Plant Disease (2010) 94, 31-38

M.L. Elliott, E.A. Des Jardin, K. O'Donnell, D.M. Geiser, N.A. Harrison and T.K. Broschat (2010)
Fusarium oxysporum f. sp. palmarum, a novel forma specialis causing a lethal disease of Syagrus romanzoffiana and Washingtonia robusta in Florida
Plant Disease 94 (1), 31-38
Abstract: A new disease of Syagrus romanzoffiana (queen palm) and Washingtonia robusta (Mexican fan palm) has spread across the southern half of Florida during the past 5 years. The initial foliar symptom is a one-sided chlorosis or necrosis of older leaf blades, with a distinct reddish-brown stripe along the petiole and rachis and an associated discoloration of internal tissue. Within 2 to 3 months after onset of symptoms, the entire canopy becomes desiccated and necrotic but the leaves do not droop or hang down around the trunk. Based on pathogenicity and morphological and molecular characterization, the etiological agent has been identified as a new forma specialis of Fusarium oxysporum, designated f. sp. palmarum. Sequence analysis of a portion of the translation elongation factor 1-alpha gene (EF-1alpha) separated 27 representative isolates into two EF-1alpha groups, which differed by two transition mutations. Members of both EF-1alpha groups are pathogenic on both species of palm. A phylogenetic analysis inferred from partial EF-1alpha sequences from a genetically diverse set of F. oxysporum isolates, including three other formae speciales pathogenic on palm (i.e., f. sp. albedinis, f. sp. canariensis, and f. sp. elaeidis), suggested that f. sp. palmarum and f. sp. albedinis may be more closely related to one another than either is to the two other palm pathogens.
(The abstract is excluded from the Creative Commons licence and has been copied with permission by the publisher.)
Full text of article
Database assignments for author(s): Monica L. Elliott, Nigel A. Harrison

Research topic(s) for pests/diseases/weeds:
identification/taxonomy
general biology - morphology - evolution

---

Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
	Fusarium oxysporum f.sp. palmarum	Syagrus (genus)	U.S.A. (SE)
	Fusarium oxysporum f.sp. palmarum	Washingtonia (genus)	U.S.A. (SE)
	Fusarium oxysporum