Analysis of azole fungicide resistance in Mycosphaerella fijiensis, causal agent of black Sigatoka.


Abstract:

Mycosphaerella fijiensis causes black Sigatoka, economically the most important disease in bananas and plantains. Disease control is mainly achieved through the application of specific fungicides, including azoles. However, their intensive use has favoured the appearance of resistant strains. In this study, we examined the variation in sensitivity to azole fungicides in field isolates of M. fijiensis collected in Ecuador, Brazil, Costa Rica, Africa, and Southeast Asia using a 96-well microtitre plate assay. The isolates tested showed a wide range in sensitivity to the azole fungicides cyproconazole, propiconazole and imazalil. A clear pattern of cross-sensitivity was found among the isolates for cyproconazole and propiconazole. Sequence analysis of the CYP51 gene amplified from sensitive and resistant strains, showed the presence of several point mutations located around the putative substrate binding site in the encoded protein. The most common mutations detected were Y136F, A313 G, Y463D, Y463H, Y463N, and Y463S. This study provides important preliminary information for the understanding of the mechanisms of azole resistance in this fungus and in the future will help to optimize the use of azoles in the control of black Sigatoka.

Año de publicación:

2011

Keywords:

    Fuente:

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    Tipo de documento:

    Other

    Estado:

    Acceso abierto

    Áreas de conocimiento:

    • Fitopatología
    • Ciencias Agrícolas
    • Microbiología

    Áreas temáticas:

    • Lesiones, enfermedades y plagas de las plantas
    • Técnicas, equipos y materiales