<em>Fusarium oxysporum</em> f. sp. <em>papaveris</em>: a new forma specialis isolated from iceland poppy (<em>Papaver nudicaule</em>)

Abstract

Symptoms of a new vascular wilt were observed on several plants of Papaver nudicaule cultivated at the Regional Institute for Floriculture in Sanremo and in a nursery near Ventimiglia, Liguria region, Northern Italy. Morphology and ITS sequence analysis characterize the pathogen as Fusarium oxysporum. To identify the forma specialis, eight isolates obtained from infected tissues were used for a phylogenetic analysis based on translation elongation factor 1-α (EF-1α) gene and four polygalacturonase genes (Pg1, Pg5, Pgx1 and Pgx4). After amplification by PCR, the gene sequences were aligned with corresponding sequences from other formae speciales of Fusarium oxysporum obtained from GenBank databases in order to build phylogenetic trees. Results obtained for each genomic region showed that the isolates derived from P. nudicaule form a unique group well separated from other formae speciales. To our knowledge, this is the first report of F. oxysporum on P. nudicaule and together with the phylogenetic analysis and positive pathogenicity tests permits us to introduce a new forma specialis named F. oxysporum f. sp. papaveris.

Keywords

• Fusarium
• EF-1α
• endopolygalacturonase