Abstract The effect of bio-agent Bacillus subtilus, nano titanium dioxide (TiO2) and Zinc oxide (ZnO) as well as the combination compared with fungicide (Topas100) was investigated under laboratory (in vitro) and greenhouse conditions against powdery mildew disease caused by Podosphaera xanthii. Most of treatments were strong to inhibit the spore germination of P. xanthii. B. subtilus and B. subtilus + nano-Tio2 were the most effective followed by Topas100, B. subtilus + nano-ZnO, nano-ZnO and Nano-TiO2 compared with control. Most of treatments significantly reduced the disease symptoms and diseases severity (%) particularly bio-agent, nano-ZnO and combination of B. subtilus + nano-ZnO, however, the fungicide treatment showed the best inhibition. As a consequence of treatments histo-biochemical and growth parameters of cucumber were changed. Reactive oxygen species (hydrogen peroxide and superoxide) were accumulated early. Chlorophyll content, catalase, peroxidase, and polyphenol oxidase activities were increased under various treatments, however, electrolyte leakage (EL) was decreased. The growth characters e.g. plant height, leaves number, fresh and dry weight/plant was significantly improved because of treatments. Combined of B. subtilus and nano-Zinc oxide treatment was the best treatment and promising to be an alternative to fungicide, consequently, decreasing the environmental pollution, cost and harmful effect of fungicide on human health.

中文翻译：

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枯草芽孢杆菌作为生物制剂结合纳米分子可通过黄瓜植株的组织化学和生理生化变化防治白粉病

摘要 研究了生物制剂枯草芽孢杆菌、纳米二氧化钛 (TiO2) 和氧化锌 (ZnO) 以及与杀菌剂 (Topas100) 相比的组合在实验室（体外）和温室条件下对由白粉病引起的白粉病的影响。 Podosphaera xanthii。大多数处理对抑制 P. xanthii 的孢子萌发具有很强的抑制作用。与对照相比，枯草芽孢杆菌和枯草芽孢杆菌 + 纳米二氧化钛最有效，其次是 Topas100、枯草芽孢杆菌 + 纳米氧化锌、纳米氧化锌和纳米二氧化钛。大多数处理显着降低了疾病症状和疾病严重程度（%），尤其是生物制剂、纳米氧化锌和枯草芽孢杆菌+纳米氧化锌的组合，但杀菌剂处理显示出最好的抑制作用。作为处理的结果，黄瓜的组织生化和生长参数发生了变化。活性氧（过氧化氢和超氧化物）在早期积累。叶绿素含量、过氧化氢酶、过氧化物酶和多酚氧化酶活性在各种处理下增加，但电解质泄漏 (EL) 减少。由于处理，生长性状例如株高、叶数、鲜重和干重/株显着改善。枯草芽孢杆菌与纳米氧化锌联合处理是最好的处理方法，有望成为杀菌剂的替代品，从而降低杀菌剂对环境的污染、成本和对人体健康的危害。由于处理，生长性状例如株高、叶数、鲜重和干重/株显着改善。枯草芽孢杆菌与纳米氧化锌联合处理是最好的处理方法，有望成为杀菌剂的替代品，从而降低杀菌剂对环境的污染、成本和对人体健康的危害。由于处理，生长性状例如株高、叶数、鲜重和干重/株显着改善。枯草芽孢杆菌与纳米氧化锌联合处理是最好的处理方法，有望成为杀菌剂的替代品，从而降低杀菌剂对环境的污染、成本和对人体健康的危害。