一种生物诱抗剂防治玉米圆斑病效果研究

Preliminary Study on Effect of Maize Round Spot by a Biological Resistance Inducer

利用实验室制备的一种生物诱抗剂(Biological resistance inducer,BRI)成功诱导玉米对圆斑病菌(Cochliobolus carbonum)的抗性,BRI对玉米圆斑病菌孢子萌发及菌丝生长无明显影响。温室接种试验结果表明,BRI浓度在10～100μg/mL范围内,随着BRI浓度提高,其诱导玉米抗圆斑病的效果也相应提高。当BRI处理玉米后1 h再接种玉米圆斑病菌,能诱导玉米产生抗性、减轻病害;随着病菌接种时间的推移,其诱导抗性逐渐加强,控病效果逐渐提高;在接种前5 h喷施BRI,其防病效果达峰值(77.46%);接种前6 h喷施BRI,防病效果缓慢下降。当接种孢子在1×103～5×104个/mL时,BRI防病效果达60.95%～71.46%;当接种孢子达1×105个/mL时,防病效果仅达18.08%。

A home-made biological resistance inducer（BRI） induced caused by Cochliobolus carbonum though it could not inhibit the fungal successfully maize resistance to round spot conidial germination and mycelial growth. BRI induced the resistance and control effect with its concentration ranging from 10 to 100 μg/mL. One hour before inoculation of the pathogen, BRI was sprayed onto maize seedling and could induce the resistance and reduce the dis- ease, and the resistance increased with the delay of pathogen inoculation. BRI controlled 77.46% of the disease when it was applied in 5 hours before the pathogen inoculation and its control effect gradually reduced when that in 6 hours. BRI controlled 60.95% - 71.46% and 18.08% of the disease when the pathogens were inoculated with 1 ×10^3 - 5 ×10^4 spores/mL and 1 ×10^5 spores/mL, respectively.