7.5%茶·黄液可溶液剂对水稻稻瘟病病菌抑制作用生测实验
A Bioassay Experiment on the Inhibitory Effect of 7.5% Tea- Yellow Liquid Soluble Agent on Rice Blast Fungus

【目的】稻瘟病是全球水稻生产的主要威胁之一，长期依赖化学农药易引发抗药性问题。【方法】本研究以自主研发的7.5%茶·黄液水剂(植物源杀菌剂)为对象，通过菌丝生长速率法测定其对水稻稻瘟病病菌的抑制作用。实验设置5个浓度梯度(46.9~750 μg/ml)，测定24、48、72小时及5天(120小时)的菌落抑制率，并通过毒力回归分析计算有效抑制中浓度(EC₅₀)。【结果】750 μg/ml浓度下，24小时抑制率达97.8%，5天时仍维持96.6%的高抑制率；EC₅₀值为48.19 μg/ml (稀释约1500倍)，表明其具有强效抑菌能力。药效随浓度降低呈递减趋势，但高浓度处理下持效性显著。【意义】该植物源杀菌剂通过抑制病原菌生长及增强植物抗性，为稻瘟病绿色防控提供了新选择，兼具生态安全与抗药性管理优势。
[Purposes] Rice blast disease is one of the major threats to global rice production, and prolonged reliance on chemical fungicides can lead to increased antifungal resistance and environmental concerns. [Methods] This study focused on the 7.5% tea-yellow liquid solution agent (a plant-based fungicide), against M. oryzae using the mycelial growth rate method. Five concentration gradients (46.9~750 μg/mL) were tested, and colony inhibition rates were measured at 24, 48, 72 hours, and 120 hours (5 days) post-treatment. Toxicity regression analysis was performed to calculate the effective median inhibitory concentration (EC₅₀). [Results] At a concentration of 750 μg/mL, the inhibition rate reached 97.8% after 24 hours and maintained 96.6% even after 5 days (120 hours). The EC₅₀ value was determined as 48.19 μg/mL (equivalent to a dilution of approximately 1500-fold), demonstrating strong antifungal activity. Efficacy exhibited a dose-dependent decline with decreasing concentrations, but high-concentration treatments showed remarkable persistence. [Significances] This plant-derived fungicide offers a novel solution for the green control of rice blast disease by suppressing pathogen proliferation and enhancing plant immunity, combining ecological safety with advantages in antifungal resistance management.