Integrated management of wheat fusarium head blight
Executive Summary
Wheat Spike Fusarium (WST) reduces production and causes toxicological problems in humans and animals. Due to the higher corn-wheat rotation and stubble cover the incidence of WST has increased in the Southern Cone. The project aimed to develop WST control strategies, based on genetic resistance and cultural practices. Germplasm evaluation showed that some commercial varieties have resistance to WST and that regional ancestral wheat and synthetic wheat may be other sources of resistance for new varieties. A collection of 118 cultivars with varying degrees of resistance to Fusarium was used for molecular characterization. A fluorometric method was used to quantify the Fusarium mycotoxin DON and to identify germplasm with good correlation between the percentage of affected grains and the DON content. Material derived from synthetic hexaploid wheat showed low DON contents and this trait seems to be associated with resistance to the pathogen. WST was found to be associated, at different frequencies, with different Fusarium species. The variability of Fusarium isolates was determined by molecular markers, confirming the co-existence of very virulent variants with low virulent ones. Regarding control practices, a limited effect of sowing date and nitrogen fertilization was observed, while the use of fungicides is more effective.
The technological solution
This was a basic research project that did not generate technologies for immediate field application but information related to wheat germplasm resistance to Fusarium and methodologies for characterization of the resistance and Fusarium pathogenicity and mycotoxin production. The benefits of the work are manifested in wheat breeding programs in the region that can use the information generated.
Results
Cultivars and advanced lines of wheat of regional origin and hexaploid lines derived from synthetic wheat were characterized according to their relationship to FET. Methodologies were defined and standardized for a more efficient selection of FET-resistant germplasm. A breeding program was initiated to combine FET resistance factors in selected varieties from the region. A fluorometric technique for the determination of the main mycotoxin produced by F. graminearum was validated and advanced lines of breeding programs associated with the presence of this mycotoxin were evaluated. The study of the pathogenic variability of the predominant Fusarium species in the region was initiated. Interactions between planting dates, stubble management, fertilization and chemical control and disease control were identified.
Beneficiaries
The direct beneficiaries are the researchers and breeders of the participating institutions and other regional bodies who are working to solve one of the problems with the greatest impact on the agrifood chain and who will make use of the information on wheat varieties and lines with different degrees of resistance to the disease produced by Fusarium in the breeding programmes. They will also make use of the analytical methodologies validated by the project. In the long term, the beneficiaries will be the farmers who adopt the resistant commercial varieties that breeders may produce based on the information generated by this project.
Sustainable Development Goals
Participating Organizations
Executor
- Instituto Nacional de Tecnología Agropecuaria (INTA) - Argentina
Associated
- Empresa Brasileña de Investigación Agropecuaria (EMBRAPA) - Brasil
- Instituto Nacional de Investigación Agropecuaria (INIA) - Uruguay
- DIA - MAG - Paraguay
- INIFAP - México
- Centro Internacional de Mejoramiento de Maíz y Trio (CIMMYT) - México