喜树碱对黄瓜白粉病和霜霉病及水稻纹枯病的抑菌活性

以喜树碱为原药,进行农用杀菌剂的开发与研究。室内盆栽的活体实验研究结果表明：喜树碱对水稻纹枯病Rhizoctonia solani,黄瓜白粉病Sphaerotheca fuliginea,黄瓜霜霉病Pseudoperonospora cubensis均有较高的杀菌活性,半数致死质量浓度和90%致死质量浓度分别为41.964,40.495,27.489mg·L^-1和756.776,247.026,341.818mg·L^-1。同时,黄瓜霜霉病的田间药剂试验结果表明,喜树碱对霜霉病菌有杀菌活性,其半数致死质量浓度和90%致死质量浓度分别为11.221和69.128mg·L^-1,因此,喜树碱可能成为有效的生物源杀菌剂。表2参13

Antifungal activity of camptothecin on Rhizoctonia solani, Sphaerotheca fuliginea and Pseudoperonospora cubensis

Effectiveness of a naturally derived fungicide against Rhizoctonia solani, Sphaerothecafuliginea and Pseudoperonospora cubensis was studied under greenhouse and field condition. In greenhouse, the cucumber （Cucumis sativus） seedlings, inoculated with the three fungi respectively, were planted in pot in the condition of 26 - 28℃, 95% relative humidity, 12-hour photophase and 12-hour scotophase after 16 hours illumination. The seedlings were spraying camptothecin in concentrations of with three replications. In the field, the cucumber seedlings inoculated with P. cubensis were spraying with 5, 10, 20, 40 mg·L^-1 camptothecin, 600 mg·L^-1 flumorph-mancozeb and water （the control） by three replications. The results showed that the product exhibited strong antifungal activity on the three plant pathogens, the ρlc50 and ρlc90 values were 41.964 mg·L^-1, 40.495 mg·L^-1, 27.489 mg·L^-1 and 756.776 mg·L^-1, 247.026 mg·L^-1, 341.818 mg·L^-1 respectively. Field test of camptothecin against P. cubensis also showed that camptothecin had high inhibition effects on the pathogen, and the ρlc50 and ρlc90 values were 11.221 mg·L^-1 and 69.128 mg·L^-1 respectively. Ch, 2 tab. 13 ref.]