【摘要】 为了明确安徽地区辣椒疫霉对甲霜灵的抗药性水平及抗性菌株的地理分布,2005—2006年从安徽省16个市、县采集辣椒疫病病株,经分离纯化鉴定,获得125株辣椒疫霉菌株,分别采用生长速率法和叶盘漂浮法测定其对甲霜灵的敏感性。结果表明,按照Parra&Ristaino(2001)标准,供试菌株中有79株对甲霜灵敏感,38株对甲霜灵敏感性处于中间状态,8株抗甲霜灵,即敏感菌株、中间菌株和抗性菌株分别占总体的63.2%、30.4%和6.4%。采自不同地区的菌株对甲霜灵的敏感性差异较大,其中以寿县的菌株最为敏感,EC50值最低为0.10μg/mL,平均为0.81±0.20μg/mL;而砀山、和县地区的菌株表现出一定的抗药性,平均EC50为8.32±0.19μg/mL,最高达25.47μg/mL。抗性菌株的最高抗性倍数约为90倍。更多还原

【Abstract】 In order to investigate the resistance level and geographical distribution of resistant isolates in Phytophthora capsici to metalaxyl in Anhui,about 200 samples of pepper Phytophthora blight were collected in major vegetable growing areas among 16 cities and counties of the province during 2005-2006,and 125 strains of P.capsici were isolated and purified from these samples.The sensitivity of these strains to metalaxyl was determined by mycelial growth rate method in vitro and biological test in vivo,respectively.The results showed that 79 isolates were sensitive to metalaxyl(<40% growth at 5.0μg/mL of metalaxyl),38 isolates intermediate in sensitivity to metalaxyl(>40% growth at 5.0μg/mL of metalaxyl and <40% growth at 100μg/mL of metalaxyl),and 8 isolates resistant to metalaxyl(>40% growth at 100μg/mL of metalaxyl) according to Parra & Ristaino’s(2001) criterion.The proportion of metalaxyl-sensitive isolates(MS),metalaxyl-intermediate isolates(MI) and metalaxyl-resistant isolates(MR) covered 63.2%,30.4% and 6.4% in P.capsici isolate population,respectively.There was also a significant difference in the sensitivity of the strains from different areas to metalaxyl.The strains from Shouxian were the most sensitive,with the minimum and mean EC50 value being 0.10μg/mL and 0.81±0.20μg/mL,respectively,while the strains from Dangshan and Hexian represented the resistance,with the mean EC50 value being more than 8.32±0.19μg/mL,and the maximum 25.47μg/mL,which suggested the highest resistant level was about 90 folds.更多还原