Genetics of Violet Factor

Summary:
Violet Factor - semi-dominant
Normal - recessive

There are only two alleles for the violet trait: the violet factor gene and the normal gene. The violet factor gene is semi-dominant to the recessive normal gene. Because it is semi-dominant, in some cases a single-factor violet looks different from a double-factor violet. Here, we will represent the violet gene as "V" and the normal gene as "v". Therefore there are three possible genetic combinations for any budgie:

• vv - Two normal genes (homozygous) resulting in a normal budgie.
• Vv - One violet factor gene and one normal gene (heterozygous) resulting in a violet budgie only in cobalts and slightly detectable violet undertones in greens, sky blues, and mauves.
• VV - Two violet factor genes (homozygous) resulting in a violet budgie in cobalts and sky blues and detectable violet undertones in greens and mauves.

As you can see, the presence of one violet factor causes violet coloration in a budgie, but only causes true violet body color in cobalt budgies (budgies with one dark factor). Two violet factors cause the violet coloration in budgies to be more visible, but only causes true violet body color in cobalts and sky blues. It is difficult to breed true violets because of the conditions required to obtain the true violet body color. You can usually tell a green budgie has at least one violet factor. The violet darkens the green body color and sometimes causes violet to show in the feathers near the feet and vent. The feet may also look very dark or purple. Single-factor violet sky blues are darker that normal sky blues and usually show some violet coloration on the body feathers near the feet and vent. It is very difficult to tell if a mauve has the violet factor. Below are some punnet square examples of pairings.