铅胁迫对舞毒蛾幼虫发育及解毒酶活性的影响

摘要

为探究重金属铅胁迫下林木害虫的发生趋势,依据前期对银中杨(Populus alba 'Berolinensis' L.)叶片中Pb质量分数的研究结果,以Pb质量分数分别为33(低)、43(中)、48(高)mg· kg-1的3种不同饲料,室内饲养舞毒蛾(Lymantria dis par)幼虫,分析Pb胁迫对舞毒蛾幼虫死亡率、化蛹率以及对其3~4龄幼虫体内CarE和GSTs酶活性的影响.结果表明:随着Pb质量分数的增加,舞毒蛾幼虫死亡率增加,化蛹率降低,其中Pb质量分数中、高处理组的死亡率和化蛹率均与对照差异显著(P<0.05).与对照相比,舞毒蛾3、4龄幼虫体内,Pb中质量分数处理组的CarE活性均显著增加(P<0.05),GSTs活性也不同程度的升高;Pb高质量分数处理组的CarE和GSTs活性均不同程度降低,其中4龄幼虫的CarE活性显著低于对照(P<0.05).说明铅胁迫能干扰舞毒蛾解毒代谢和生长发育,不同程度地抑制舞毒蛾的发生.%In order to investigate the occurrence patterns of forest pests under heavy metal(lead)stress, three artificial diets containing different concentrations of Pb(33,43 and 48 mg/kg)were used to rear the gypsy moth larvae for determining their effects on the larval mortality and pupation rate,as well as the activities of detoxification enzymes(CarE and GSTs) in the 3 rd to 4 th instar larvae.With the increase of Pb concentration in the artificial diets,the larval mortalities were in-creased significantly at the higher Pd levels(43/48 mg/kg), whereas,the pupation rates were decreased strongly at the medium and high Pd concentrations(P<0.05).Compared to the control group,CarE activity in the 3 rd-4 th instar larvae in the medium Pb concentration group was significantly higher(P<0.05), and higher GSTs activities were also found at the low and medium Pd levels.In contract,the CarE and GSTs activities at the high Pb concentration were lower than those in control group,with the CarE activity in 4 th instar larvae being significantly lower.Therefore,Pb stress could affect both the detoxification and growth of the gypsy moth,and might inhibit its occurrence to varying degrees.