赤水撑绿竹根腐病菌室内药剂筛选

Laboratory screening of fungicides against the pathogen of Bambusa pervariabilis×dendrocalamopsis daii root rot in Chishui

采用生长速率法和悬滴法测定了8种常用杀菌剂对赤水撑绿竹Bambusa pervariabilis×dendrocalamopsis daii根腐病病原菌尖孢镰孢菌Fusarium oxysporum Schlecht菌丝生长和孢子萌发的抑制作用,并测定了杀菌剂对尖孢镰孢菌的毒力。结果表明,各杀菌剂对菌丝生长和孢子萌发有不同程度的抑制作用,其中70%敌磺钠WP、3%广枯灵AS能很好地抑制菌丝生长,而70%敌磺钠WP、3%广枯灵AS、70%甲基硫菌灵WP、10%苯醚甲环唑WG对孢子萌发有较强的抑制作用,抑制率均在80%以上。对菌丝生长与孢子萌发均有明显作用的杀菌剂为70%敌磺钠WP、3%广枯灵AS。毒力测定结果表明,70%敌磺钠WP、3%广枯灵AS对尖孢镰孢菌的毒力最高,其EC50分别为0.072 5,0.112 6μg/mL、其次为70%甲基硫菌灵WP和10%苯醚甲环唑WG,其EC50分别为7.8216,7.318 7μg/mL。其余几种药剂的毒力较差。8种药剂的相关系数均在0.98以上,药剂浓度与抑制作用呈正相关。

The inhibition effect of 8 common fungicides on the mycelial growth and spore germination of the pathogen of Bambusa pervariabilis x dendrocalamopsis daii root rot, Fusarium oxysporum Schlecht, with the methods of growth rate and halaging drop and the toxicity of＇the fungicides on Fusar- ium oxysporum was determined. The results showed the inhibition effects of the fungicides on the myce- lial growth and spore germination were different. Fenaminosulf 70% WP and guangkuling 3% AS inhibited the growth of mecylium well. Fenaminosulf 70% WP,guangkuling 3% AS ,thiaphanate-meth- yl 70% WP and difenoconazole 10% WG had strong inhibition effects on spore germination with inhi- bition rate of 80% or more. Fenaminosulf 70% WP and guangkuling 3% AS had the inhibition effect both on the mycelial growth and spore germination. The results of toxicity determination showed the toxicity of Fenaminosulf 70% WP, guangkuling 3% AS was high and their ECs0 was 0. 0725 and 0. 1126 μg/mL respectively. That of thiaphanate-methyl 70% WP and difenoconazole 10% WG were the next and their ECs0 was 7. 8216 and 7. 3187 μg/mL. The toxicity of the other 4 fungicides was poor. The correlation coefficients of the 8 fungicides were all above 0. 98. The concentration of the fun- gicides was relatively correlated with the inhibition effect.