Author
Yates, Ida | |
SPARKS, DARRELL - HORT/UGA, ATHENS, GA |
Submitted to: Aflatoxin Elimination Workshop Proceedings
Publication Type: Abstract Only Publication Acceptance Date: 10/16/2006 Publication Date: 10/16/2006 Citation: Yates, I.E., Sparks, D. 2006. Migration of Fusarium verticillioides between inoculated and non-inoculated ears of field-grown corn plants. Aflatoxin/Fumonisin Elimination/Fungal Genomics Workshop Proceedings. October 16-18, 2006. Ft. Worth, TX. Interpretive Summary: Abstract - no summary necessary. Technical Abstract: Consequences of Fusarium verticillioides colonization of corn kernels may be plant disease and/or mycotoxin production. Plant disease may reduce crop production and mycotoxins may cause harmful, and often fatal, effects on humans and animals. Understanding migration patterns of F. verticillioides among corn plants is essential for developing strategies to prevent diseases of corn plants and eliminate mycotoxins from our food chain. The purpose of the current research was to analyze the field dissemination of F. verticillioides from corn ears inoculated with F. verticillioides PATg, a transformant with a selection gene, hph, for hygromycin resistance (hygr) and a reporter gene, gusA, coding for ß-glucuronidase (GUS). Corn ears were inoculated through either the shuck or the silk channel at two stages of development, green silks and brown silks. The average expression of hygr was 66% and GUS was 96% for mycelia emerging from kernels of ears inoculated with F. verticillioides. Mycelia resistant to hygromycin appeared in cultures of kernels from non-inoculated and water-inoculated ears, but only at <3%. However, none of the mycelia stained positive for GUS in kernels originating from non-inoculated ears and only 7% of those isolated from kernels of water-inoculated ears. Thus, dissemination of F. verticillioides PATg was minimal from plant to plant under field conditions existing in Georgia during the growing seasons of 2001, 2002, and 2003. The only slight evidence of dissemination occurred in a few ears inoculated with water through the silk during the green silk stage of development. Perhaps, the mechanical injury during inoculation provided an entry site for the spores of F. verticillioides PATg dispersed by abiotic factors, such as rain or wind. |