True-breeding

Definition

Two organisms that are described as true-breeding for a trait, when crossed, will always produce offspring with exactly the same genotype as them for that trait. This means true-breeding organmisms are homozygous for the true-breeding trait, It is important to remember that this applies both dominant or recessive traits.

Hartl D.L, Ruvolo M, (2011) Genetics analysis of genes and genomes, 8th edition:Jones and Bartlett Publishers, Inc.