Backcross

Backcross (Bc) refers to mating of heterozygous F1 generation individual with the homozygous parental generation individual. In the presence of complete dominance (A > a), the following genotypic and phenotypic ratios can be found in the Bc generation:

Monohybridism (single locus / gene, two alleles)
Bc – Monohybridism :


 * Aa x AA

Genotype ratio: 1 (AA) : 1 (Aa)

Phenotype ratio: uniform




 * Aa x aa

Genotype ratio: 1 (Aa) : 1 (aa)

Phenotype ratio: 1 (Aa) : 1 (aa)



Dihybridism (two loci / genes with two alleles each)
Bc – Dihybridism :


 * AaBb x AABB

Genotype ratio': 1 (AABB) : 1 (AABb) : 1 (AaBB) : 1 (AaBb)

Phenotype ratio: uniform




 * AaBb x aabb

Genotype ratio: 1 (AaBb) : 1 (Aabb) : 1 (aaBb) : 1 (aabb)

Phenotype ratio: 1 : 1 : 1 : 1



Related articles
Homozygote

Heterozygote