Genetic diversity in F. graminearum from a major wheat producing region of Argentina

ALVAREZ, CL, SOMMA, S., PROCTOR, R., STEA, G., MULE, G., LOGRIECO, A., FERNÁNDEZ PINTO,V.,MORETTI, A,

TOXINS REVIEW

MDPI

Lugar: Basel; Año: 2011 vol. 3 p. 1294 - 1309

GENETIC DIVERSITY IN FUSARIUM GRAMINEARUM FROM THE MAJOR WHEAT-PRODUCING REGION OF ARGENTINA     C. L. ALVAREZ1, S. SOMMA2, R.H. PROCTOR, G. STEA2, G. MULÈ2, A.F. LOGRIECO2, V. FERNANDEZ PINTO1 and A. MORETTI2.   1Departamento de Biodiversidad y Biología Experimental, Universidad de Buenos Aires, Buenos Aires, Argentina; 2Institute of Sciences of Food Production, CNR, Via Amendola 122/0, 70126 Bari, Italy. Fax: +39.080.5929374; E-mail: antonio.moretti@ispa.cnr.it.         Correspondence: Antonio Moretti. E-mail: antonio.moretti@ispa.cnr.it     Abstract   Fusarium graminearum is a toxigenic fungal species and the primary cause of Fusarium Head Blight of wheat worldwide. Recent DNA sequence-based phylogenetic analyses have resolved the fungus into multiple species, which are collectively known as the F. graminearum species complex (FGSC). One hundred-eighty-three field isolates of Fusarium recovered from wheat in Argentina were examined from the major wheat-producing region of Argentina (Buenos Aires Province).  Sequence analysis of genes encoding translation elongation factor 1-a and β-tubulin and Amplified Fragment Length Polymorphism (AFLP) analysis indicated that all isolates were F. graminearum sensu stricto. The AFLP analysis also indicated that all the isolates were highly similar to one another (similarity coefficient > 0.84).  None of the isolates had the same haplotype, and there was no correspondence between AFLP profile and geographical origin. One hundred-seventy nine out of 183 isolates had a genetic-based marker indicative of production of deoxynivalenol (DON) and none had the marker indicative of nivalenol production. One hundred and seven isolates also had the genetic marker indicative of 15-acetyldeoxynivalenol (15ADON) production, and none had the genetic marker indicative of 3-acetyldeoxynivalenol (3ADON) production. Genetic chemotyping revealed the predominance of the DON-15ADON genetic chemotype in F. graminearum in Argentina. This genetic chemotype was mainly found in subregion IIS (65%) and it was found in lesser frequencies in subregions IV and VS (51 and 50%, respectively). Genetic chemotyping showed agreement with metabolite profiling obtained previously. These data provide further evidence that F. graminearum sensu stricto is the predominant cause of FHB in wheat-growing regions of Argentina and suggests that, although the FGSC is homogenous with respect to species in Argentinean wheat fields, the genetic diversity detected within F. graminearum sensu stricto poses serious problems for developing strategies for disease management and plant breeding.    Keywords: Fusarium Head Blight; AFLP, translation elongation factor 1-a; β-tubulin; deoxynivalenol; 3-acetyldeoxynivalenol; 15-acetyldeoxynivalenol.   GENETIC DIVERSITY IN FUSARIUM GRAMINEARUM FROM THE MAJOR WHEAT-PRODUCING REGION OF ARGENTINA     C. L. ALVAREZ1, S. SOMMA2, R.H. PROCTOR, G. STEA2, G. MULÈ2, A.F. LOGRIECO2, V. FERNANDEZ PINTO1 and A. MORETTI2.   1Departamento de Biodiversidad y Biología Experimental, Universidad de Buenos Aires, Buenos Aires, Argentina; 2Institute of Sciences of Food Production, CNR, Via Amendola 122/0, 70126 Bari, Italy. Fax: +39.080.5929374; E-mail: antonio.moretti@ispa.cnr.it.         Correspondence: Antonio Moretti. E-mail: antonio.moretti@ispa.cnr.it     Abstract   Fusarium graminearum is a toxigenic fungal species and the primary cause of Fusarium Head Blight of wheat worldwide. Recent DNA sequence-based phylogenetic analyses have resolved the fungus into multiple species, which are collectively known as the F. graminearum species complex (FGSC). One hundred-eighty-three field isolates of Fusarium recovered from wheat in Argentina were examined from the major wheat-producing region of Argentina (Buenos Aires Province).  Sequence analysis of genes encoding translation elongation factor 1-a and β-tubulin and Amplified Fragment Length Polymorphism (AFLP) analysis indicated that all isolates were F. graminearum sensu stricto. The AFLP analysis also indicated that all the isolates were highly similar to one another (similarity coefficient > 0.84).  None of the isolates had the same haplotype, and there was no correspondence between AFLP profile and geographical origin. One hundred-seventy nine out of 183 isolates had a genetic-based marker indicative of production of deoxynivalenol (DON) and none had the marker indicative of nivalenol production. One hundred and seven isolates also had the genetic marker indicative of 15-acetyldeoxynivalenol (15ADON) production, and none had the genetic marker indicative of 3-acetyldeoxynivalenol (3ADON) production. Genetic chemotyping revealed the predominance of the DON-15ADON genetic chemotype in F. graminearum in Argentina. This genetic chemotype was mainly found in subregion IIS (65%) and it was found in lesser frequencies in subregions IV and VS (51 and 50%, respectively). Genetic chemotyping showed agreement with metabolite profiling obtained previously. These data provide further evidence that F. graminearum sensu stricto is the predominant cause of FHB in wheat-growing regions of Argentina and suggests that, although the FGSC is homogenous with respect to species in Argentinean wheat fields, the genetic diversity detected within F. graminearum sensu stricto poses serious problems for developing strategies for disease management and plant breeding.    Keywords: Fusarium Head Blight; AFLP, translation elongation factor 1-a; β-tubulin; deoxynivalenol; 3-acetyldeoxynivalenol; 15-acetyldeoxynivalenol.