Molecular characterization of Fusarium oxysporum f.sp. cichorii pathogenic on chicory (Cichorium intybus)

Abstract

Fusarium oxysporum is a ubiquitous soilborne ascomycete responsible for vascular wilt in many plant species worldwide. This species comprises more than 120 putative host-specific formae speciales capable of causing remarkable economical losses. In summer 2009, wilt symptoms, including chlorosis and poor development of the root system were observed on cultivars of chicory (Cichorium intybus) in northern Italy. The causal agent isolated from symptomatic tissues in this case was identified as F. oxysporum on the basis of both morphological features and molecular analyses. In this work, we attempted to characterize the isolates of F. oxysporum from C. intybus by both biological and molecular approaches. Pathogenicity trials performed on 5 species of the Asteraceae family with isolates of F. oxysporum from C. intybus indicated that the pathogen has a unique host range, infecting chicory only. Neither lettuce nor endive, lawn daisy and Paris daisy developed the disease. Five cultivars within C. intybus species were tested, and the cv Clio was the most susceptible. Phylogenetic analyses relative to the ribosomal intergenic spacer (IGS) and translation elongation factor 1-alpha (EF1-) assigned isolates pathogenic to chicory to a single cluster, distinct from other pathogenic F. oxysporum. In light of these views, we propose to designate this organism as Fusarium oxysporum f.sp. cichorii.

Epitypification of Fusarium oxysporum – clearing the taxonomic chaos

“…W.C. Snyder & H.N. Hansen, 1999, Katan & Di Primo 2010, Chakrabarti et al 2011, Poli et al 2012, Amer. J. Bot.…”

“…1940, b, Jiménez-Gasco & 2004a, b, Jiménez-Gasco & Jiménez-Díaz 2003, Fusarium lateritium f. ciceri (Padwick) Jiménez-Díaz 2003, Sharma et al 2004, 2014, Honnareddy & Dubey Erwin, Phytopathology 48: 500. 1958Sharma et al 2004, Honnareddy & 2006, Bayraktar et al 2008, Dubey & Singh 2008, Dubey 2006, Gurjar et al 2009, Gurjar et al 2009, Dubey et al 2012 Dubey et al 2012, Demers et al 2014, 2014, Ghosh et al 2015, Upasani et al 2016, Williams Upasani et al 2016 cichorii Poli et al 2012Poli et al 2012 citri…”

Identification and Characterization of the Antifungal Substances of a Novel Streptomyces cavourensis NA4

“…sp.) that exhibit high host specificity [9]. It is a devastating pathogen that affects many important food and vegetable crops and is a major source of loss to farmers worldwide.…”

Genetic diversity and virulence of Italian strains of Fusarium oxysporum isolated from Eustoma grandiflorum

“…Among the genes used for phylogenetic studies (e.g. intergenic spacer (IGS) rDNA, elongation factor-1α, polygalacturonases, mitochondrial small subunit ribosomal RNA, phosphate permease, β-tubulin, nitrate reductase, MAT1 and MAT2), the EF-1α (Poli et al 2012) and polygalacturonases genes (Hirano and Arie 2009) seem to be the most appropriate for application to the Fusarium genus (O'Donnell et al 2009;Srinivasan et al 2012). In particular, polygalacturonases are the major secreted cell-wall-degrading enzymes in plant pathogenic fungi.…”