Trichothecene genotypes and chemotypes in Fusarium graminearum strains isolated from wheat in Argentina

REYNOSO MM; RAMIREZ M L; TORRES AM; CHULZE SN

INTERNATIONAL JOURNAL OF FOOD MICROBIOLOGY

ELSEVIER SCIENCE BV

Año: 2011 vol. 145 p. 444 - 448

0168-1605

Argentina is the fourth largest exporter ofwheat in theworld. Themain pathogen associated with Fusarium Head Blight (FHB) of wheat in Argentina is Fusariumgraminearumlineage 7 also termed F. graminearumsensu stricto in the F. graminearumspecies complex,which can produce the Type B trichothecenes, usually deoxynivalenol (DON) and its acetylated forms (3-ADON and 15-ADON) or nivalenol (NIV).We used a multiplex PCR assay of Tri3, Tri7, and Tri13 to determine the trichothecene genotype of 116 strains F. graminearum collected from three locations in Argentina and then verified the chemotype by chemical analysis. PCR assays and chemical analyses gave the same results for all strains that produced trichothecenes. Most strains (92%) had the 15-ADON genotype, with the remaining strains having the DON/NIV genotype. We observed neither the NIV nor the 3-ADON genotypes amongst the strains evaluated. The nine strains with the DON/NIV genotype produced DON when analyzed chemically. Thus, the Argentinean populations of F. graminearumare similar to those fromwheat elsewhere in the world, in that all the strains produced DON/15-ADON and belong to lineage 7. However approximately 8% of the strains tested were incorrectly diagnosed as DON/NIV producers with the current multiplex PCR and were only DON producers by chemical analysis