蝉花SLGY-2对斜纹夜蛾生长发育及体内保护酶活性的影响

Effects of Isaria cicadae SLGY-2 on the Development and Protective Enzyme Activities in vivo of Spodoptera litura

为探究蝉花Isaria cicadae SLGY-2对斜纹夜蛾生长发育和体内3种保护酶活性的影响。采用不同浓度的蝉花SLGY-2对斜纹夜蛾2龄幼虫侵染处理,观察后期生长发育;并对不同时间段处理后斜纹夜蛾体内酶活性进行测定。结果表明不同浓度孢子悬浮液处理后,斜纹夜蛾幼虫发育历期显著延长,化蛹率和羽化率显著降低,同时产卵量也显著降低;对蛹重和卵的孵化率无显著影响。孢子悬液浓度在1×108个/mL时,虫体内SOD活性在处理16 h时达到最高,为75.98 U/mg,酶的比活力为同期对照组的2.49倍,CAT活性为88.46 U/mg;处理24 h时,POD活性为7.56 U/mg,3种酶活性的值大于浓度为1×10^7个/mL条件下的处理值,且与同期对照处理结果差异显著。结果表明斜纹夜蛾在抵御蝉花SLGY-2侵染过程时,虫体内3种保护酶均出了应激反应,且随着菌株孢子浓度增加,酶活性逐渐上升,但最终表现为下降。

In order to investigate the effect of Isaria cicadae SLGY-2 on the development of Spodoptera litura and the activities of three protective enzymes.Different concentrations of I.cicadae SLGY-2 were used to infect the 2nd instar larvae of S.litura,and the growth and development in the later period were observed;and the enzyme activity in S.litura was determined after treatment at different time periods.The results showed that the development period of S.litura larvae was significantly prolonged the pupation rate and the emergence rate were significantly reduced,and the egg production was also significantly reduced.There was no significant effect on the pupal weight and the hatchability of eggs.When the spore suspension was 1×108 per milimeter,the SOD activity in the worms reached the highest at 16 h,75.98 U/mg.The specific activity of the enzyme was 2.49 times that of the control group during the same period,and the CAT activity was 88.46 U/mg.POD activity was 7.56 U/mg when treated for 24 h,and the activities of the three enzymes were all greater than the first two concentrations,and the results were significantly different from the control treatments of the same period.During protection against the infestation of I.cicadae SLGY-2,S.litura responded to the three protective enzymes in the insect body,and the enzyme activity gradually increased with the increase of the spore concentration of the strain,but eventually showed a decline.