Genotypic Diversity And Mycotoxin Production Of Fusarium Graminearum
Isolates From Wheat Cultivated In Argentina
 

Cora Lilia Alvarez^1*, Mariela Pamela Azcarate², Laura Terminiello³,
Daniel Cabral⁴, Graciela Vaamonde⁴, Virginia Fernández Pinto^1
1Prhideb-Proplame Conicet, Departamento De Biodiversidad Y.Biologia Experimental, Facultad De Ciencias Exactas Y Naturales, Uba Ciudad Universitaria, Pabellon Ii, 4º Piso. C1428 Eha, Buenos Aires, (ARGENTINA)
²EEA “Guillermo Covas” INTA Ruta 5Km 580, C.C.: 11(6326) Anguil, La Pampa, (ARGENTINA)
³Facultad de Ciencias Agrarias y Forestales, Universidad Nacional de La Plata,
Buenos Aires, (ARGENTINA)

Fusarium head Blight(FHB) is an important disease affecting the production of wheat worldwide, causes economic losses due to reduction in seed quality and presence of mycotoxins. The objective of the present work was to determine genotypic diversity and toxin production profile of Fusarium graminearum 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.graminearum were studied, which formed 32 Mycelial Compatibility Groups(MCGs); 12 out of 32 were multimembers groups. Nitrate non utilizing mutants were obtained from 34 isolates, which ones analyzed by VC, formed 28 Vegetative Compatibility Groups(VCGs) with 4 multimembers VCGs. The variability index was 0.82 for VC and 0.64 for MC. Forty-four out of 50 isolates produced Deoxynivalenol(DON)(0.19 to 2169.3g g^-1). The co-occurrence of DON- and Nivalenol(NIV) was detected in 27 isolates, with NIV levels between 0.1 and 14.3µg g^-1. Simultaneous production of DON and both acetyl derivatives were found in 27 isolates; DON, NIV and 15 acetyl DON were co-produced by 27 isolates, being these two the most frequent mycotoxin production profile. There was found that 41.67% of the multimember MCGs shared a similar toxin production profile. These results suggest a high diversity in the F.graminearum population from Argentinean wheat that should be taken into account to design better control strategies for FHB and suitable methods to analyse toxin contents in food and feed.