烟草黑胫病菌对甲霜灵的抗药性风险

Resistance Risk of Phytophthora parasitica var. nicotianae to Metalaxyl

为了评估烟草黑胫病菌对甲霜灵的抗药性风险,以对甲霜灵敏感和高抗的烟草黑胫病菌240和191为出发菌株,进行了抗性突变频率测定、抗性诱变、抗性水平测定、遗传稳定性、生长速率、致病性测定和适合度等研究。结果表明,烟草黑胫病菌对甲霜灵敏感的240菌株在含10mg/L甲霜灵的CA平板上的抗性突变频率为7.0×10-5。分别以药剂诱变和紫外诱变获得了抗甲霜灵菌株240-YY和240-ZY。对甲霜灵敏感性不同的烟草黑胫病菌适合度测定结果表明,抗性菌株在潜伏期、侵染率、病情指数和病斑面积等方面均具有较高的适合度水平。研究结果显示,烟草黑胫病菌对甲霜灵具有较大的抗药性风险。

In order to evaluate resistance risk of Phytophthora parasitica var. nicotianae to metalaxyl, the metalaxyl-sensitive strain 240 and metalaxyl-resistant strain 191 were studied. The results showed that the mutation rate of metalaxyl-sensitive strain 240 was 7.0 × 105 on CA medium with metalaxyl concentration of 10 mg/L. The metalaxyl- resistant strains 240-YY and 240-ZY were obtained through mutagenesis of metalaxyl and ultraviolet radiation, respectively. The test results suggested that the metalaxyl-resistant strains of Phytophthora parasitica var. nicotianae had quite high level of fitness on their latent period, infection frequency, disease index and lesion area. The results indicated that there might be a high resistance risk for the Phytophthora parasitica var. nicotianae to metalaxyl.