Plant-fungus interactions, molecular biology and evolution of toxigenic Fusarium species and biological control

 

We are developing and using molecular detection and quantification methods for different fungal species including Fusarium and Aspergillus species and fungi used in biological control. The molecular data is also used for taxonomical and phylogenetic investigations and to determine, which mycotoxins are correlated with the DNA levels of different plant pathogenic fungi.

Background

Fusarium species are the most economically important phytopathogenic and mycotoxigenic genus of filamentous fungi in cereals. Several Fusarium species are involved in Fusarium head blight (FHB), which reduces both crop yield and quality in cereals by toxins dangerous for humans and animals. In the EU maximum limit values for the first Fusarium toxins have already been determined for deoxynivalenol (DON) and zearalenone (ZEN) and in the near future they will be determined for HT-2 and T-2 mycotoxins. In Finland the highest levels of DON and HT-2/T-2 have been found in oats, which is an important crop for human food and animal feed.  F. graminearum is the most important Fusarium species. In addition, we are investigating Aspergillus species, which are producing aflatoxins and entomopathogenic fung, whichi can be used in biological control of mites and insects.

Research

We are monitoring the genetic variation, distribution and quantification of plant-pathogenic F. graminearum and F. langsethiae isolates from different host plants  and the new Asian species F. sibiricum in Finland and Russia by molecular methods The project also aims to obtain non-pathogenic mutants of F. langsethiae  in order to evaluate their mycotoxin production and interactions with the host plants.  These studies combined with the available F. graminearum genome sequence will facilitate the understanding of the host-pathogen interactions and facilitate design of new strategies to control FHB.  We are also investigating toxigenic Aspergillus isolates and the phylogeny of these and entomopathogenic  fungal species.used in biological al control.

Significance

Fusarium species are among the most economically important phytopathogenic and mycotoxigenic filamentous fungi in cereals. They reduces yield quantity and quality and mycotoxins produced by Fusarium species are harmful to humans and animals. The available F. graminearum genome sequence will give new possibilities to investigate plan-fungus interactions. We are also investigating F. graminearum chemotypes and populations in order to find out, if they are specific to different geographical areas and host plants. Aspergillus flavus and A. parasiticus are important producers of aflatoxins.  Entomopathogenic fungi are used in biological control against mites and pest insects.