茉莉酸甲酯诱导桉树对焦枯病的抗性研究

A Study on the Induced Resistance of Eucalyptus against Calonectria pseudoreteaudii by MeJA

为了探究茉莉酸甲酯诱导桉树对焦枯病的抗性,用前期研究的11个桉树主栽种系中的感病种系"巨桉3号"和中抗种系"巨尾桉广9"的组培苗为试验材料,通过0.05,0.1,0.5,1 mmol/L茉莉酸甲酯(MeJA)喷施桉树组培苗3 d的处理,以及用0.1 mmol/L MeJA分别诱导桉树组培苗1、3、5、7、10和15 d后,分别得出接种焦枯病菌组培苗抗病性防御酶应答和抗性的持效性结果:(1)不同抗病性的桉苗叶片超氧化物歧化酶(SOD)和多酚氧化酶(PPO)的活性均比对照提高,且在浓度为0.1 mmol/L时,这2种酶活性都达到最大值。(2)在诱导后的接种叶片的PPO和SOD活性都呈先上升后下降的趋势,且在第5天时酶活性最高。同时,两种处理均显示,诱导后感病种系"巨桉3号"酶活性增幅高于中抗种系"巨尾桉广9"。因此得出结论:感病种系"巨桉3号"诱导效果强于中抗种系"巨尾桉广9"。

In order to explore the resistance of Eucalyptus induced by methyl jasmonic acid aganist Calonectria,the tissue.cultured seedlings of Calonectria resistant cultivar ＂E.grandis 3×E.urohylla guang 9＂ and susceptible cultivar ＂Eucalyptus grandis 3＂ were taken as materials,which were sprayed with 0.05,0.1,0.5,1 mmol/L MeJA for 3 days,and treated with MeJA in the concentration of 0.1 mmol/L for 1,3,5,7,10,15 d.The results were as follows.（1） Three days after spraying MeJA in various concentrations on Eucalyptus seedlings,the superoxide dismutase（SOD） and polyphenol oxidase（PPO） levels in the leaves increased compared to the control group.（2）SOD and PPO levels in C.pseudoreteaudii inoculated leaves increased to a maximum at5 d and then decreased until 15 d.Both treatments produced an increase of enzyme activity in the susceptible clone ＂Eucalyptus grandis 3＂ that was greater than that of the mid-resistant clone ＂E.grandis 3 ×E.urohylla guang 9＂.Conclusion：the inductive effect on ＂Eucalyptus grandis 3＂ was better than that on ＂E.grandis 3×E.urohylla guang ＂.