Corn Breeding: Introduction to Concepts in Quantitative Genetics Glossary

The deliberate mating of two parental types of organisms in genetic analysis.

(deoxyribonucleic acid) The molecule that encodes genetic information. DNA is a double-stranded molecule held together by weak bonds between base pairs of nucleotides. It is the fundamental substance of which genes are composed.

The combinations of all the conditions external to the genome that potentially affect gene expression and the phenotype of a plant.

The fundamental unit of heredity that carries genetic information from one generation to the next. A gene is an ordered sequence of nucleotides located on a particular position on a particular chromosome that encodes a specific functional protein.

The fundamental unit of heredity that carries genetic information from one generation to the next. A gene is an ordered sequence of nucleotides located on a particular position on a particular chromosome that encodes a specific functional protein.

The allelic composition of a cell or organism.

The allelic composition of cells or organisms.

The proportion of observed variability which is due to heredity (genetics), the remainder being due to environmental causes. More strictly, the proportion of observed variability due to the additive effects of genes.

An individual produced by crossing two parents of different genotypes.

The observable physical characteristics of an organism that are determined by a combination of the genetic composition (genotype) and the environment of the individual.

A large molecule composed of one or more chains of amino acids in a specific order. Proteins are necessary for the structure, function, and regulation of an organism's cells, tissues, and organs. Each protein has a unique function determined by its shape.

A natural or artificial process that favors or induces survival and perpetuation of one kind of organism over others that die or fail to produce offspring.

The characteristic that results from an expressing gene(s). Ex. Upright leaves, drought tolerance, Bt resistance. A trait can be influenced by the environment.

Crop plants within a species that have the same genetic composition. Because plants in a self-pollinated crop are usually homozygous, the variety and their offspring will remain genetically pure (i.e., barley varieties).  Because plants in a cross-pollinated crop are usually heterozygous, the variety and their offspring will not remain genetically pure (i.e., hybrid corn varieties).