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Old July 11, 2013   #11
crmauch
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Join Date: May 2013
Location: Honey Brook, PA Zone 6b
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Quote:
Originally Posted by tlintx View Post
Interesting, so you'd basically be looking for the orangest, most carrot-colored (or reddest, for lycopene) tomato you could get. In that case, could you use a digital camera plus color balance strip to make photos to compare to other attempts? Maybe use the one you referred to earlier and a carrot as reference points?
I would have thought this too, however in doing online 'research' I've found that not all orange tomatoes are created equal. Anything in the 'yellow' to white (often noted as r) reduces all carotenoids.

There is an 'Apricot' gene (noted as at) that seems to show a very slight increase in beta-carotene.

There is a 'tangerine' gene (noted as t) that has reduced beta- and and increase in something called zeta-carotene (and other different carotenoids

And there is Del which has 'normal' beta but much increase delta-carotenoid (I can find information about beta (of course) and have found out that alpha carotenoid is considered 'half' as effective for conversion to vitamin A, but there doesn't appear to be any information on whether delta-carotenoid can be converted to vitamin A in the body.

The article about breeding these is here: http://www.genetics.org/content/62/4/769.full.pdf

There is another article about breeding with B (high beta-carotene) and Del here:
http://www.genetics.org/content/56/2/227.full.pdf

However there doesn't appear to be articles about breeding these newer very high carotene tomatoes with both B and MOG [the G should be subscripted] and how they interact with the other 'orange' genes. An article about the USDA introduction of breeding stock with these high carotene genes notes that B (which is dominant) and the dominant form of the linked modifier gene MOG+ reduces beta-carotene from 90% of the carotenoids to 50-60% and increases lycopene to less than 50% giving red-orange tomatoes. That article is here: http://hortsci.ashspublications.org/...2/387.full.pdf

The 'safest' way (it seems to me) to preserve high beta would be to breed the high betas only to red (or pink) varieties, and select them back to orange.
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