A Possible Method for Locating Favorable Genes in Maize

Abstract

Present-day methods of corn improvement involve the isolation of inbred lines through self-fertilization and selection. These inbred strains are subsequently intercrossed and some, though not all, hybrid combinations are superior in vigor to the open-pollinated varieties from which the inbred lines were derived. Practically all crosses are greatly superior to the vigor of the inbred parents. The theoretical foundations for the increased vigor obtained by these empirical methods have never been completely established. The assumption is that open-pollinated varieties of corn are heterozygous for many pairs of genes, the recessive alleles of which have in general less favorable effects upon viability and vigor than their dominant alleles. Different varieties and different individuals of the same variety may carry different recessive genes.

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