Table 1.

Genotype probabilities, genotype means, and variance attributable to a segregating locus as a function of genetic model and cross type

		Probability
Genotype	Mean	F2	BCA	BCB	RIL
AA	μ + α −δ/2	¼	½	0	½
AB	μ + δ/2	½	½	½	0
BB	μ − α −δ/2	¼	0	½	½
		Variance attributable to locus
Model	Parameter	F2	BCA	BCB	RIL
General		¼ δ2+ ½ α2	¼ (α + δ)2	¼ (α + δ)2	α2
No dominance	δ = 0	½ α2	¼ α2	¼ α2	α2
A dominant	δ = α	3/2 α2	0	α2	α2
B dominant	δ = −α	3/2 α2	α2	0	α2
No additive	α = 0	¼ δ2	¼ δ2	¼ δ2	0

F₂ = intercross; BC_A = backcross to the A strain; BC_B = backcross to the B strain; and RIL = recombinant inbred lines.