Link to home

Cross Pathogenicity and Vegetative Compatibility of Fusarium oxysporum Isolated from Sugar Beet

September 2013 , Volume 97 , Number  9
Pages  1,200 - 1,206

Kimberly M. Webb, United States Department of Agriculture–Agricultural Research Service, Sugar Beet Research Unit, Ft. Collins, CO 80526; and Austin J. Case and Mark A. Brick, Department of Soil and Crop Sciences, and Kris Otto and Howard F. Schwartz, Department of Bioagricultural Sciences and Pest Management, Colorado State University, Ft. Collins 80523

Go to article:
Accepted for publication 21 March 2013.

Fusarium oxysporum f. sp. betae causes Fusarium yellows in sugar beet (Beta vulgaris). The F. oxysporum population from sugar beet can be highly variable in virulence and morphology and many isolates are nonpathogenic. Rapid and reliable methods to identify pathogenic isolates from nonpathogenic F. oxysporum generally are unavailable. Little is known about nonpathogenic isolates, including the role they may play in population diversity or virulence to sugar beet. Sugar beet is often grown in rotation with other crops, including dry edible bean (Phaseolus vulgaris) and onion (Allium cepa), with F. oxysporum able to cause disease on all three crops. Thirty-eight F. oxysporum isolates were collected from symptomatic sugar beet throughout the United States to investigate diversity of the F. oxysporum population and the influence of crop rotation on pathogenic variation. These isolates were characterized for pathogenicity to sugar beet, dry edible bean, and onion, as well as vegetative compatibility. Pathogenicity testing indicated that some F. oxysporum isolates from sugar beet may cause disease on onion and dry edible bean. Furthermore, vegetative compatibility testing supported previous reports that F. oxysporum f. sp. betae is polyphyletic and that pathogenic isolates cannot be differentiated from nonpathogenic F. oxysporum using vegetative compatibility.

This article is in the public domain and not copyrightable. It may be freely reprinted with customary crediting of the source. The American Phytopathological Society, 2013.