辣椒疫病防治剂的室内筛选*

 用菌丝生长抑制法和孢子囊萌发抑制法分别测定了烯酰吗啉、氢氧化铜、王铜、甲霜灵、福美双、三乙膦酸铝、氨基寡糖素、霜霉威、百菌清、代森锰锌等10种杀菌剂对辣椒疫霉菌的毒力。结果表明,烯酰吗啉对辣椒疫霉菌菌丝生长的抑制效果最好,EC₅₀为1.06 μg/mL；氢氧化铜对孢子囊萌发的抑制效果最好,EC₅₀为1.68 μg/mL；代森锰锌对菌丝生长和孢子囊萌发也具有较好的抑制作用；霜霉威对辣椒疫霉菌的菌丝生长和孢子囊萌发几乎都没有抑制作用。对辣椒疫霉菌产孢子囊培养基的筛选结果为米糠琼脂培养基为最佳培养基,产孢子囊量最多且个体较大、均匀一致。

Screening of the Fungicides against Phytophthora Blight of Pepper

The toxicity of 10 fungicides (dimethomorph,cupric hydroxide,copper oxychloride,metalaxyl,thiram,fosetyl-aluminium,oligosacchari,propamocarb,chlorothalonil and mancozeb) to Phytophthora capsici Leonian were determined by inhibiting mycelium growth and germination of zoosporangia of the fungus in vitro,respectively. The results showed that dimethomorph had substantial inhibitory activity against mycelium growth with EC₅₀ 1.06 μg/mL and cupric hydroxide was effective on inhibiting germination of zoosporangia with EC₅₀ 1.68 μg/mL. Mancozeb had a little less inhibitory activity against mycelium growth and germination of zoosporangia,while propamocarb had almost no activity on the two phases of the pathogen. The screening of culture medium to produce zoosporangia indicated that rice bran agar culture medium was optimal for production of zoosporangia of the oomycete and P. capsici. Zoosporangia produced by the culture medium were enough in quantity,bigger and almost in the same size.