Submitted to: Plant Disease
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 7/17/2002
Publication Date: N/A
Citation: Interpretive Summary: Several of the fungal species that cause ear rot in maize produce a group of toxins known as the fumonisins. In order to test whether particular maize hybrids are resistant to the fungi (Fusaria) scientists need methods to inoculate them with the fungi in a controlled and predictable fashion. Four inoculation techniques were tested on 14 commercial corn hybrids in Urbana, IL. A method for inoculation through the husk leaves was selected and will be used in future experiments to evaluate a large number of maize hybrids for resistance to ear rot and fumonisin contamination. This research will benefit scientists by providing them with a tool that they can use to evaluate such hybrids.
Technical Abstract: Fumonisins have been associated with potentially serious toxicoses of animals and humans. Prior to initiating a corn (Zea mays L.) breeding program for resistance to these mycotoxins, an efficient inoculation technique must be developed. Four inoculation techniques were evaluated on 14 commercial corn hybrids in Urbana, IL in 1999 and 2000. The techniques were: injection of inoculum through the ear husk leaves at R2 (blister); silks sprayed with inoculum at R2 and covered with a shoot bag until harvest; silks sprayed with inoculum at R2, covered with a shoot bag, re-inoculated one week thereafter, and covered with a shoot bag until harvest; and insertion of Fusarium-colonized toothpicks into the silk channel at R2. Injection of inoculum through the husk leaves significantly increased the severity of Fusarium ear rot and fumonisin concentration compared to a control. This technique effectively differentiated hybrids previously identified as resistant or susceptible to Fusarium ear rot. The rank order of hybrids inoculated with this technique did not significantly change in the two years of this study. This technique is suitable for efficiently evaluating a large number of corn genotypes for resistance to Fusarium ear rot and fumonisin concentration.