虫害诱导烟草抗性对斜纹夜蛾取食及解毒酶的影响

为探究不同虫害诱导抗性烟草(Nicotiana tabacum L.)对斜纹夜蛾(Spodoptera litura Fabricius)取食和解毒生理的影响,本研究以烤烟品种雄性不育K326为供试材料,观察斜纹夜蛾幼虫对棉铃虫[Helicoverpa armigera(Hübner)]诱导烟草、斜纹夜蛾诱导烟草、烟蚜[Myzus persicae(Sulzer)]诱导烟草的取食选择,以机械处理(打孔、针刺)和未作任何处理的烟草作为阳性和阴性对照,检测分析了取食各虫害处理烟草后斜纹夜蛾体内乙酰胆碱酯酶(AchE)、羧酸酯酶(CarE)、谷胱甘肽-S-转移酶(GST)、多功能氧化酶(MFO)等酶活性的变化。结果表明,斜纹夜蛾初孵幼虫喜食阳性对照打孔和烟蚜诱导处理后的烟叶,而相对避免取食同种昆虫诱导后的烟叶,3龄幼虫亦喜食阳性对照打孔诱导烟叶。取食各虫害处理烟叶后斜纹夜蛾体内的AchE活性均被诱导升高,其中烟蚜处理的AchE活性最高,在48 h时较CK升高了65.17%。棉铃虫、斜纹夜蛾和烟蚜处理在48、48和4 h时分别诱导CarE、MFO、GST活性较CK升高14.38%、72.22%和47.47%,而三种处理对应的MFO和GST,CarE、MFO分别在12和48,48、4 h时升高后与CK没有显著差异(P>0.05),斜纹夜蛾处理的GST活性和烟蚜处理的CarE活性均在48 h时被明显抑制,仅为CK的55.67%和81.05%。说明斜纹夜蛾对不同抗性烟草存在取食差异,取食抗性烟草均可激活斜纹夜蛾AchE活性,不同抗性处理下其他酶活性随着时间呈现特异性变化。本研究可为斜纹夜蛾在烟田中的综合防治研究提供思路和研究基础。

Effects of Herbivore Induced Tobacco Resistance on Feeding and Detoxification Enzymes of Spodoptera litura (Lepidoptera: Noctuidae)

In order to investigate the effects of tobacco with different pest-induced resistance on feeding and detoxification physiology of Spodoptera litura, tobacco male sterility K326 was used in this study to observe the feeding selection of S. litura larvae on tobacco induced by Helicoverpa armigera, S. litura and Myzus persica, mechanical treatments(pricking, needling) and untreated tobacco as positive and negative controls. The detoxifying enzymes activities of the following feeder S. litura containing acetylcholinesterase(AchE), carboxylesterase(CarE), glutathione-S-transferase(GST), multifunctional oxidase(MFO) were detected and analyzed. The results showed that the newly hatched larvae of S. litura preferred to eat the positive contrast leaves induced by mechanical pricks and aphids, while the 3 rd instar larvae preferred the positive contrast(punch) leaves relative the S. litura. The AchE activity of S. litura was induced after feeding tobacco leaves, the AchE in aphid processing was exhibited the maximum increase, which was 65.17% higher than that in CK at 48 h. Compared with CK, the H. armigera, S. litura and aphid treatments induced CarE, MFO, and GST at 48, 48 and 4 h increased 14.38%, 72.22% and 47.47% respectively. The activities of MFO and GST, CarE, MFO increased at 12 h and 48 h, 48 h, 4 h, respectively, and there was no significant difference compared with CK(P> 0.05). GST activity of S. litura and CarE activity of M. persicae were significantly inhibited at 48 h, only 55.67% and 81.05% of CK. This indicated that different resistant tobaccos of S. litura have different feeding rates. Feeding resistant tobaccos could activate the AchE of S. litura. Other enzyme under different resistance treatments showed specific changes over time. This study can provide ideas and research basis for integrated control of S. litura in tobacco fields.