Root Infection and Minituber Yield Response to Powdery Scab in Plant Growth Chamber Conditions

This is the authors' abstract. We don't add key points for this paper.

Powdery scab, caused by the soilborne plasmodiophorid Spongospora subterranea f. sp. subterranea ( Sss), is an increasing concern. Developing potato varieties with enduring resistance is crucial for sustainable disease management. However, the lack of a consistent infection assay for Sss has hindered effective evaluation of disease symptoms, including root gall formation and tuber lesions. This study introduces a reliable method for assessing Sss pathogenicity using a sand/potting mixture in a controlled-environment plant growth chamber. Potato plants were inoculated with three types of inocula sourced from root galls, infested soil, and scab-like tube lesions. All inocula successfully induced root galls and tuber lesions, with the tuber lesion-derived inoculum producing the highest number of root galls and tuber lesions. Additionally, the method demonstrated a marked impact of the disease on tuber yield, weight, and size in both highly susceptible and moderately susceptible cultivars. These findings underscore the efficacy of this infection assay as a robust tool for evaluating Sss pathogenicity. This method holds promise for screening potato germplasm to develop resistant varieties against powdery scab. [Formula: see text]