4.6 The Violet Factor
The violet gene (V) is another incomplete dominant gene that affects the birds in a manner similar to the dark factor gene. We had discussed that a dark gene affects the appearance of a bird as if you were looking at the bird through dark sunglasses. The effect of the violet factor can be thought of as looking at the bird through violet sunglasses. A green bird with a single violet gene V+/V will show a violet sheen on the green body. Two violet genes (DF) will cause a bird to appear darker than a Violet green Single Factor bird.
A blue bird with a single violet gene bl/bl V/V will show a light violet blue color, Two copies of the violet gene V/V will show a rich violet color on a blue bird.
The violet gene has the most striking effect when it is present along with a copy of the dark gene on a blue bird. This bird is called a cobalt violet or commonly a visual violet. DF violet blues and DF Violet cobalts are also known as visual violets. The following table shows the various combinations of the Dark and Violet genes. The highlighted combinations are the visual violets. These birds show a rich violet color.
Let us look at an example
Cobalt X Violet Blue
bl/bl, D+/D, V+/V+ X bl/bl, D+/D+, V+/V
Now there are three genes that we have to work with, Blue Violet and dark
Fortunately, we note that the bl/bl genes are common in both birds. We can therefore drop it from our Punnett square diagram as all offspring will have bl/bl genes.
The Cobalt can contribute D+ and V+ or D and V+. The Violet Blue can give D+ and V+ or D+ and V. A Punnett square diagram will look like this
[attachment=0:1tx3hbd2]4.6 Cobal X Violet Blue.JPG[/attachment:1tx3hbd2]
From the diagram we get
25% Sky Blue
25% Violet Blue
25% Violet Cobalt
Try this one
Mauve X Violet Cobalt