鱼类水霉病植物源性杀菌剂的筛选

Screening of Botanical Fungicides for Fish Water Mildew

为探究鱼类水霉病植物源性杀菌剂的抑菌效果,以水霉病菌为供试病菌,选取了多种具有消炎、杀菌功效的药用植物进行抑菌活性筛选,以抑菌圈直径大小为指标,确定植物提取物对水霉菌的抑菌效果;筛选抑菌效果较强的植物提取物,测定其对水霉菌的最低抑菌浓度(MIC)、最低杀菌浓度(MBC),以及其对水霉菌生长抑制率、菌丝生长量的影响。结果表明:黄连、油茶饼、大黄等植物提取液对水霉菌的生长具有较强抑制效果;三者对水霉菌的MIC值均较低,分别为3.125、6.25、12.5mg/mL,对水霉菌的MBC值相差不大,均在为50 mg/mL左右。总体上,黄连表现出了相对最优的抑菌效果,当黄连提取液处理浓度达到500 mg/L时,抑菌率达到97%以上,菌丝鲜重低于0.02 g,抑菌效果最佳。

To explore t the antibacterial effect of plant extracts against Botryosphaeria dothidea, and to provide direction for the development and use of safe and effective drugs for the treatment. In this paper, Botryosphaeria dothidea was used as test pathogens. A variety of plants with anti-infammatory and bactericidal were selected for antibacterial activity screening. The growth rate and growth of mycelia were used as indicators to determine the antibacterial effect of plant extracts on Botryosphaeria dothidea. Then, the plant extracts with effective antibacterial effect were selected to determine the minimum inhibitory concentration （MIC）, the minimum bactericidal concentration （MBC）, and the growth inhibition rate and mycelial growth of Botryosphaeria dothidea. The experimental results showed that the extracts of Coptis chinensis, Camellia and Rheum palmatum have effective inhibitory effects on the growth of Botryosphaeria dothidea. The MIC values of the three extracts were 3.125 mg/mL, 6.25 mg/mL and 12.5 mg/mL, there was no signifcant difference in the MBC values, and they were all around 50 mg/mL. In general, Coptis chinensis showed the best antibacterial effect, when the concentration of Coptis chinensis extract reached 500 mg/L, the antibacterial rate reached more than 97%, and the fresh weight of hyphae was less than 0.02 g.