Pathogenicity Differentiation of spp. Causing Fusarium Basal Rot and Wilt Disease in spp.

Here, 12 strains, previously described as . f. sp. (), were examined via multi-locus sequencing of calmodulin (), RNA polymerase II second largest subunit (), and translation elongation factor 1-alpha (), to verify the taxonomic position of in the newly established epitype of . . The strains in this study were divided into two clades: . and sp. To further determine the host specifications of the strains, inoculation tests were performed on onion bulbs and Welsh onion seedlings as potential hosts. Four strains (AC145, AP117, Ru-13, and TA) isolated from diseased onions commonly possessed the ()-, , , , , , and genes and were pathogenic and highly aggressive to onion bulbs, whereas all strains except for one strain (AF97) caused significant inhibition of Welsh onion growth. The inoculation test also revealed that the strains harboring the gene were highly aggressive to both onion and Welsh onion and the gene was expressed during infection of both onions and Welsh onions, suggesting the important role of the gene in pathogenicity. This study provides insights into the evolutionary pathogenicity differentiation of strains causing Fusarium basal rot and wilt diseases in species.