Location: Soybean and Nitrogen Fixation Research
Project Number: 6070-21220-070-028-R
Project Type: Reimbursable Cooperative Agreement
Start Date: Oct 1, 2022
End Date: Sep 30, 2023
Objective:
Overcoming the devastation of drought is a cornerstone of sustainable soybean production. Several recent major droughts across the US stress the need for building better long-term drought resilience. Drought is no longer considered a localized problem to certain regions of the US, but a significant problem that can affect farmers anywhere in the US. Drought stress can not only reduce yield, but also seed composition. If drought conditions occur during the reproductive stage of soybean, pods and seed can be smaller and fewer than normal, with poorer quality attributes. Farmers need drought risk mitigation strategies. The most economical and sustainable alternative to irrigation is new drought-tolerant soybean varieties.
Objectives to which ARS investigator will contribute:
1). Evaluate commercial varieties for drought tolerance and yield in maturity groups (MG) V through VIII.
2). Develop and evaluate new drought-tolerant breeding stock for potential release, so that commercial breeding programs can develop better drought-tolerant varieties.
3). Develop novel breeding lines which combine drought tolerance with high oleic oil and high protein meal.
Approach:
Objective 1: Commercial varieties will be selected in conjunction with the local North Carolina Official Variety Testing (OVT) Program and private breeders. In 2023, 116 commercial varieties will be evaluated at the Sandhills Research Station in NC. The Sandhills Research Station has deep, sandy soils which provides a unique opportunity to investigate plants under drought stress. Commercial lines will be evaluated using a randomized complete block design with four replications. Known fast wilting and slow wilting lines will be included as checks. All lines will be evaluated for visual wilting scores and yield to determine the level of drought tolerance. Wilting scores will be recorded on a scale of 1-5, with 1 being no damage and 5 being severe wilting and plant damage.
Objective 2: Advanced breeding lines will be evaluated for yield performance and drought tolerance in replicated drought tests at the Sandhills Research Station in 2023. Evaluation will include more than 50 new lines derived from 2 wild soybean accessions, retesting of more than 40 new USDA breeding lines derived from previously identified drought tolerant breeding stock and retesting of an additional 50 USDA breeding lines which have exhibited drought tolerance in previous years. Lines will be evaluated in a similar approach to objective 1.
Objective 3: New breeding lines will be developed using conventional breeding methods to combine drought tolerance with high oleic oil and high protein meal. Hybrid seed will be developed in the summer of 2023 from more than 10 unique drought tolerance x high oleic oil and drought tolerance x high protein meal crosses and hybrid (F1) plants will be grown in the USDA winter nursery in Puerto Rico in the winter of 2023-2024.
