ISOZYMIC AND PATHOGENIC VARIATIONS OF Fusarium spp. ASSOCIATED WITH VANILLA STEM AND ROOT ROTTING

Abstract

This study determined the pathogenic and isozymic variations of Fusarium spp. isolates associated with the stem and root rotting of a vanilla cultivar in the Totonacapan region, Veracruz, Mexico. Pathogenicity patterns and esterase isozymes profiles of the isolates evaluated revealed that not only morphological and pathogenic variability exists, but also a high level of biochemical variability within the fungi responsible for stem rotting in Vanilla planifolia Jacks. ex Andrews. The production of some esterases (band Rf = 0.75) appears to be associated with the pathogenicity of the fungi, since their presence was not detected in the isolates that were non pathogenic to the crop. This biochemical marker might be a fast, reliable and inexpensive alternative, in relation with other well established molecular technologies, to assess the pathogenicity of Fusarium spp. in V. planifolia, as well as other species or races of this genus that cause stem and root rotting in the crop.