Genotypic diversity and mycotoxin production of Fusarium graminearum isolates from wheat cultivated in Argentina

CORA LILIA ALVAREZ, MARIELA PAMELA AZCARATE, LAURA TERMINIELLO, DANIEL CABRAL, GRACIELA VAAMONDE Y VIRGINIA FERNÁNDEZ PINTO

Research and Reviews in Biosciences

Trade Science Inc

Lugar: India; Año: 2007 p. 172 - 180

Fusarium head Blight(FHB) is an important disease affecting the productionof wheat worldwide, that causes economic losses due to reduction in seedquality and presence of mycotoxins. The objective of the present work wasto determine genotypic diversity and toxin production profile of Fusariumgraminearum from wheat cultivated in 19 districts of Buenos Aires province,Argentina. Vegetative Compatibility(VC) and Mycelial Compatibility (MC)were used to study genotypic diversity. Fifty isolates of F. graminearumwere studied, which formed 32 Mycelial Compatibility Groups (MCGs); inwhich 12 out of 32 were multimembers groups. Nitrate non utilizing mutantswere obtained from 34 isolates, that which ones analyzed by VC, formed 28Vegetative Compatibility Groups(VCGs) with 4 multimembers VCGs. The variabilityindex was 0.82 for VC and 0.64 for MC. Forty-four out of 50 isolatesproduced Deoxynivalenol(DON)(0.19 to 2169.3g g-1). The co-occurrence ofDON- and Nivalenol(NIV) was detected in 27 isolates, with NIV levels between0.1 and 14.3µg g-1. Simultaneous production of DON and both acetylderivatives were found in 27 isolates; DON, NIV and 15 acetyl DON were coproducedby 27 isolates, being these two the most frequent mycotoxin productionprofile. There was found that 41.67% of the multimember MCGsshared a similar toxin production profile. These results suggest a high diversityin the F.graminearum population from Argentinean wheat that shouldbe taken into account to design better control strategies for FHB and suitablemethods to analyse toxin contents in food and feed.