Abstract

BIAZIO, Gleison Ricardo de; LEITE, Gabriela Guimarães Sousa; TESSMANN, Dauri José  and  BARBOSA-TESSMANN, Ione Parra. A new PCR approach for the identification of Fusarium graminearum. Braz. J. Microbiol. [online]. 2008, vol.39, n.3, pp. 554-560. ISSN 1517-8382.  http://dx.doi.org/10.1590/S1517-83822008000300028.

The main objective of this work was to develop a PCR protocol for the identification of Fusarium graminearum, based on a pair of primers targeted to a segment of the 3' coding region of the gaoA gene that codes for the enzyme galactose oxidase (GO). This region has low homology with the same region of GO genes from other fungi. Genomic DNA from 17 strains of Fusarium spp. isolated from diseased cereals, from several other Fusarium species, and from other fungi genera was analyzed in a PCR assay using this primer set. The 17 strains of Fusarium spp. were also analyzed for the GO enzyme production in submerse fermentation in a new formulated liquid medium. All strains that were morphologically and molecularly identified as F. graminearum were able to secrete the enzyme and had a positive result in the used PCR protocol. No DNA fragment was amplified using genomic DNA from other Fusarium species and species of other fungi genera. The results suggest that the proposed PCR protocol is specific and can be considered as a new molecular tool for the identification of F. graminearum. In addition, the new formulated medium is a cheap alternative for screening for GO screening production by F. graminearum.

Keywords : Fusarium graminearum; galactose oxidase; gaoA gene; molecular identification.