内生细菌和几种诱抗剂对哈密瓜叶片防御酶系活性的影响

Effects of Endophytic Bacteria and Some Elicitors on the Defense Enzymes Activities in Leaves of Hami Melon

比较了内生细菌2302、48、261菌株和诱抗剂水杨酸、壳聚糖中科2号、壳聚糖中科6号对哈密瓜细菌性叶斑病和疫霉病的诱导抗性作用及对哈密瓜叶片中防御酶系POD、PPO、PAL活性的影响。筛选出了具有诱导哈密瓜抗细菌性叶斑病和疫霉病菌复合侵染的内生细菌菌株,其中261菌株的诱抗效果可达78.2%,高于化学诱抗剂,且防病效果较持续稳定。施用水杨酸、壳聚糖中科2号、壳聚糖中科6号亦可诱导哈密瓜的抗病性,以壳聚糖中科2号最为显著,诱抗效果可达74.2%。结果表明:2302、48、261菌株诱导接种和施用水杨酸、壳聚糖中科2号、壳聚糖中科6号处理哈密瓜幼苗,可显著提高叶片中PP0、POD和PAL的活性,并与哈密瓜植株抗病性增加呈正相关。

Authors investigated effects of endophytic bacterial strains 230, 248, 261 isolated from Hami melon plant and chitosan zhongke No. 2 （T2）, No.6 （T6） and salicylic acid （SA） as elicitors on induced resistance against Pseuodomonas syringae pv. melonis, Phytophthora drechsleri and defense enzymes activities in Hami melon foliages. Strain 261 expressed high ability to induce the resistance, with control effect 78.2%, which was higher than that of chemical inducers. The different degree resistance in Hami melon seedlings to P. syringae and P. drechsleri could be induced by spraying seedlings with T2, T6, SA, and the best of the elicitors was T2 with 74.2% effects of induced resistance when its con- centration was 80 μg/ml. The results also showed that activities of PPO, POD and PAL enzymes in Hami melon foliages were excited by inoculation with endophytic bacterial strains 230, 248, 261 and spraying T2, T6, SA, and there was a close relathionship between the enzymes activities and disease resistance.