Potencial toxicogénico y presencia de especies filogenéticas del complejo Fg en maizales del noroeste argentino

SAMPIETRO, D.A.; DIAZ, C.G.; GONZALEZ, V.; VATTUONE, M.A.; PLOPER, L.D.; CATALAN, C.A.N.; WARD, T.J.

Rosario, Argentina

Congreso; IX Congreso Nacional de Maíz y Simposio Nacional de Sorgo; 2010

Asociación de Ingenieros Agrónomos del Norte de Buenos Aires (AIANBA)

Fusarium graminearum Schwabe [teleomorfo Gibberella zeae (Schwein.) Petch] is the causal agent involved in maize ear rot. The potential of this pathogen to contaminate cereals with trichothecene mycotoxins is a health risk for both humans and animals. In Argentina, identification of this species has been mostly based on morphological criteria. However, phylogenetic species recognition based on molecular biology techniques has demonstrated that the morphological species F. graminearum is a complex (Fg complex). A survey of ear rot isolates from maize collected in northwest Argentina recovered 66 isolates belonging to the Fg complex. A multilocus genotyping (MLGT) assay for determination of Fg complex species and trichothecene chemotypes was used. In this way, 56 out of the 66 isolates were identified as F. meridionale and the remaining 10 isolates as F. boothii. F. meridionale was fixed for the nivalenol (NIV) chemotype and was the dominant species detected. All of the F. boothii isolates had the 15-acetyldeoxynivalenol (15ADON) chemotype. Our results suggest that F. meridionale and F. boothii may play a substantial role in the infection and trichothecene contamination of maize in northwest Argentina. In addition, dominance of the NIV chemotype among Fg complex isolates from Argentina is unprecedented, and of significant concern to food safety and animal production.