茉莉酸甲酯诱导巨桉对桉树枝瘿姬小蜂的抗性

为探讨茉莉酸甲酯( MeJA)诱导巨桉幼苗防御反应的生化机制及其对桉树枝瘿姬小蜂的抗性效应,在室内采用喷施不同浓度MeJA处理,测定并分析了MeJA对桉叶苯丙氨酸解氨酶( PAL)、超氧化物歧化酶( SOD)、过氧化物酶( POD)和多酚氧化酶(PPO)4种防御酶活性,以及胰蛋白酶抑制剂(TI)和胰凝乳蛋白酶抑制剂(CI)2种植物蛋白酶抑制剂活性的影响。结果表明,喷施MeJA处理24-148 h后,巨桉幼苗叶片PAL、 SOD、 POD和PPO 四种防御酶和TI、 CI两种蛋白酶抑制剂活性均有不同程度的变化；用1.00 mmol·L-1 MeJA处理后桉树枝瘿姬小蜂种群趋势指数为24.13,防治效果达70.98%。 MeJA处理可诱导巨桉幼苗产生明显的防御反应,相关防御酶活性的变化与MeJA浓度和处理时间有关； MeJA可诱导巨桉幼苗产生抗虫性,对桉树枝瘿姬小蜂繁殖力和种群趋势指数产生影响,具有明显的防治效果。

Effect of exogenous methyl jasmonate on induced resistance of Eucalyptus grandis seedlings against Leptocybe invasa

In order to explicate the effect of exogenous methyl jasmonate ( MeJA ) on activities of related defense enzyme and induced resistance of Eucalyptus grandis seedlings against Leptocybe invasa Fisher et La Salle, effects on the activities of related defense enzymes and protease inhibitors such as phenylalanine ammonialyase (PAL), superoxide dismutase (SOD), peroxidase (POD), polyphemol oxidase (PPO), trypsin inhibitors (TI) and chymotrypsin inhibitors (CI) were analyzed by treating with MeJA at different concentrations. The effects of MeJA on the index of population trend and control effect of L. invasa were also measured. The results showed that after 24-148 h, the activities of PAL, SOD, POD, PPO, TI and CI changed in varying degrees. MeJA at 1.00 mmol·L-1 had obvious control effect of L. invasa with 70.98% and the index of population trend reached 24.13. These results indicated that MeJA induced E. grandis resistance against L. invasa which related to the increased activities of defense enzymes and protease inhibitors caused by MeJA.