Member discussion regarding the methods, varieties and merits of growing tomatoes.
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January 5, 2016 | #1 |
Tomatovillian™
Join Date: Feb 2010
Location: Indiana
Posts: 1,124
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Gold and orange tomato genetics
I'm sure that I've read that gold and orange tomatoes result from recessive traits. So if that is true, then the only way that you could have an orange F1 is if both parents carry the recessive trait. (?) And if you plant the seeds of the (orange) F1, then the gold/orange trait should be expressed in what percent of the offspring? At least 75%? Or am I not looking at this correctly... My question results from wanting to plant the seeds from some Orange F1's, hoping to get an orange F2.
-GG |
January 5, 2016 | #2 |
Tomatovillian™
Join Date: Mar 2011
Location: Raleigh, NC
Posts: 1,448
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See: http://frogsleapfarm.blogspot.com/20...-color-in.html
and http://the-biologist-is-in.blogspot....-tomatoes.html
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Blog: chriskafer.wordpress.com Ignorance more frequently begets knowledge: it is those who know little, and not those who know much, who so positively assert that this or that problem will never be solved by science. --Charles Darwin Last edited by ChrisK; January 5, 2016 at 06:11 PM. |
January 5, 2016 | #3 |
Tomatovillian™
Join Date: Dec 2010
Location: Sunol, CA
Posts: 2,723
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As someone who has done some work with gold/orange varieties, my impression is that there are many reasons that the genetics of these colors complicated, and not simply summarized into rules about dominance.
1. There are many pigments potentially involved in what we perceive as gold or orange (for example, small amounts of pink lycopene combined with yellow pigments can make a fruit appear "orange".) 2. There are many genetic modifiers that affect pigment pathways, and what may appear as a simple dominant/recessive trait in one cross may be less clear in another cross. With regard to your question as to whether seed from an orange F1 will produce orange-fruited F2 plants -- the most likely answers are Yes. All of the F2 might be orange fruited. Particularly if both parents of the hybrid were orange. Yes. Some of the F2 fruit are likely to be orange. However, these plants may also be hybrid for the orange-governing genes, and the orange color may be difficult, if not impossible to stabilize (because stabilization is the result of gradually losing traits that are dependent on heterozygosity). |
January 5, 2016 | #4 |
Tomatovillian™
Join Date: Jun 2012
Location: Illinois, zone 6
Posts: 8,407
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Isn't there a tangerine gene that is recessive and also a dominant orange gene in a few varieties like Podarok Fei and Juanne Flamme?
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January 5, 2016 | #5 |
Tomatovillian™
Join Date: Feb 2012
Location: Newfoundland, Canada
Posts: 6,794
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tangerine is recessive, and it is only expressed when tt homozygous.
tangerine tt is expressed in both yellow and red background fruit. It is not an allele of the basic red/yellow colour gene. It is yellow-orange in a yellow and darker orange in a red background. Beta is a dominant gene, partly expressed in heterozygous condition but only in red/red background not in a yellow fruit. The Beta/- F1 is orange-red so this isn't the case of the op, unless the orange fruit turn red after you leave them to ripen a longer time. An orange F1 from either tangerine or Beta would have to have both parents with either tt or BB. They are not allelic to each other either - a t and a B won't produce orange if crossed. So.. if the orange colour is due either to tangerine or due to Beta, the F2 would all be orange. But as Fred pointed out, there are yet other genetics besides these that produce orange fruit. |
January 6, 2016 | #6 |
Tomatovillian™
Join Date: Feb 2010
Location: Indiana
Posts: 1,124
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Thanks for the replies and links. Those links are especially thorough!
@bower -- I'm curious about growing tomatoes in Newfoundland. Is it very difficult to grow tomatoes in Newfoundland with (I presume) a ocean-driven climate? I looked at the average temps, and summer was a mean of 18/9 for the June-August months. But on the flip-side -- probably not much need of air conditioning! -GG Last edited by Greatgardens; January 6, 2016 at 09:26 AM. |
January 6, 2016 | #7 | |
Tomatovillian™
Join Date: Feb 2012
Location: Newfoundland, Canada
Posts: 6,794
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Quote:
Selection of varieties is limited - no point in growing anything "late" as the season isn't long enough. Also varieties that don't start to produce unless daytime highs are over 70 are pretty much losers or a 'rare treat'. But luckily tomatoes are diverse enough that quite a few are happy to grow and set between 60-70 F days. Our summer weather is also really variable. Climate change has opposite effects on our weather from year to year, either hotter or colder than normal. We had great summers 2012, 2013 and hottest July on record in 2014, followed by coldest on record in 2015. Greenland ice is melting and cooling the water around us. Icebergs in summer make it really chilly. Certain weather patterns over greenland also make it pretty bad here sometimes for weeks on end of drizzle and fog. The first year I started growing heirlooms was 2011 - a really bad summer. Only 3 of 10 varieties tried produced any fruit. In the greenhouse. This is what got me interested in breeding tomatoes, and also collecting and trialing as many OP's/heirlooms as I can find that are better suited. Eastern European and Russian varieties overall have been the best here. My mom even grows some of them outdoors, but in a year like this past one she got only a late harvest of green fruit to ripen off the vine (they were good, mind you!). Farmers here pretty much use greenhouses, as the yield of ripe fruit even from the best suited varieties is much less outdoors, and scanty if it's a bad year. |
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January 7, 2016 | #8 | |
Tomatovillian™
Join Date: Jun 2012
Location: Minnesota
Posts: 586
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Quote:
There is always the chance for peculiar behavior in genetics, so it is best not to get too attached to what the "official" story says.
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http://the-biologist-is-in.blogspot.com |
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January 7, 2016 | #9 |
Tomatovillian™
Join Date: Feb 2006
Location: Alabama
Posts: 2,250
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We had quite a discussion of the carotenoid biopath in Crosstalk a few months ago. It would be worth your time to read the posts since they break down some items that are useful in understanding ripening genetics.
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January 7, 2016 | #10 | |
Tomatovillian™
Join Date: Jan 2011
Location: S.E. Wisconsin Zone 5b
Posts: 1,831
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Quote:
Dutch
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"Discretion is the better part of valor" Charles Churchill The intuitive mind is a gift, and the rational mind is a faithful servant. But we have created a society that honors the servant and has forgotten the gift. (paraphrased) Albert Einstein I come from a long line of sod busters, spanning back several centuries. |
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November 4, 2016 | #11 |
Tomatovillian™
Join Date: Jun 2006
Location: central NJ z6/7
Posts: 73
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Sorry to bring back this old thread. I have become interested in tetra-cis-lycopene (prolycopene) and beta-carotene rich tomatoes because of the presumed health benefits.
Took me a while to find the thread that Fusion_power was refering to: http://www.tomatoville.com/showthrea...ne+gene&page=7 Lots of cool stuff there! There is a recent publication that provides detailed carotenoid composition of six heirloom tomatoes: ‘Kellogg’s Breakfast’ , ‘Yellow Brandywine Platfoot Strain’, ‘Cherokee Purple’, ‘German Johnson Regular Leaf ’, ‘Aunt Ruby’s German Green’ and ‘Black from Tula’. http://www.omicsonline.com/open-acce...4784#Full-Text Not surprisingly, Kellog's Breakfast is super high in prolycopene. More interestingly, Black from Tula has the highest beta-carotene and lutein content of the six tomato varieties. I am curious what is the genetics of bicolor tomatoes, let's say Lucky Cross. Is it predominantly tangerine with only weak activity of CrtISO in some parts of the fruit? |
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