College of Plant Protection, Shandong Agricultural University, Shandong Provincial Key Laboratory for Biology of Vegetable Diseases and Insect Pests, Tai'an, Shandong 271018, P.R. China.
Plant Dis. 2018 May;102(5):863-868. doi: 10.1094/PDIS-09-17-1396-RE. Epub 2018 Feb 28.
Tetramycin is a new biopesticide that combines high-level and broad-spectrum fungicidal activity, low toxicity, and environmental safety. In this study, 90 Phytophthora capsici isolates obtained from various regions in southern China were characterized for their baseline sensitivity to tetramycin. The protective and curative activities of tetramycin against P. capsici were determined on leaves of pepper, and the control efficacy of tetramycin in greenhouse experiments was also determined. Compared with mycelial growth, the formation of sporangia and the discharge of zoospores were inhibited by lower concentrations of tetramycin, approximately 5 µg ml on V8 media. The frequency distribution curves for the tetramycin sensitivity were unimodal, with mean values for the fungicide concentration that reduced mycelial growth, sporangia formation, and zoospore discharge by 50% compared with the control of 1.18 ± 0.91, 0.64 ± 0.42, and 0.63 ± 0.30 µg ml, respectively. In addition, no correlation was observed between tetramycin and other fungicides tested, including mandipropamid, azoxystrobin, mefenoxam, fluazinam, fluopicolide, and famoxadone. Tetramycin exhibited both protective and curative effects against P. capsici in vitro, and its protective activity was better than its curative activity. In greenhouse experiments, tetramycin concentration of 60 and 90 µg ml provided a protective control efficacy of 47.1 to 56.4% and curative efficacy of 43.3 to 52.7%. These results demonstrated that tetramycin could serve as an excellent alternative fungicide to control Phytophthora blight of pepper.
四霉素是一种新型生物农药，兼具高效广谱的杀菌活性、低毒性和环境安全性。本研究对采自中国南方不同地区的 90 个辣椒疫霉菌分离物进行了基础敏感性测定。测定了四霉素对辣椒叶片的保护和治疗活性，并在温室试验中测定了四霉素的防治效果。与菌丝生长相比，较低浓度的四霉素（V8 培养基中约为 5μg/ml）抑制了游动孢子囊的形成和游动孢子的释放。四霉素敏感性的频率分布曲线呈单峰型，与对照相比，抑制菌丝生长、游动孢子囊形成和游动孢子释放 50%的杀菌剂浓度的平均值分别为 1.18±0.91、0.64±0.42 和 0.63±0.30μg/ml。此外，四霉素与其他测试的杀菌剂（如 mandipropamid、azoxystrobin、mefenoxam、fluazinam、fluopicolide 和 famoxadone）之间没有相关性。四霉素对辣椒疫霉具有保护和治疗作用，其保护活性优于治疗活性。在温室试验中，60 和 90μg/ml 的四霉素浓度提供了 47.1%至 56.4%的保护防治效果和 43.3%至 52.7%的治疗防治效果。这些结果表明，四霉素可以作为防治辣椒疫病的优良替代杀菌剂。
