Location: Vegetable Research
Project Number: 6080-30400-033-001-S
Project Type: Non-Assistance Cooperative Agreement
Start Date: Jun 1, 2026
End Date: May 31, 2031
Objective:
1. Develop and identify sweetpotato germplasm resistant to Meloidogyne enterolobii (Me) through screening seedling selections in a nematode infested field.
2. Evaluate yield and quality of M. enterolobii resistant sweetpotato selections under field conditions.
3. Publicly release new sweetpotato cultivars or breeding lines with resistance to M. enterolobii.
Approach:
Identification of M. enterolobii resistant sweetpotato germplasm.
We have identified sources of Meloidogyne enterolobii (Me) resistance in sweetpotato germplasm and using the resistant material as parents in breeding nurseries to develop new sweetpotato germplasm that has a combination of resistance to soil-dwelling insect and root-knot nematode pests of sweetpotato. Up to 5,000 seedlings will be germinated and grown by Cooperator and 2-3% will be jointly selected by ARS and Cooperator based on high yield, skin and flesh color, and insect resistance. The selected seedlings will be tested for resistance to Me by Cooperator and for resistance to insects at the USDA, ARS, U.S. Vegetable Laboratory (USVL; Charleston, SC) in the year after initial selection. This breeding and selection cycle will be repeated each year for the duration of the agreement.
Evaluation of yield and quality of sweetpotato breeding selections grown in a Me infested field.
Seedling selections that meet the specified criteria in objective 1 will be grown in replicated field trials by Cooperator and ARS to identify germplasm that is resistant to Me and soil-dwelling insect pests. Me resistance will be assessed by Cooperator and insect resistance will be assessed by ARS. Sweetpotato selections that have yield, nematode resistance, and insect resistance equal to or higher than the widely grown sweetpotato cultivars Beauregard and Covington will be evaluated in additional seasons and prioritized for public release as cultivar(s) or breeding line(s). Yield will be assessed based on the USDA sweetpotato grades. Each year 20% of the germplasm will be retained and the cycle repeated throughout the duration of this agreement.