Re: HYB: oldies - sidebar (pigment)

I will take a stab at it - I do understand this part, tho I doubt I can explain it very well:
pink (lycopene) and yellow (carotene) are both oil soluble pigments. If the right genes are present, pink pigment is produced and is converted to yellow. If not, you get pink. ("they" used to think this pigment group started out as yellow, then was converted to pink, but now it's thought to go the other way).
There is also a water soluble yellow pigment, and I <think> there is another oil soluble yellow pigment that is <not> part of the pathway from lycopene (pink and red bearded whites)to carotene (yellow, deep gold beards).
Anyway, as far as genetics are concerned, I think of both pink and yellow irises as being the same "color", but needing four doses of tttt to be pink, otherwise being yellow. So the "normal" genes "finish" turning the pink pigment yellow.
I'm sorry I can't explain this stuff very well... anyway, IMM <may> have one dose of t, & Don Spoon got a pink seedling from it (tho Lloyd thought it had to be a mixup), so it may even have two tt's. It definitely has some yellow genes or it wouldn't produce so many creams & occasional yellows in crosses with pinks. My guess is that it has 3 yellows - & I guess that gene must be recessive too. So it's Yyyy?
Cream or white is what I was expecting from the cross, maybe yellow, hoping for pink, & I'm delighted to get a nice clean yellow rebloomer for the first bloom out of the cross! Only thing better would have been a pink rebloomer. Deep gold of the beards makes me think it has enough carotene to give pink seedlings.
The part I don't know anything about is what regulates the shade of yellow (cream to deep gold)
I don't know about how many I's IMM has, or if it has 4 doses of recessive anthocyanin "white" or both. 

I hope I got most of that right.

<are there any guesses how a yellow seedling
resulted from a pedigree that appears to be weighted for pink?>

--
Linda Mann east Tennessee USA zone 7/8
East Tennessee Iris Society <http://www.DiscoverET.org/etis>
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