Archivio Journal of Plant Pathology

Abstract:

Fusarium oxysporum has recently been detected in commercial nurseries in the Ligurian region (northern Italy) on new succulent plants belonging to the Cactaceae family (Astrophytum myriostigma, Cereus marginatus var. cristata, C. peruvianus monstruosus and C. peruvianus florida) and to the Euphorbiaceae family (Euphorbia mammillaris). The pathogen has been identified, for all the new hosts, from morphological characteristics observed in vitro. The identifications have been confirmed by means of ITS (Internal Transcribed Spacer) analysis and/or by Translation Elongation Factor 1α (TEF) analysis. The aim of this work was to identify the forma specialis of the F. oxysporum isolates obtained from new succulent plants. This has been investigated by means of phylogenetic analysis based on the TEF gene and intergenic spacer (IGS), carried out on single-spore isolates, together with pathogenicity assays. The results of this research led to include four new succulent hosts from Cactaceae as additional hosts to F. oxysporum f. sp. opuntiarum. This forma specialis has been identified for the first time on a new host (Euphorbia mammillaris) not belonging to the Cactaceae family.