莱氏野村菌紫外线诱变抗敌敌畏菌株的生理特性

[背景]夜蛾科害虫易对化学杀虫剂产生高抗性,但一些化学农药可以对部分虫生真菌的毒力作用效果起增幅作用,目前缺乏对莱氏野村菌(Nomuraea rileyi)的该方面研究.[目的]探究对常用有机磷杀虫剂敌敌畏具有较强耐药性的紫外线诱变莱氏野村菌突变菌株的生理特性,包括菌丝生长、产孢情况和产几丁质酶活性.[方法]在紫外线诱...

Physiological characteristics of the anti-dichlorvos Nomuraea rileyi strains by UV mutagenized

[Background] Injurious insect (Noctuidae) tend to develop high resistance to chemical pesticides, some of them can increase the effect of some entomogenous fungi. There is a lack of research on Nomuraea rileyi in this part currently. [Objective] To explore the physiological characteristics of UV- mutant Nomuraea rileyi mutants, which are highly resistant to dichlorvos, a common organophosphate insecticide, including mycelial growth, sporulation and the activity of chitin enzyme. [Methods] Based on the mutant strains Nr-UVY1 and Nr-UVY6, which were screened by UV-induced mutagenesis of Nomuraea rileyi, the mycelial growth inhibition rate, the subculture sporulation amount, and the chitinase activity were measured by the addition of different concentrations of dichlorvos growth medium. [Results] On the medium containing 1 291 mg/L dichlorvos, the inhibition rate of dichlorvos on the mycelial growth of the original strain reached 100%, and the mutant Nr-UVY1 (42.38%) and Nr-UVY6 (37.01%) were far away lower than the original strain. According to the mycelial growth inhibition rate curve, when the treatment concentration was higher than 1 291 mg/L, the curves of the two mutant strains increased steadily and were much lower than the original strain, indicating that the resistance of the mutant strains to dichlorvos was remarkable and stable. On the medium with different concentrations of dichlorvos, the mycelial inhibition rate of the mutant strain Nr-UVY6 was smaller than that of the mutant strain Nr-UVY1, manifesting Nr-UVY6 was more resistant to dichlorvos. On the same culture conditions, the initial sporulation time of the two mutant strains was slightly later than the original strain, but the difference was not significant. The sporulation of the mutants was significantly higher than that of the original strains in each generation. In particular, the sporulation of Nr-UVY6 was always more than 2 times higher than the original strain and more stable. The chitinase activity measured by the transparent circle method, the mutant strain Nr-UVY6 was higher than Nr-UVY1 and the starting strain. [Conclusion] The mutant strains subjected to ultraviolet mutagenesis have much higher resistance to dichlorvos than the original strains, and exhibit better traits in growth and reproduction, and it is possible to further explore their level of pathogenicity due to their high activity of chitinase enzyme.