Key Terms

The propagation of an individual from its somatic tissue.

A population in which one parent contributes 25% of the genes and the recurrent parent contributes 75%.

The bulk method allows natural selection to act and remove undesirable genotypes from the population.

In breeding clonal cultivars, hybridization is made between two clones. A large F1 population from the clones is screened as each F1 plant is unique and different from other F1s. This process is repeated over different crop cycles to identify the superior clone for release as a new cultivar.

A group of plants that have certain genetic, morphological, and physiological features that distinguish them from other groups of plants within a species.

Having male and female reproductive parts on separate plants.

A technique which uses electricity to separate molecule fragments according to size so they can be studied.

A crop line that has many genes for good agronomic traits that result in high yields in a particular environment.

Cultivated varieties that are well-suited to the typical environmental conditions of the target production area. These cultivars possess the necessary alleles for key traits such as end-use quality, agronomic performance, disease resistance, and regional adaptation.

The removal of male reproductive parts of a perfect flower or a monoecious plant to prevent of self-pollination.

A line developed from the cross of selected parental lines, resulting in F1 plants. The F1 plants are allowed to intermate over time to produce offspring with stable, pure-breeding lines. The pure-breeding (experimental) lines are used for evaluating specific traits, testing genetic hypotheses, and forming the basis for developing new cultivars.

An organism that has a gene copy in only one chromosome in a chromosome pair (i.e., during the transformation process, the transgene will insert into only one chromosome of a pair).

A cultivar whose plants are genetically different.

When the alleles at a locus are different.

A cultivar whose plants are genetically and phenotypically identical.

When the alleles at a locus are the same.

The process of mating closely related cultivars, or even self-fertilizing, for several generations to select for higher homozygosity.

Reduced survival and fertility of offspring from parents that are related.

Plants within a species that have the same genetic composition and are genetically pure, (i.e., inbred line). Lines are typically experimental, not agronomically competitive (hence not commercially available), and are used only in plant breeding.

Variant in the DNA sequence used as an identifier or tag of a particular aspect of phenotype and/or genotype. The inheritance of the molecular marker can be traced from generation to generation.

Having separate male and female reproductive parts in the same plant.

A breeding method used in the development of both self-pollinated (to develop pure-lines) and cross-pollinated crops (to develop inbreds).

Flowers that have both male and female reproductive parts in the same organ.

The acquisition and distribution of germplasm from one country to another.

A population in which selected plants (clones) are grown in an isolated nursery where cross-pollination occurs by wind or insect pollination.

The presence of two or more variant forms of a specific DNA sequence that can occur among different individuals or populations.

Genetically speaking, a population is a group of individuals that share a common gene pool.

Cultivars that are developed for self-pollinated species. Self-pollination leads to homozygosity and homogeneity.

A breeding method involving the selection of plants followed by intermating among the selected plants to increase the frequency of favorable alleles and decrease the frequency of unfavorable alleles in a population.

When the nucleus of a pollen grain unites with the egg cell in the ovary to produce the embryo of a seed.

The type of hybrid that is produced when two different inbreds are cross-pollinated.

A breeding method used to rapidly advance lines to homozygosity so that selection can be practiced on homozygous lines.

A population in which two parents each contribute 25% of the genes and the third parent contributes 50%.