| Fumonisins produced by Fusarium verticillioides ( syn = F. moniliforme) and F. proliferatum have been associated with potentially serious toxicoses of animals and humans. Thus, hybrids with low fumonisin accumulation in grain will be valuable for the production of corn-based human food products. Corn hybrids with naturally occurring genetic resistance to Fusarium ear rot and with very low or no fumonisin in grain offer the most cost effective, environmentally friendly and publicly acceptable method of controlling fumonisin in corn-based food products. The objectives of this study were to determine the types and magnitudes of gene action associated with resistance to fumonisin accumulation in grain and Fusarium ear rot using the inbreds TBA76125, CG1, CQ201 or GE440 as sources of resistance crossed with the susceptible inbred FR1064. Other objectives were to determine heritabilities, predicted gain from selection and usefulness for resistance to fumonisin accumulation in grain and severity of Fusarium ear rot in segregating populations and to develop phenotypic data on a large number of backcross to the susceptible selfed families that could be used for molecular marker analysis and the future identification of quantitative trait loci associated with resistance to fumonisin accumulation in grain and severity of Fusarium ear rot. The resistant inbred TBA76125 was considered the best source of resistance. The inbred TBA76125 and the F1 generation were low for both fumonisin concentration and Fusarium ear rot. The inbreds CG1, CQ201 and GE440 all had higher fumonisin concentrations and Fusarium ear rot than TBA76125. The F1 generation from CG1, CQ201 and GE440 all had similar fumonisin concentrations and Fusarium ear rot as the TBA76125 F1 generation. Usefulness was also the lowest for the TBA76125 BCP2S1 population. The usefulness statistic takes into account both the mean of the population and the expected gain from selection. Overall, the TBA76125 population had the lowest mean for both fumonisin concentration and Fusarium ear rot. All of the populations had similar expected gains from selection, heritabilities and correlations. The inbreds TBA76125, CG1, CQ201 and GE440 all could contribute genes for resistance to fumonisin concentration and Fusarium ear rot. |
