg/L的大黄酚处理2 d后,霉状物变褐色,病斑枯死。扫描电子显微镜观察显示,黄瓜白粉病菌经大黄酚处理后,菌丝和分生孢子梗扭曲、变形,分生孢子塌陷。盆栽试验表明,利用大黄酚防治黄瓜白粉病具有较长的持效期,黄瓜子叶上喷施100 mg/L的大黄酚,20 d后接种病原菌,其防效仍达84.83%,与有效成分500 mg/L的硫磺悬浮剂防效相近。此外,大黄酚在黄瓜组织中具有一定的跨层传导性,其横向传导性较弱,几乎无向顶及向基的传导性。

The biological activity of chrysophanol on the development of Sphaerotheca fuliginea Poll.and the uptake translocation of chrysophanol in cucumber leaves were determined by spraying method.The results showed that chrysophanol has high toxicity against S.fuliginea,powdery mildew colonies on the infected leaves were brown and dead at 2 days after being treated with 200 mg/L chrysophanol.Morphological investigation by scanning electron microscopy showed that chrysophanol affected fungal survival,caused distortion and malformation of hyphae and conidiophores,and conidia collapsed.The efficacy of chrysophanol in controlling cucumber powdery mildew,remained 84.83% 20 days after foliages spraying with chrysophanol at 100 mg/L on cucumber cotyledons,which was similar to that of 50% sulfur SC at 500 mg/L.Moreover,chrysophanol showed certain cross-layer and little transverse effect in cucumber plants,but no acropetal and basipetal uptake translocation effect.