Sensitivity of Fusarium fujikuroi to prochloraz and JS399-19 in Jiangsu Province

Samples of rice bakanae disease were collected from Jiangyan, Jingjiang, Changzhou in Jiangsu Province. Seventy seven isolates of Fusarium fujikuroi were identified, and their sensitivity to prochloraz and JS399-19 were investigated using mycelium growth inhibition method. The results exhibited that the EC50 values of prochloraz to F. fujikuroi isolates were from 0.020 to 1.333 μg/mL. Among the 77 F. fujikuroi isolates, 18 isolates exhibited medium level resistance to prochloraz, with a frequency of 23.38%;while 59 isolates showed high level resistance, with a frequency of 76.62%. The resistant population of F. fujikuroi to prochloraz was dominant in Jiangsu Province. The EC50 values of JS399-19 to F. fujikuroi isolates were from 0.0124 to 2.040 μg/mL, and the sensitivity frequency of F. fujikuro isolates to JS399-19 exhibited a Gaussian distribution, with mean EC50 value (0.684±0.265) μg/mL, which could be considered as sensitivity baseline of F. fujikuro to JS399-19 in Jiangsu Province.