This study aimed to test the antifungal activity of Trichoderma species against gummy stem blight caused by Stagonosporopsis cucurbitacearum in muskmelon plants. Eight isolates of Trichoderma were screened for their inhibitory effect on S. cucurbitacearum, on potato dextrose agar (PDA) by dual culture assay and pre-colonized methods. The results show that Trichoderma sp. PSU-P1 was superior in inhibiting the fungal growth of S. cucurbitacearum. Molecular identification of internal transcribed spacers (ITS), RNA polymerase II (rpb2), and translation elongation factor 1-α (tef1-α) gene sequences revealed the isolate PSU-P1 as Trichoderma asperelloides. To clarify the defense response, enzyme assays of the defense-related enzymes peroxidase (POD) and polyphenol oxidase (PPO) and the cell wall degrading enzymes chitinase and β-1,3-glucanase were conducted for muskmelon seedlings inoculated with T. asperelloides PSU-P1. The results show that the activities of POD, PPO, chitinase and β-1,3-glucanase were higher than in the control. Crude metabolites extracted from T. asperelloides PSU-P1 inoculated muskmelon plants caused abnormal fungal morphology. The inoculation test (in vivo) revealed that muskmelon seedlings treated with T. asperelloides PSU-P1 showed resistance to gummy stem blight with a disease score of 0.2 and disease severity index (DSI) of 10%, lower than those of the control, which had a disease score of 2.8 and 75% DSI. The results obtained in this study reveal that T. asperelloides PSU-P1 exhibited antifungal activity by mycoparasitism and enhanced defense response in muskmelon through the production of defense-related enzymes and cell wall degrading enzymes. High activities of the enzymes are associated with systemic resistance in muskmelon against gummy stem blight.

这项研究旨在测试木霉菌种对甜瓜植物中由葫芦丝孢菌引起的树胶茎枯病的抗真菌活性。通过双重培养测定法和预先定殖的方法，筛选了八种木霉菌对葫芦链霉菌，马铃薯葡萄糖琼脂（PDA）的抑制作用。结果表明木霉属。PSU-P1在抑制葫芦链霉菌的真菌生长方面具有优越性。内转录间隔区（ITS）的分子鉴定，RNA聚合酶II（RPB2）和翻译延伸因子1-α（TEF1 - α）基因序列揭示了分离株PSU-P1为木霉曲霉（Trichoderma asperelloides）。为了阐明防御反应，对接种过曲霉PSU的甜瓜幼苗进行了防御相关酶过氧化物酶（POD）和多酚氧化酶（PPO）的酶分析以及细胞壁降解酶几丁质酶和β-1,3-葡聚糖酶的检测。 -P1。结果表明，POD，PPO，几丁质酶和β-1,3-葡聚糖酶的活性均高于对照组。从提取的粗制代谢物T. asperelloides PSU-P1接种甜瓜植物真菌引起的异常形态。接种试验（体内）表明，用甜曲霉处理的甜瓜幼苗。PSU-P1显示出对树胶茎枯萎病的抗性，疾病得分为0.2，疾病严重程度指数（DSI）为10％，低于对照组，后者的疾病得分为2.8和75％DSI。这项研究获得的结果表明，曲霉T. PSU-P1通过霉菌副寄生虫表现出抗真菌活性，并通过产生防御相关酶和细胞壁降解酶而增强了甜瓜中的防御反应。这些酶的高活性与甜瓜对树胶茎枯病的全身抗性有关。