ARS | Publication request: PATHOGENICITY AND STABILITY OF A TAGGED FUNGAL WEED PATHOGEN

Submitted to: National American Phytopathology Meetings
Publication Type: Abstract Only
Publication Acceptance Date: April 20, 1997
Publication Date: N/A

Technical Abstract: The release of microbes for biological control of weeds requires the unambiguous identification of the released pathogen. We have transformed F. oxysporum f.sp. erythroxylii, a pathogen of Erythroxylum coca, with a plasmid construct conferring hygromycin resistance, to test the effect of the introduction of marker sequences on stability and pathogenicity. Transformed clones were analyzed for hygromycin resistance, and the stability of single-spored progeny on hygromycin also was quantitated. One clone, pHRC-1k demonstrating a high level of resistance to hygromycin, was selected for further study. Southern blot analyses confirmed integration of the DNA elements into the pHRC-1 genome. Microconidia were propagated for inoculation of Erythroxylum plants in root dip bioassays to establish the pathogenicity of the transformant. The transformant took longer to achieve the same rate of kill as the wild-type. Transformants recovered from killed Erythroxylum plants on Fusarium-selective media maintained resistance to hygromycin, indicating the stability of the integrated gene.