An emerging pathogen of potato found by UMN researchers will require vigilant crop monitoring.
A first report made by Ranjan Lab members confirms that fungal pathogen Verticillium dahliae race 3 has been discovered in Minnesota. V. dahliae variants are one of the main causes of Verticillium wilt of potato, a yield-limiting crop disease already troubling Midwestern farmers.
In 2022, lab member Kay Lerohl and PI Ashish Ranjan began working in a Sherburne County, MN disease nursery field with the goal of screening potato crops for Verticillium wilt disease resistance. During the 2022–2023 period, they observed Verticillium wilt symptoms in more than 80% of potato plants grown in this experimental disease nursery. In 2023, the team further characterized isolated fungal samples at the molecular level to identify the species and race of Verticillium present. Using genomic DNA isolation and PCR amplification of the effector gene and sequencing, the research team, now also including Josephine Le Winkel, was able to confirm that race 3 of V. dahliae was growing in Sherburne County, which was previously not reported in Minnesota. More information on their process, and confirming Koch's postulates, can be found in the full publication.
Minnesotan farmers, gardeners, and professionals in extension and education should be aware of Verticillium wilt and its symptoms, especially in the absence of resistant potato cultivars. (See the image below or the linked video.) Genetic pathogen information such as this report, though, should provide valuable information to plant pathologists and breeders developing disease management strategies and resistant varieties. Findings underscore the evolving threat of soilborne pathogens and the critical role of adaptive agricultural strategies.