Phenotypic Screening and Statistical Validation of an Evaluation Scale for Fusarium Dry Rot Resistance in Potato Germplasm

Abstract

Potato is a globally important staple, but postharvest diseases such as dry rot, caused by Fusarium spp., threaten production and lead to major economic losses and food safety risks. Limited resistant cultivars highlight the need for phenotypic screening and integration with genomic tools to improve resistance and breeding efficiency. A total of 336 potato genotypes, including 295 commercial varieties and 41 breeding clones, were evaluated under post-harvest conditions following artificial inoculation. Tubers were inoculated with Fusarium sambucinum, and lesion penetration measured to classify susceptibility. Overall, this study provides one of the most comprehensive phenotypic evaluations of dry rot resistance in potato germplasm to date. While no variety was fully resistant, the identification of both moderately susceptible and highly susceptible cultivars offers valuable insights for breeding programs and contributes to the development of more resilient potato production and storage systems. In addition, this phenotypic screening can be integrated with genomic tools to accelerate breeding for improved resistance and postharvest performance.