2013 Annual Report
1a.Objectives (from AD-416):
1) Evaluate the efficacy of new formulations of Fusarium head blight antagonist Cryptococcus flavescens OH 182.9 3C against FHB and DON under field conditions,.
2)characterize the biogeography and determine the diversity of C. flavescens isolated from non-inoculated wheat fields, and.
3)determine the survival and dissemination of 3C inoculant through the food system.
1b.Approach (from AD-416):
Commercially suitable formulations of Cryptococcus flavescens OH 182.9 3C will be produced by Verdesian Life Sciences from biomass of the strain supplied by the ARS collaborator. The best 4 products produced will be field tested, in the first year of studies, on a FHB susceptible and a moderately resistant cultivar by Ohio State collaborators in Wooster, OH and by the ARS collaborator in Peoria, IL. Wheat plants will be scored for FHB disease parameters and the deoxynivalenol content of grain. In a second year of field studies, results will be confirmed for superior formulations and inferior formulations substituted into a wheat field trial in each location. For objective 2, Ohio State collaborators will use a qPCR assay they developed previously to quantify the incidence and population size of C. flavescens in wheat and barley fields at multiple levels of scale. Primers derived from the sequence of the 3C genome will be used to evaluate the diversity of natural populations of C. flavescens to determine their relatedness to 3C. For objective 3, similar primers and techniques will be used to quantify natural populations of C. flavescens and strain 3C in wheat grain harvested from 3C-inoculated and non-inoculated fields.
This collaborative research project between ARS Crop Bioprotection Research Unit scientists at the National Center for Agricultural Utilization Research (NCAUR), Peoria, Illinois, and scientist at the Ohio State University (OSU) was recently initiated. The planned research will concentrate on Fusarium head blight (FHB), a devastating disease of wheat and other small grain crop that causes millions of dollars in losses in almost all major wheat-growing regions of the world. Despite substantial effort, limited success in controlling the disease has been achieved with plant breeding and the use of chemical fungicides. Cryptococcus flavescens strain 3C (a fungicide-resistant derivative of OH182.9) developed by ARS and OSU scientists, has been shown to be useful for managing FHB and reducing mycotoxin contamination of grain and is currently licensed. To facilitate the commercial launch and the required Environmental Protection Agency (EPA) registration of 3C as a biopesticide, more data are needed on the efficacy and stability of different formulations and the potential environmental and food safety risks associated with this biopesticide. ARS will conduct research to address these needs by studying the efficacy and ecology of new formulations of 3C and its natural relatives in wheat and barley fields. The proposed work will generate the data necessary to advance product development and complete EPA-mandated ecological risk assessment for this new active ingredient. To date, field trials of strain 3C tested alone as a technical grade product or formulated with either a diatomaceous earth product or one of two fungicides have been initiated in Peoria, Illinois, and Wooster, Ohio.