Database Research Summaries2018 Disease Management Equals Higher Yields
Research Focus
The focus of this project is to identify the best disease management practices for Ohio’s challenging environments and changing pathogen populations.
Objectives
- Evaluate germplasm for baseline levels of soybean disease resistance to Phytophthora sojae, Sclerotinia sclerotiorum, Fusarium virguliforme (SDS), Fusarium graminearum, Cercospora sojina,Pythium irregulare, Pythium ultimum, and other Pythium spp.
- Monitor the emergence and changing sensitivity of pathogens to common fungicides used in Ohio that cause frogeye leaf spot and Pythium seedling blight.
- Identify mechanisms of genetic change in the primary soybean pathogen of Ohio, P. sojae, and evaluate the genetic and pathogenic diversity of Py. irregulare and Py. ultimum collected in Ohio.
- Characterize the resistance identified in both cultivated and Korean PIs towards P. sojae, Pythium spp., and Fusarium graminearum-Identify quantitative trait loci (QTLs) and mechanisms associated with partial resistance.
- Identify best management practices that limit the impact of soybeans diseases for Ohio including Sclerotinia stem rot, SCN, charcoal rot, Phytophthora sojae, SDS, and Pythiumseedling diseases.
Results
- 399 lines were screened in 5 different populations for resistance (Rps genes, quantitative resistance or both to P. sojae and are now beginning new populations from the harvest this year.
- We received only 8 samples of frogeye leaf spot from 6 counties during the summer of 2018 and more are still in process. All of the samples received had the marker for the most common mutation for resistance to strobilurin fungicides. These results will impact the recommendations for farmers in Ohio that have frogeye to focus on other fungicides with a different mode-of-action.
- DNA was collected from soil samples to assess diversity using a microbiome approach and this analysis is ongoing. These isolates will be used in these studies that assess genetic change within Ohio populations.
- All 950-soil samples from Ohio, Indiana, and Kentucky have been baited at least once. Currently, 538 isolates of Phytophthora sojae were recovered from 950 soil samples collected from Ohio, Indiana, and Kentucky- approximately 50% of the 538 isolates have been pathotyped to determine which and if any of the current Rps genes would be effective.
- Studies for new chemistries for seed treatments to control, Fusarium, Rhizoctonia and watermolds (Pythium and Phytophthora); foliar fungicides for frogeye leaf spot; and flowering applications for Sclerotinia appear to be very successful this year.
Importance
- This research will be used to develop and deploy new varieties with high levels of disease resistance, which will ultimately increase yield and soybean quality.
- This research will support the development of soybeans with resistance to key plant pathogens (Phytophthora sojae, Pythium spp., Fusarium virguliforme, Fusarium graminearumand Cercospora sojina) for Ohio and identify genes, which may be deemed as specialty traits that can be released as licensed germplasm.
For more information about this research project, please visit the National Soybean Checkoff Research Database.
Funded in part by the soybean checkoff.
