Semester of Graduation

Fall 2025

Degree

Master of Science (MS)

Department

Plant Pathology and Crop Physiology

Document Type

Thesis

Abstract

The reniform nematode (Rotylenchulus reniformis) is an emerging plant-parasitic threat to sweetpotato production. Dissimilar from the galling caused by root-knot nematode infections, infections from the reniform nematode occur without visible damage to the root system. In the southern United States, heavily infested sweetpotato fields can lose up to 40% of their total yield. Growers rely heavily on fumigants and nematicides which provide inconsistent control and are not sustainable in the long-term. Past research has been more focused on the efficacy of chemicals than in the identification of host resistance or tolerance in sweetpotato germplasm. This study evaluated past screening projects and streamlined a protocol that considers both nematode reproduction and sweetpotato development. Using this optimized protocol, this project screened 52 sweetpotato entries from a pool of commercial cultivars, advanced breeding lines from the LSU Sweetpotato Breeding Program, and genetically diverse germplasm from the USDA Genetic Resource Information Network (GRIN). Although no entry completely stopped reproduction of the reniform nematode, two commercial cultivars ('Vermillion' and 'Heartogold') and three GRIN plant introductions ('Regal', 'Saing-Mi', and 'Morada Sombica') supported 70-80% less reproduction than the susceptible cultivar 'Beauregard'. By creating a reproducible framework and applying it to a broad range of germplasm, this study provides a foundation for future sweetpotato breeding efforts aimed at reducing reliance on chemical nematicides and improving yield in reniform nematode infested fields.

Date

10-22-2025

Committee Chair

Watson, Tristan

Additional Files
Thesis Approval _ Tim Miller.pdf (625 kB)
Student Approval Forms
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Thesis Approval _ Tim Miller.pdf (625 kB)

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