|Cramer, Robert - COLORADO STATE UNIVERSITY|
|Byrne, Patrick - COLORADO STATE UNIVERSITY|
|Brick, Mark - COLORADO STATE UNIVERSITY|
|Schwartz, Howard - COLORADO STATE UNIVERSITY|
Submitted to: Journal of Phytopathology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: April 5, 2003
Publication Date: June 3, 2003
Citation: CRAMER, R.A., BYRNE, P.F., BRICK, M.A., PANELLA, L.W., WICKLIFFE, E.R., SCHWARTZ, H.F. CHARACTERIZATION OF FUSARIUM OXYSPORUM ISOLATES FROM COMMON BEAN AND SUGAR BEET USIG PATHOGENICITY ASSAYS AND RANDOM AMPLIFIED POLYMORPHIC DNA MARKERS.. JOURNAL OF PHYTOPATHOLOGY. 2003. Interpretive Summary: Interpretive summary Fusarium wilt is an economically important fungal disease of common bean and Fusarium yellows of sugar beet in the Central High Plains (CHP) region of the United States. Losses due to these diseases approach 30% of the crop under appropriate environmental conditions. The objective of this study was to determine how closely related the strains of fungus obtained from common bean and sugar beet plants were in the CHP. A technique using the fungal DNA was used (RAPD analysis) to measure the relationships. Only 4 of the 166 strains collected from common bean caused disease in common bean. A set of 20 of the 166 strains including the 4 that caused disease were chosen for analyses. Ten strains of the fungus which caused disease on sugar beet were included in the analyses. The 4 strains obtained from the CHP appeared identical in our analyses but the analyses separated those strains from common bean that caused disease from the strains that caused no disease and from the strains that came from sugar beet.
Technical Abstract: Technical Abstract. Fusarium wilt is an economically important fungal disease of common bean and Fusarium yellows of sugar beet in the Central High Plains (CHP) region of the United States with yield losses approaching 30% under appropriate environmental conditions. The objective of this study was to characterize genetic diversity and pathogenicity of isolates of Fusarium oxysporum obtained from common bean and sugar beet plants in the CHP that exhibited Fusarium wilt symptoms using random amplified polymorphic DNA (RAPD) markers and pathogenicity assays. One hundred and sixty-six isolates of F. oxysporum isolated from diseased common bean plants in the CHP were screened for pathogenicity on the universal susceptible common bean cultivar `UI 114.' Only 4 of the 166 collected isolates were pathogenic and were designated F. oxysporum f.sp. phaseoli (Fop). A set of 20 F. oxysporum isolates including the 4 collected Fop isolates and samples from races 1, 3, 4 and 6 were chosen for RAPD analysis. Ten isolates of F. oxysporum f.sp. betae (Fob) from sugar beet and one isolate of Fusarium solani also were included in the RAPD analysis. Twelve RAPD primers generating 105 polymorphic bands were selected to construct unweighted paired group method with arithmetic averages (UPGMA) dendrograms based on Jaccard's coefficient of similarity. Identical RAPD banding patterns were observed for the 4 Fop isolates obtained from the CHP and for the race 1 and 4 isolates. RAPD markers distinguished Fop races 1 and 4 from races 3 and 6, and Fop isolates from all non-pathogenic (Fo) and Fob isolates.