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ARS Home » Midwest Area » Madison, Wisconsin » Vegetable Crops Research » Research » Publications at this Location » Publication #406096
Research Project: Introgression of Disease Resistance and Tuber Quality Traits from Wild Species Relatives into Diploid Cultivated Potato

Location: Vegetable Crops Research

Title: Spongospora subterranea f. sp. subterranea affects plant susceptibility to subsequent pathogen infections under controlled-environment conditions

Author
item OZTURK, IBRAHIM - University Of Wisconsin
item BUCHHOLZ, ELIZABETH - University Of Wisconsin
item BENTLEY, ALLY - University Of Wisconsin
item Halterman, Dennis
item RIOUX, RENEE - University Of Wisconsin

Submitted to: Plant Disease
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/8/2024
Publication Date: 6/14/2024
Citation: Ozturk, I.K., Buchholz, E., Bentley, A., Halterman, D.A., Rioux, R. 2024. Spongospora subterranea f. sp. subterranea affects plant susceptibility to subsequent pathogen infections under controlled-environment conditions. Plant Disease. 108(7):2148-2153. https://doi.org/10.1094/PDIS-02-24-0276-RE.
DOI: https://doi.org/10.1094/PDIS-02-24-0276-RE

Interpretive Summary: Potato powdery scab is caused by the fungus Spongospora subterranea f. sp. subterranea (Sss) and is responsible for disfigurement of the potato tubers and decreased plant yields. This fungus also spreads the Potato mop-top virus (PMTV). Susceptibility of potato to Sss is assessed by the number of of tuber scab and root gall symptoms. We investigated the impact of Sss inoculation on disease symptom development, yield, and susceptibility to infection by other pathogens in six common potato varieties. We also determined whether potato tubers can contain the fungus even if no visible symptoms are present. We found that changes in tuber yield, disease symptoms, and plant growth rate due to Sss infection were not correlated in any of the varieties tested. Between 50% to 92% of tubers without visible powdery scab were found to contain Sss, depending on the variety. Our findings impact the process used to select the right variety for Sss management depending on grower priorities and disease pressure in the field.

Technical Abstract: Spongospora subterranea f. sp. subterranea (Sss) is a soilborne potato pathogen responsible for tuber powdery scab, root galling and dysfunction, decreased plant yields, and transmission of Potato mop-top virus (PMTV). Susceptibility to Sss is assessed by severities of tuber scab and root gall symptoms. We investigated the impacts of Sss-inoculation on disease symptom development, yield, and susceptibility to subsequent infection by Phytophthora infestans and Sclerotinia sclerotiorum in six common potato varieties. We also quantified the prevalence of asymptomatic infections in each variety evaluated. Changes in tuber yield, disease symptom incidence and severity, and plant growth rate due to Sss infection were not correlated in any of the varieties tested. Between 50% to 92% of the asymptomatic tubers were found to contain Sss, depending on the variety. Our findings highlight the importance of selecting the right variety for Sss management depending on grower priorities and disease pressure in the field.