摘要
采用生长速率法测定精甲霜灵、外消旋体甲霜灵及其混配药剂对掘氏疫霉菌PhytophthoradrechsleriTucker的杀菌毒力。应用不同药剂浓度的白云豆液体和固体带毒培养基培养法及玻璃纸培养法测定甲霜灵、精甲霜灵对病原菌菌丝生长、孢子囊萌发和游动孢子产生的影响,采用电导法测定药剂对病原菌细胞膜通透性的影响。实验结果表明,精甲霜灵和外消旋体甲霜灵对掘氏疫霉菌的EC50值分别为0.129μg/mL和0.427μg/mL;两者分别与代森锰锌按照质量比5∶48的配比混配,共毒系数分别为101.6和95.9,对防治由掘氏疫霉菌引起的西瓜疫病具有加和作用。甲霜灵和精甲霜灵对病原菌菌丝的生长和孢子囊的产生都有很高的抑制活性,当药剂浓度为0.3～0.7μg/mL时,精甲霜灵对菌丝生长的抑制率为39.28%～84.39%,明显优于甲霜灵的28.36%～66.56%。药剂浓度为30.0～70.0μg/mL时,精甲霜灵对孢子囊产生的抑制率为42.7%～98.3%,优于甲霜灵的25.1%～89.5%。两种药剂对孢子囊的萌发没有明显影响;精甲霜灵对病原菌细胞膜通透性的影响高于甲霜灵。
Toxicity of metalaxylM, metalaxyl and their mixtures to Phytophthora drechsleri were determined by means of growth rate, respectively. Effect of metalaxylM and metalaxyl on hypha growth, sporangium germination, swarm sporangium formation were examined by the ways of liquidsolid white lupine media mixed with fungicide of different concentration. The result indicated that the EC50 of metalaxylM and metalaxyl were 0.129 μg/mL and 0.427 μg/mL . The common toxicity index of mixture 1 containing metalaxylM and mancozeb (5∶48, m/m) and mixture 2 containing metalaxyl and mancozeb (5∶48, m/m) were 101.6 and 95.9, respectively. MetalaxylM and mixture 1 showed more effective toxicity to Phytophthora drechsleri than that of metalaxyl and mixture 2. MetalaxylM had higher inhibitory action on hypha growth and sporangium formation than that of metalaxyl under the same concentration. When the concentration was 0.3～0.7 μg/mL and 30.0～70.0 μg/mL respectively, the inhibition rate of metalaxylM and metalaxyl to the growth of hypha were 39.28%～84.39% and 28.36%～66.56%, to sporangium formation were 42.7%～98.3% and 25.1%～89.5%, but metalaxylM or metalaxyl had no inhibitory activity to sporangium germination. Effect of fungicides on the cell membrance potential of Phytophthora drechsleri was tested by the conductivity method, which reveal that metalaxylM made a significant infection on cell membrance than that of metalaxyl.
出处
《农药学学报》
CAS
CSCD
2003年第3期45-49,共5页
Chinese Journal of Pesticide Science
基金
农药化学及农药使用技术农业部重点开放实验室开放基金资助项目.
关键词
精甲霜灵
手性异构体
毒力测定
抑菌作用
metalaxyl-M
stereoisomers
toxicity testing
inhibitory action
