绿色木霉菌T23对黄瓜枯萎病防治效果及其几种防御酶活性的影响

Biocontrol of Fusarium wilt and induction of defense enzyme activities on cucumber by Trichoderma viride strain T23

本文通过生物测定的方法初步研究了绿色木霉菌T23分生孢子和厚垣孢子对黄瓜枯萎病防治效果及黄瓜幼苗几种防御酶活性的影响。结果表明:黄瓜幼苗经木霉菌处理后,病情指数由33. 69分别降至13. 12和10. 28,经木霉菌处理的黄瓜体内与抗性反应相关的苯丙氨酸解氨酶(PAL)、过氧化物酶(POD)、多酚氧化酶(PPO)及过氧化氢酶(CAT)活性有明显增加,其峰值分别为对照的2. 75、2. 49、2. 42及15. 84倍,说明生物防治过程中可能有木质素、植保素等抗性物质的参与。与分生孢子处理相比,木霉菌厚垣孢子处理的酶活高峰出现得晚,但酶活峰值高。

Biocontrol of Cucumber Fusarium wilt with T. viride T23 was detected through bioassay, and its induction of several defense enzymes in cucumber was examined. Treatments with conidiospores and chlamy- dospores of T. viride T23 on cucumber seedlings reduced the disease index of Fusarium wilt from 33.69 to 13.12 and 10.28, respectively. The activities of defense enzymes, such as phenylalanine ammonia lyase (PAL), peroxidase (POD), polyphenol oxidase (PPO) and catalase(CAT), was measured in roots. Significantly higher levels of these enzymes were detected in T23-treated plants than in control.The maximum peaks of PAL, POD, PPO and CAT activities were enhanced by 2.75,2.49, 2.42 and 15.84 times over control, respectively, indicating that the production of phytoalexin or lignin might be involved in the disease suppression. The enzyme activities in conidiospore-treated cucumber reached their peaks earlier than those in chlamydospores treatment, however, the latter showed higher enzyme activity peaks in cucumber.