Identification of Fusarium Species Associated With Dry Rot of Potato Tubers in Sinaloa, Mexico

Northern Sinaloa is one of the most important potato-producing regions in Mexico. Potato dry rot caused by species of Fusarium is one of the major threats to potato production. The aim of this study was to identify and characterize Fusarium species associated with potato dry rot. A total of 146 Fusarium isolates were obtained from potato tubers with dry rot symptoms from fields in different geographic regions in northern Sinaloa, Mexico, in 2018–2019. A subgroup of 39 representative isolates was selected for further morphological and molecular characterization as well as pathogenicity tests. According to morphological features and phylogenetic analyses of the transcription elongation factor 1-α (EF1-α) gene, the isolates were identified as F. oxysporum clade 3, F. falciforme (FSSC 3 + 4) and F. nygamai. All representative Fusarium species isolates were pathogenic to potato tubers. Furthermore, a significant difference in virulence between species was observed. Future research should focus on understanding the genetic diversity and population structure of these pathogens in the field.