Activity of the Fungicide JS']JS399-19 Against Fusarium Head Blight of Wheat and the Risk of Resistance

This report reviews the characteristics of JS399-19, a novel cyanoacrylate fungicide. JS399-19 strongly inhibits the mycelial growth of the fungal plant pathogens of the genus Fusarium and exhibits great potential in controlling Fusarium head blight (FHB) on wheat and other cereals. The mode of action of JS399-19 is evidently different from that of benzimidazole (for example, carbendazim) and other sort of fungicides, making it a possible replacement for carbendazim in China to manage carbendazim-resistant subpopulations of Fusarium graminearum and F. asiaticum. JS399-19 has excellent protective and curative activity against these pathogens. Incorrect use of this fungicide, however, is likely to select for resistance. Among JS399-19-resistant mutants of F. asiaticum induced in the laboratory, the resistant level of mutants was high and the phenotype of resistance against JS399-19 was conferred by a major gene by genetic analysis. The fitness of laboratory-induced JS399-19-resistant mutants of F. asiaticum was nearly equal to that of their parents. JS399-19 lacks cross resistance with other sort fungicides. To control FHB with JS399-19 and to delay the development of the fungicide-resistance, farmers should use tank mixtures containing JS399-19 and carbendazim, metconazole, tebuconazole, or prothioconazole.