Location: Sunflower Improvement Research
Project Number: 3060-21220-034-032-S
Project Type: Non-Assistance Cooperative Agreement
Start Date: Aug 15, 2024
End Date: Dec 31, 2025
Objective:
The research aims to identify and evaluate effective BCAs from diverse environments, particularly the Northern Great Plains. This region, with its varied cropping systems and recent surge in soybean production, presents a unique opportunity for BCA research. Two main objectives of this proposal include the follow. 1) Cataloging and evaluating microbes from soil and rhizosphere in crops susceptible to S. sclerotiorum. 2) Evaluating the effectiveness of commercial BCAs in controlling Sclerotinia stem rot of soybean in replicated field trials.
Approach:
This project will leverage access to canola, pulses, dry beans, sunflowers, soybeans, and other cops to begin isolating highly diverse microbes for the establishment of a set of microbial collections that can be used extensively for the identification of BCAs, the establishment of diversity studies, and the creation of future synthetic communities which may serve as a viable option for long-term biological control within individual fields. Objective 1 will catalog and evaluate potential biological control agents (BCAs) from diverse cropping systems in the Northern Great Plains, with a particular focus on North Dakota. In conjunction with a soil survey currently funded by the North Dakota Soybean Council, soil samples will be collected from fields across North Dakota, encompassing a variety of crops like sunflower, pulses, dry beans, canola, and soybean. Special attention will be given to fields showing signs of Sclerotinia stem rot infection. Sampling will occur at multiple growth stages, from seedling to full maturity, over two years. In instances of Sclerotinia stem rot outbreaks, samples from the rhizosphere of unaffected plants will be carefully taken, ensuring minimal disturbance.
The collected soil and rhizosphere samples will undergo serial dilution procedures and then be plated onto growth media such as potato dextrose agar (PDA) or nutrient agar (NA). This step aims to promote the growth of a diverse range of microorganisms. Each bacterial and fungal colony that develops will be isolated, meticulously cataloged, and placed into long-term storage in glycerol solution at -80°C until future evaluation. Biological control evaluation will be accomplished using a series of dual culture, detached leaf assays, and production and testing of cell-free filtrates. Each of these assays will follow an RCBD, replicated four times, and repeated at least once. This will be followed by genomic and metabolomic analysis, including genetic sequencing and metabolomics conducted with GC-MS analysis. Identified BCAs will be applied and evaluated in greenhouse trials. Objective 2 will be a field trial will evaluate the efficacy of six commercial biological control products against S. sclerotiorum in soybeans. Disease development and yield will be assessed at two locations in Eastern North Dakota, both of which have natural populations of S. sclerotiorum. Yield data will be collected at the end of the season, in 3 successive years. Additionally, sub-samples of harvested grain will be examined to determine the level of sclerotia production. Environmental conditions, including temperature, humidity, and rainfall, will be recorded using on-site stations from the North Dakota Agricultural Weather Network.
