[Objective] The paper was to clarify the sensitivity and resistance of Pseudoperonospora cubensis to cymoxanil.[Method] A total of 69 strains were collected from 13 major cucumber producing areas in eight provinces an...[Objective] The paper was to clarify the sensitivity and resistance of Pseudoperonospora cubensis to cymoxanil.[Method] A total of 69 strains were collected from 13 major cucumber producing areas in eight provinces and cities of Guangdong, Hubei, Jiangsu, Shandong, Beijing, Liaoning, Jilin and Heilongjiang from 2012 to 2016, and their sensitivity and resistance to cymoxanil was determined using leaf disc floating method.[Result] The EC50 of cymoxanil to P. cubensis were 0.006 8-0.134 1 μg/mL and the average EC50 was 0.062 4 μg/mL. The sensitivity of P. cubensis to cymoxanil presented a single-peak curve, which was approximately normal distribution, and no strains with decreased sensitivity were found. The average EC50 (0.062 4 μg/mL) could be used as the sensitivity baseline of P. cubensis to cymoxanil. Among the 69 strains, 16 were low-resistance strains, accounting for 23.19% of the total strains;53 were sensitive strains, accounting for 76.81%, which were dominant populations;and no medium-resistance and high resistance strains were found. The resistance of P. cubensis to cymoxanil ranged from 0.11 to 2.15 times, and the average resistant level was 1.00 times.[Conclusion] Cymoxanil showed strong inhibitory effect against P. cubensis.展开更多
基金Supported by Northeast Agricultural University Student SIPT ProjectNational Natural Science Foundation of Heilongjiang Province(ZD2016003)
文摘[Objective] The paper was to clarify the sensitivity and resistance of Pseudoperonospora cubensis to cymoxanil.[Method] A total of 69 strains were collected from 13 major cucumber producing areas in eight provinces and cities of Guangdong, Hubei, Jiangsu, Shandong, Beijing, Liaoning, Jilin and Heilongjiang from 2012 to 2016, and their sensitivity and resistance to cymoxanil was determined using leaf disc floating method.[Result] The EC50 of cymoxanil to P. cubensis were 0.006 8-0.134 1 μg/mL and the average EC50 was 0.062 4 μg/mL. The sensitivity of P. cubensis to cymoxanil presented a single-peak curve, which was approximately normal distribution, and no strains with decreased sensitivity were found. The average EC50 (0.062 4 μg/mL) could be used as the sensitivity baseline of P. cubensis to cymoxanil. Among the 69 strains, 16 were low-resistance strains, accounting for 23.19% of the total strains;53 were sensitive strains, accounting for 76.81%, which were dominant populations;and no medium-resistance and high resistance strains were found. The resistance of P. cubensis to cymoxanil ranged from 0.11 to 2.15 times, and the average resistant level was 1.00 times.[Conclusion] Cymoxanil showed strong inhibitory effect against P. cubensis.
