Index, Individual Trait, and Tandem Selection to Improve a Maize Synthetic for Yield, Corn Borer, and Disease Traits
Genetic variance and covariance estimates from replicated trials of 120 to 200 half-sib families of a maize (Zea mays L.) synthetic were obtained in one to three years for grain yield (measured on uninoculated plants), quantitative resistance to four common leaf and stalk diseases evaluated separately, the aggregate effect of several common leaf and stalk diseases, and first generation European corn borer (CB) {caused by Ostrinia nubilalis (Hubner)}. These data were used to estimate genetic correlations between pairs of traits, to construct two selection indexes designed to improve the synthetic for yield and resistance to CB and common Illinois maize diseases simultaneously, to predict gain from selection, and to determine adequate numbers of replicates and plants per plot for half-sib and S(,(PERP)) family selection for each disease trait. Two sequential cycles of divergent selection for the indexes were completed and compared with one cycle of tandem selection which involved high intensity mass selection for aggregate leaf and stalk rot resistance, followed by recombination and half-sib family selection for yield. One cycle of divergent half-sib family selection for each trait per se was also completed and evaluated.
Agriculture, Agronomy, Agriculture, Plant Pathology
University of Illinois - Urbana-Champaign
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University of Illinois at Urbana-Champaign