Evaluation of Inoculation Techniques for Fusarium Ear Rot and Fumonisin Contamination of Corn

Abstract

Fumonisins have been associated with potentially serious toxicoses of animals and humans. Prior to initiating a corn (Zea mays) 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, reinoculated 1 week thereafter, and covered with a shoot bag until harvest; and insertion of six Fusarium-colonized toothpicks into the silk channel at R2. Only injection of inoculum through the husk leaves significantly increased the concentration of fumonisin in grain and severity of Fusarium ear rot compared with 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 2 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.

Impact of sowing time, hybrid and environmental conditions on the contamination of maize by emerging mycotoxins and fungal metabolites

“…The importance of flowering infection on the contamination of DON and DON-associated mycotoxins can be confirmed by considering the clear susceptibility observed in the DKC6815 cultivar, compared to the other hybrids with similar (PR32B10) or different (P1208) precocity. While the resistance sources to F. verticillioides and fumonisin accumulations are polygenic and more difficult to incorporate in hybrids (Clements et al, 2003), the genetic control of F. graminearum in maize hybrids is regulated by just a few genes and is closely linked to silk infection (Reid et al, 1994;Chungu et al, 1996).…”

Indirect selection for resistance to ear rot and leaf diseases in maize lines using biplots

“…A pipette was used to inoculate each ear with 1 mL suspension. The methodology of Clements et al (2003), with some modifications, was used in this step of the study.…”

Research Article Selection of maize inbred lines and gene expression for resistance to ear rot.

“…Inoculations of the pathogen were carried out 15 days after 100% of the plants of the plot had developed style-stigmas in the field. A pipette was used for inoculation of 1 mL of the suspension obtained, in the central region of each ear, as proposed by Clements et al (2003). The monthly mean temperatures and relative humidities of the 2011/2012 crop season are shown in Figure 1.…”