Submitted to: Crop Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/15/2005
Publication Date: 1/26/2006
Citation: Robertson, L.A., Kleinschmidt, C.E., White, D.G., Payne, G.A., Maragos, C.M., Holland, J.B. 2006. Heritabilities and correlations of Fusarium ear rot resistance and fumonisin contamination resistance in two maize populations. Crop Science. 46:353-361. Interpretive Summary: Certain fungal pathogens of maize, including Fusarium verticillioides and F. proliferatum, cause ear rot and contaminate grain with a group of mycotoxins known as the fumonisins. In this study the correlations between fumonisin concentration, ear rot, and flowering time were examined in two populations. Results suggest that selection by plant breeders for reduced ear rot may be an effective means for producing maize lines with resistance to fumonisin contamination.
Technical Abstract: Fusarium verticillioides and F. proliferatum are fungal pathogens of maize that cause ear rot and contaminate grain with fumonisins, a family of mycotoxins that adversely affect animal and human health. Objectives of this study were to estimate heritabilities of, and genotypic and phenotypic correlations between, fumonisin concentration, ear rot, and flowering time in two populations. In the (GE440 x FR1064) x GE440 backcross population, the genotypic correlation between ear rot and fumonisin concentration was 0.96 and the phenotypic correlation was 0.40. The heritability estimate when calculated on a family mean basis was 0.75 for fumonisin contamination and 0.47 for ear rot. The correlation between fumonisin and silk date was not significant, and the correlation between ear rot and flowering time was 0.18. In the NC300 x B104 recombinant inbred line population, the genotypic correlation between ear rot and fumonisin concentration was 0.87 and the phenotypic correlation was 0.64. The heritability estimate on a family mean-basis was 0.86 for fumonisin contamination and 0.80 for ear rot. The genotypic and phenotypic correlations between fumonisin concentration and silk date were not significant, and the genotypic and phenotypic correlations between ear rot and silk date were 0.28 and 0.15, respectively. The moderate to high heritabilities and strong genetic correlations suggest that selection for reduced ear rot should be effective at producing fumonisin contamination resistant lines. Ear rot can be screened visually, and so is a less costly and time-consuming phenotype to measure than fumonisin contamination, which requires laboratory analysis of ground grain.