A group of identical individuals that are bred for many generation from members of the same strain and always produce progeny of the same phenotype when selfed or intercrossed. Cf breeding line.
Mendel used individuals in the first (P1) generation.
P1 yellow X green ...
He mated a variety that was pure-breeding (hence homozygous) for round (RR), yellow (YY) seeds with one that was pure-breeding for wrinkled (rr), green (yy) seeds.
Mendel crossed (also referred to as true-breeding) smooth-seeded plants with a variety that had always produced wrinkled seeds (60 fertilizations on 15 plants). All resulting seeds were smooth.
The term which Mendel (1866) proposed for a character which was not evident in the first filial generation (F1) of a cross between two pure-breeding strains differing in respect of this character, ...
A group of identical diploid or polyploid organisms, distinguished from other individuals of the same species by some unique phenotype and genotype.
He crossed pure-breeding peloric plants with pure breeding wild types, noting the dominance of the wild type in the F1 progeny.
See also: Breed, Character, Strain, Organ, Dominant