Breeding for Host Plant Resistance to FOV4 in Cotton
Abstract
Fusarium oxysporum f. sp. Vasinfectum race 4 (FOV4) is a vascular disease identified in multiple cotton producing areas in the United States. Host plant resistance (HPR) is currently the most effective control measure available to the cotton industry to combat this disease. A breeding project was initiated in 2018 by the Cotton Improvement Lab at Texas A&M University to screen germplasm and create novel breeding lines with HPR for FOV4. The program involved dual nurseries and trials in an infested field in El Paso County, TX, and a non-infested field near College Station, TX. Lines were evaluated for disease reaction, seed size, and yield components as well as fiber qualities. Analysis was conducted to determine which variables and interactions play the largest role when selecting for tolerance. Improvements have been made in the efficacy of phenotypic screening methods and trial designs since the inception of the program. In addition, measurable genetic HPR gains have been made in germplasm. As the project matured, fewer differences in resistance were found between genotypes indicating successful selection methods over the years. An incremental root stain trial conducted in 2022 gives insight on how the pathogen moves through the plant in susceptible and resistant germplasm. Based on steady improvements in both HPR to FOV4 and other agronomic qualities, it is possible to develop commercially viablecultivars for the US cotton industry.
Citation
Schultz, Alexis (2023). Breeding for Host Plant Resistance to FOV4 in Cotton. Master's thesis, Texas A&M University. Available electronically from https : / /hdl .handle .net /1969 .1 /199001.