粉拟青霉对菜蚜的致病力研究

Experiment in the Pathogenicity of Isaria farinosa to Lipaphis erysimi

[目的]报道了粉拟青霉(Isaria farinosa)对菜蚜(Lipaphis erysimi)的致病力,为探索对菜蚜的有效生物防治方法提供参考。[方法]用无菌水将粉拟青霉分生孢子从PDA平板上洗出,配制成1.5×108孢子/ml的高浓度孢子悬浮液用于蚜虫感染试验;将配制成的孢子悬浮液按梯度稀释法制成孢子数分别为1.5×104(pf1)、1.5×105(pf2)、1.5×106(pf3)、1.5×107(pf4)、1.5×108(pf5)孢子/ml的5个浓度用于毒力测定。[结果]在用粉拟青霉1.5×108孢子/ml的孢子悬浮液处理7d后,菜蚜的感染率达到92.22%,死亡率为100%,校正死亡率为83.33%。说明粉拟青霉菌株PFCB001对菜蚜易造成侵染,并具有很高的毒力。粉拟青霉对菜蚜的毒力回归方程为:y=0.5957x-3.3240,LC50为3.7990×105孢子/ml,随着孢子浓度升高,蚜虫的死亡率也随之升高,时间越长,菜蚜死亡率越高。[结论]粉拟青霉对菜蚜具有良好的致病性,运用粉拟青霉防治菜蚜具有很大的潜力。

[ Objective] The reference for the effective biological control method of Lipaphis erysimi was provided through the research on the pathogenicity of Isariafarinosa to it. [ Method] The Isariafarinosa conidia washed from a PDA plate with sterile water, which suspension with high concentration of 1.5 × 10^8 spores/ml was prepared for the test of aphid-infected. The test in toxicity to Lipaphis erysimi was conducted with 5 treatments with concentrations of 1.5 × 10^4 （ pf1 ）, 1.5 × 10^5 （ Pf2 ）, 1.5 × 10^6 （ pf3 ）, 1.5 × 10^7 （ Pf4 ） and 1.5 × 10^8 （ Pf5 ） spores/ml. [ Results] The infection rate of aphid reached 92.22% , the mortality rate was 100% and the mortality rate corrected was 83.33% after the treatment of 1.5 × 10^8 spores/ml for 7 days, which indicated the Isaria farinosa strain（ PFCB001 ）was easy to infect the aphid with had high virulence. Paeeilomyces farinosus on the virulence Diaeretiella The regression equation of the pathogenicity of Isariafarinosa to Lipaphis erysimi was ： y = 0. 595 7x - 3. 324 0 and LC50 was 3. 799 0 × 10^5 spores/ml, and with the concentration-increasing the mortality rate of aphid was also increased; the longer the treatment time was, the higher its mortality rate was. [ Conclusion ] The lsariafarinosa had good pathogenicity to Lipaphis erysimi and it had the great potential in control of Lipaphis erysimi.