What is the difference genetically between these two?

[mastiffsinky]

What is the difference (would prefer the genotypes) between a black tailed buff and a buff columbian? and is a buff without any black on it absent of the columbian gene?

 

[blackdotte]

Black tailed Buff are Wheaten ,Gold,Autosomal Red,Dilute and either Columbian or Dark Brown. The lighter coloured birds are Columbian. Adding Mahogany to the above gives the orange coloured New Hampshire. Adding Melanotic to the Columbian option gives the Buff Columbian.
David

 

[Henk69]

The columbian gene helps buff, it is not the gene that produces the black hackle markings on an all buff bird.

Columbian with wheaten should have the least hackle black, with e^b brown the most (eg wyandotte).

But other genes can enhance "columbian" markings eg in the wheaten-based light sussex, or in the brown-based lakenvelder. Genes like charcoal and melanotic Ml.

In my experience columbia gene = Co does not make a paler gold color, but it reduces red leakage in silver birds.

The Db gene is a columbian like restrictor that also reduces the hackle markings a bit extra.
It does not equalize the red/gold groundcolor as much as columbia = Co does.

Columbian like restrictors are the genes that remove the black breast and body pattern from the chicken.

The genes that remove the black tail are largely unknown.

 

[Henk69]