Saprolegniasis which is caused mainly by Saprolegnia sp. is the main cause of the winter mass kills in northern freshwater fish farms in Egypt. Various treatment protocols were used to control it, but they are not favoured due to toxicity and cost of treatment; thus, the search for safer economic alternative is ongoing. In this study, 50/59 plant/plant parts methanolic extracts were screened for the possible anti‐fungal activity against a locally isolated Saprolegnia parasitica strain by agar plate dilution method. The screening revealed a significant inhibition of S. parasitica produced by 8 plant extracts, in which the highest inhibition rate was produced by Cyperus esculentus rhizomes, and the least efficacy amongst them belonged to Juniperus phoenicea fruits. Afterwards, the minimum inhibitory concentration (MIC) by the macrodilution broth assay was performed for them, which revealed that C. esculentus and Carthamus tinctorius extracts were the most effective with concentration of 0.1 ppm while the least activity among the effective extracts belonged to Chenopodium murale, Ipomoea batatas and Luffa aegyptiaca (fruit rend) with concentration of 10 ppm. In the present study, it was concluded that the methanolic extracts of C. esculentus rhizomes, C. murale whole plant, C. tinctorius flowers, I. batatas leaves, J. phoenicea fruits, L. aegyptiaca leaves and fruit rend, and Ricinus communis leaves, showed high inhibitory action against Saprolegnia in low concentrations, which may lead to their future usage in the aquaculture application.

中文翻译：

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体外筛选某些埃及植物提取物对鱼类病原菌Saprolegnia parasitica的抗真菌活性

腐烂症主要由腐烂菌引起。是造成埃及北部淡水养鱼场冬季大规模杀害的主要原因。人们采用了各种治疗方案来控制它，但是由于毒性和治疗费用而并不受欢迎。因此，正在寻求更安全的经济替代方案。在这项研究中，通过琼脂平板稀释法筛选了50/59植物/植物部位的甲醇提取物对本地分离的Saprolegnia parasitica菌株的抗真菌活性。筛选显示出对8种植物提取物产生的寄生链球菌有明显的抑制作用，其中香附子产生的抑制率最高。根状茎，其中功效最小的属于凤梨果实。然后，由大量稀释肉汤测定最小抑制浓度（MIC）是为他们执行，这表明，C.荸荠和红花提取物是最有效的与0.1ppm的浓度，同时有效提取物中的最小活动属于藜murale，番薯（Ipomoea batatas）和埃及伊瓜（Luffa aegyptiaca）（浓度为10 ppm）。在本研究中，得出的结论是，番茄的根茎，子整个植物，丁香的甲醇提取物。花，甘薯叶，J. phoenicea水果，L. aegyptiaca叶子和果实雷德和蓖麻叶，表现出对高抑制作用水霉在低浓度下，这可能导致他们今后在水产养殖应用程序使用。