Location: Sunflower Improvement Research
Project Number: 3060-21220-034-030-S
Project Type: Non-Assistance Cooperative Agreement
Start Date: May 20, 2024
End Date: May 19, 2025
Objective:
This project will contribute to genetic improvement of sunflower resistance to Sclerotinia head rot, a major disease that limits sunflower production in the North Central Great Plains where most US sunflower production is concentrated. Major objectives of this project will be to: (1) Develop new sunflower germplasm resources with novel and/or improved Sclerotinia head rot resistance in agronomically acceptable germplasm for release to the public; (2) Evaluate an advanced backcross genetic mapping population for Sclerotinia head rot resistance over multiple years in inoculated field nurseries to facilitate mapping of disease resistance quantitative trait loci (QTL) introgressed from the wild sunflower species Helianthus nuttallii; (3) Support the mission of Grand Farm through participation in outreach and engagement with stakeholders and the public and by working to incorporate new technologies such as remote sensing and detection into future research on Sclerotinia head rot resistance and management.
Specific goals for this project period are to: (1) Evaluate testcross hybrids and advanced breeding materials for Sclerotinia head rot response (~500 rows) to determine performance of new, potentially resistant inbred lines when utilized for hybrid production, to evaluate newly developed lines for prospective public release, and to collect data for development of genomic selection models; (2) Support Grand Farm efforts toward stakeholder and public engagement and outreach.
Approach:
Inoculated disease nurseries will be established annually to evaluate experimental sunflower materials for resistance to Sclerotinia head rot. Head rot nurseries will be planted in plots with overhead mist irrigation and plants will be inoculated by spraying with a Sclerotinia sclerotiorum ascospore suspension during bloom. Inoculated plants will be scored for disease using a standardized disease rating scale prior to plant maturity. Disease incidence and severity data will be evaluated using appropriate statistical methods and will be used to inform future crosses to advance breeding efforts, to make determinations about potential public release of new genetic resources, and to map genetic loci contributing to Sclerotinia head rot resistance. These disease evaluations must be conducted at research sites with irrigation facilities.
