Skip to main content
ARS Home » Midwest Area » Peoria, Illinois » National Center for Agricultural Utilization Research » Mycotoxin Prevention and Applied Microbiology Research » Research » Publications at this Location » Publication #283853
Title: Fusarium torreyae sp. nov., a pathogen causing canker disease of Florida torreya (Torreya taxifolia), a critically endangered conifer restricted to northern Florida and southwestern Georgia

Author
item AOKI, TAKAYUKI - National Institute Of Agrobiological Sciences (NIAS)
item SMITH, JASON - University Of Florida
item MOUNT, LACEY - Dellavalle Laboratory, Inc
item GEISER, DAVID - Pennsylvania State University
item O Donnell, Kerry

Submitted to: Mycologia
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 9/17/2014
Publication Date: 3/1/2013
Citation: Aoki, T., Smith, J.A., Mount, L.L., Geiser, D.M., O'Donnell, K. 2013. Fusarium torreyae sp. nov., a pathogen causing canker disease of Florida torreya (Torreya taxifolia), a critically endangered conifer restricted to northern Florida and southwestern Georgia. Mycologia. 105(2):312-319.

Interpretive Summary: Florida torreya (Torreya taxifolia) is a critically endangered evergreen tree threatened by extinction. With fewer than 1000 individuals in the wild, the range of this conifer is restricted to northern Florida and southwestern Georgia. During a survey for pathogens of this tree conducted in northern Florida in 2009, most of the Florida torreya surveyed exhibited localized, discolored areas on the stems called cankers. When putative pathogens isolated from the cankers were characterized by DNA typing, a novel species of the filamentous mold Fusarium was discovered. This unnamed Fusarium was shown to be the causal agent of the Florida torreya canker disease in a pathogenicity experiment because it induced cankers when inoculated onto healthy individuals of this conifer. To facilitate communication within the plant pathology community, the Florida torreya pathogen was formally described as the novel species, Fusarium torreya, based on morphological and DNA data. This study will be of interest to plant disease specialists, quarantine officials, and conservation biologists because it contains information on the current distribution and morphology of this pathogen and it provides DNA data crucial for its detection and identification. In addition, plant breeders interested in developing cultivars of Florida torreya with broad based resistance to this pathogen will benefit from the information reported in this study.

Technical Abstract: During a survey for pathogens of Florida torreya (Torreya taxifolia) conducted in 2009, a novel Fusarium species was isolated from cankers affecting this critically endangered conifer whose current range is restricted to northern Florida and southwestern Georgia. Published multilocus molecular phylogenetic analyses indicated that this pathogen represented a genealogically exclusive, phylogenetically distinct species representing one of the earliest divergences within the Gibberella clade of Fusarium (Smith et al. 2011). Furthermore, completion of Koch’s postulates established that this novel species was the causal agent of Florida torreya canker disease. Here, we formally describe this pathogen as a new species, Fusarium torreyae. Pure cultures of this species produced long and slender multiseptate sporodochial conidia that showed morphological convergence with two distantly related fusaria, reflecting the homoplasious nature of Fusarium conidial morphology.