Fusarium oxysporum f. sp. passiflorae infecting passionfruit in New Zealand in a changing taxonomic landscape

Fusarium oxysporum f. sp. passiflorae (FOP) is reported for the first time in Northland, New Zealand. The identity of this host-specific pathogen was confirmed by pathogenicity testing, morphological characters, and DNA sequencing. Pathogenic strains of Fusarium oxysporum secrete unique proteins or effectors, ‘secreted in xylem’ ( SIX ), which are likely to contribute to host-specific virulence. Sequence analysis of the EF-1a gene, β-tubulin and the effector genes SIX6 and SIX9 confirmed that New Zealand isolates belong to FOP. This study confirmed that the three New Zealand EF-1α haplotypes of FOP had identical SIX6 and SIX9 sequences, indicating that the same homolog of each gene, SIX6a and SIX9a , is shared by both haplotypes of FOP. SIX genes are rarely detected in non-pathogenic strains of Fusarium oxysporum species complex (FOSC) and pathogenicity tests are necessary to confirm its pathogenicity status.