Genetics - Color

[Fabian24]

I have a plant of Cattleya wallisii (syn C. eldorado) with these light colored flowers.



If I make a selfing of this plant, is it possible to get some plants with flowers of a darker color?

Thanks!

[orchidsarefun]

Ideally you should know/discover the parentage of yours. If one ( or both ) parents was a darker colour, your's may be an alba selection of that cross - or even an alba clone. Selfing should give you a representation of both parents. If however yours is for example a 10th generation alba, then maybe your selfing won't result in many ( or any ) with a darker colour bloom as the gene for the darker colour has been bred out.
With seedlings anything is possible - I would go ahead and self it to see the results. I have a paph lowii in flask and based on what the breeder told me I should get a sampling of albas because the one parent is an alba though the selfing wasn't.
I am no geneticist but the above is my understanding of how things work. Of course I am open to learning any new stuff if anyone has a more informed view.

[Fabian24]

Thank you!!
I don't know the parentage of mine. I bought it as a seedling with no info about the cross they did.

One of my first orchids was a C trianae seedling which was a cross of two alba forms, and the flowers turned to be purple. At that time I read about genetics of the alba forms: the gene C that makes the plant produce chromogen and the gene R responsible of the production of the enzyme that converts the chromogen into anthocyanins (that make the flowers haver color).
I mean, for instance, ccRR and CCrr are 2 alba forms but if you cross them you will get 100% colored flowers.

But this C wallisii, is not an alba form. It has very light purple tones (specially in the lip). I think they call it forma amesiana in Brazil.
Half an hour ago, I searched a little bit and found an article (see below) that states that very lightly colored flowers have another allele: that of dilution D. (D: dense coloration, d: diluted)
So, if that article is correct, the genetical constitution of a plant like mine should be:

ddCcRr (or other, but always starting with dd)

So it seems that I can't get stronger coloured flowers after all... I will always have dd in the selfings.

Article: Breeding Cattleya Tribe Orchids