Direct Method of Calculating Quadratic Expression from Phenotypic Classes

An equation for obtaining the quadratic expression from the phenotypic classes is developed. It is expressed in terms of p² as

Where α, β, θ, γ are the numerical values of the first term of the four phenotypic classes and α’ is numerical value of the second term in each class. This quadratic expression is useful in calculating the linkage value from F₂ data.