Phylogenetic species and trichothecene genotypes within Fusarium graminearum species complex isolates from soybean in Argentina and Brazil

BARROS GERMAN; CHIOTTA MARIA LAURA; TESSMAN DAURI; CHULZE SOFIA

Medellín

Congreso; VIII Congreso Latinoamericanp de Micología; 2014

Members of the Fusarium graminearum species complex (FGSC) can infect several crops causing diseases such as Fusarium Head Blight in wheat, and root rot in soybean. This complex include at least 16 phylogenetically distinct species with marked biogeographic structure. These species can contaminated the grains with B trichothecenes such as deoxynivalenol (DON), nivalenol (NIV) and its acetylated forms. Several studies conducted in Argentina and Brazil on wheat demonstrated that F. graminearumsensu stricto is the dominant species within the FGSC. However, there is little information about the FGSC composition in soybean crop in both countries. The aims of this work were: i) to characterize the phylogenetic species composition within the FGSC isolated from soybean in Argentina and Brazil and ii) to determine the trichothecene genotype using a multiplex PCR analysis. The sequence analysis of the translation elongation factor 1α (TEF-1) gene, the trichothecene 3-o-acetyltransferase (TRI 101) gene and putative reductase (RED) genes showed the presence of four species within the FGSC in Argentinean soybean isolates. These included F. graminearum, which was the predominant speciesand showed simultaneous production of DON/15-ADON (15-ADON genotype); F. meridionale and F. cortaderiae with simultaneous production of DON/NIV (DON/NIV genotype) and F. boothii with trichothecenes production similar to F. graminearum. Among the Brazilian soybean isolates, three phylogenetic species were characterized: F. graminearum, F. meridionale and F. austroamericanum showing 15-ADON, NIV and 3-ADON genotype, respectively. In conclusion, the sequence analysis showed higher species diversity in soybean compare to the wheat populations characterized in Argentina and Brazil. Additional sampling on different soybean-growing regions and further sequence analysis will be needed to confirm the role of soybean crop as a population reservoir of several species within the FGSC.