Silver nanoparticles (Ag NP) were synthesized using rice leaf extract and optimized synthetic conditions were found to be 0.4 % leaf extract, 0.6 mM AgNO3 and 30 min of autoclaving. Produced NP were characterized using UV-vis, DLS, zeta potential, XRD, TEM and FTIR. Ag NP formation was established from UV-vis spectra and NP showed zeta potential value of -27.4 mV. NP were spherical, polydisperse and average size was 16.5 ± 6.2 nm. Antifungal activity of Ag NP was assessed by poisoned food technique and resazurin broth dilution against mycelium and sclerotia of fungus R. solani, the causative agent of sheath blight disease in rice. Results confirmed effective hyphal growth inhibition and % growth inhibition was dose dependent (2.5-10 μg/mL). Ag NP showed enhanced mycelial inhibition (81.7-96.7 %) at 10 μg/mL. MIC values of Ag NP were in the range of 5-10 and 15-20 μg/mL towards fungal mycelium and sclerotia, respectively. Ag NP treatment (20 μg/mL) completely inhibited the disease incidence at 20 μg/mL. Ag NP treatment (10 μg/mL) caused 1.3 and 1.5 times enhancement in seedling vigor index. Hence, Ag NP can be utilized towards management and control of various fungal diseases of crops.

中文翻译：

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稻叶提取物合成银纳米粒子：对水稻纹枯病病原体的体外杀菌评价

银纳米粒子 (Ag NP) 是使用稻叶提取物合成的，发现优化的合成条件是 0.4% 的叶提取物、0.6 mM AgNO3 和 30 分钟的高压灭菌。使用 UV-vis、DLS、zeta 电位、XRD、TEM 和 FTIR 对生成的 NP 进行表征。Ag NP 的形成是从 UV-vis 光谱确定的，NP 显示出 -27.4 mV 的 zeta 电位值。NP 是球形的、多分散的，平均尺寸为 16.5 ± 6.2 nm。Ag NP 的抗真菌活性通过中毒食物技术和刃天青肉汤稀释对真菌 R. solani（水稻纹枯病的病原体）的菌丝体和菌核进行评估。结果证实有效的菌丝生长抑制和％生长抑制是剂量依赖性的（2.5-10 μg/mL）。Ag NP 在 10 μg/mL 时显示出增强的菌丝体抑制 (81.7-96.7%)。Ag NP 对真菌菌丝体和菌核的 MIC 值分别在 5-10 和 15-20 μg/mL 的范围内。Ag NP 处理 (20 μg/mL) 在 20 μg/mL 时完全抑制了疾病的发生。Ag NP 处理 (10 μg/mL) 导致幼苗活力指数提高 1.3 倍和 1.5 倍。因此，Ag NP 可用于管理和控制作物的各种真菌病害。