黄瓜褐斑病防治药剂的离体活性筛选

离体条件下针对黄瓜褐斑病菌对19种杀菌剂进行了活性筛选。结果表明，不同杀菌剂对褐斑病菌菌丝生长和孢子萌发抑制作用不同。对褐斑病菌菌丝生长具有强烈抑制作用的杀菌剂为苯醚甲环唑、咪鲜胺、代森锰锌及嘧霉胺，其EC50分别4.21、4.67、5.59 μg/mL及4.11 μg/mL。甲氧基丙烯酸酯类杀菌剂及防治卵菌病害的药剂对褐斑病菌菌丝生长几乎没有影响。烯肟菌酯、福美双、代森锰锌、烯酰吗啉、百菌清和多菌灵对褐斑病菌孢子萌发具有强烈抑制作用，其EC50分别为3.34、6.62、0.28、3.54、0.53 μg/mL及0.26 μg/mL。50 μg/mL的嘧霉胺虽对孢子萌发抑制作用较小，但10 μg/mL时即可导致萌发的芽管出现明显卷曲、畸形。

In vitro screening of effective fungicides against Corynespora cassiicola

Nineteen fungicides were chosen to investigate their effectiveness against Corynespora cassiicola in vitro. The results showed that the fungicides had different activities against mycelial growth and spore germination of C. cassiicola. The fungicides with strong activity against mycelial growth were difenoconazole, prochloraz, mancozeb and pyrimethanil, with their EC50 values as 4.21, 4.67, 5.59 and 4.11 μg/mL, respectively. The strobilurins and fungicides for controlling oomycete diseases almost had no effects on mycelial growth and spore germination. The best fungicides against spore germination were enestroburin, thiram, mancozeb, dimethomorph, chlorothalonil and carbendazim, with their EC50 values as 3.34, 6.62, 0.28, 3.54, 0.53 and 0.26 μg/mL, respectively. Though pyrimethanil at 10 μg/mL showed a low activity against spore germination, it could induce tube deformity.