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Old March 13, 2013   #74
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Join Date: Jan 2006
Location: Upstate NY, zone 4b/5a
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Originally Posted by GunnarSK View Post
The most famous example of an "instable" = heterozygous tomato is Green Doctors, which was found by Amy Goldman on a "Dr Carolyn" plant.

I think it was Carolyn herself who suggested, that this might be a cross rather than mutation, because a light-skinned ("clear" epidermis) variant (Green Doctors Frosted) appeared independently in three different people's growout. Now both GD and GDF are being sold by several vendors. At least Baker Creek tells honestly, that they don't sell pure Green Doctors seed, only a mix of GD and GDF. To sell "pure" = homozygous Green Doctors seed you'd have to do a growout of at least 11 plants (or more depending on required/desired confidence level) from each "mother" and bag blooms.
Gunnar, I'll try to clarify.

At the time I'd never heard of a so called white/ivory fruit, in this case Dr. Carolyn, going to a green when ripe, so I asked Keith Mueller about it and he came back and explained how it could happen, and I'm sure I still have that PM somewhere since I'm bad and tend not to delete them.

And that white to green or green to white was then confirmed for me when I was growing three plants of Cherokee Green for seed production and one plant had all white fruits, which were lousy tasting.

When I first grew GD is was very stable, but then Neil in IL and Jeff in Canada, and later I found out the same had happened for I think it was either Lee Goodwin, here at TV or Steve of Heirtage seeds who got plants with fruits that had a clear epidermis, and it was decided between Jeff and Neil and myself to call it GDF.

It was the first time that I'd grown a GWRipe with a clear epi since I trialed a variety for Tom Wagner back in the mid-90's, along with about 20 others, and the variety name is Verde Claro, and I love it.

No, I never suggested a cross that led to GDF, what I've always thought is that the epidermis gene was unstable and was flipping back and forth, and I still think that today.

Subsequently I've seen that many folks have grown GD and got both GD and GDFplants, and the reverse is also true.

Since both taste the same I don't have a problem with it at all and I don't see why anyone else would.

It's kind of a twofer situation if you will.

On my list of growouts for this season there's one GWRipe variety that's a beefsteak and I was delighted to be given those seeds since it sounds as though it has a clear epidermis and I'm also expecting another GWR from across the pond but I have no idea if that one has a yellow or clear epidermis.

I've grown lots of GWripes, I love them and just wanted to share some info about Green Giant. Those in the south who grew it usually got no amber blush at all, suggesting the epi was clear, not the normal yellow epi that most GWripes have. So Craig, seeing no amber blush in Raleigh, sent seeds of it to his friend in MI and to me, and we got the normal amber blush. I asked Reinhard Kraft about it , he was the original source, and he said that he grew his tomatoes in a greenhouse where it was quite warm.

So it would appear that there was a temperature induced phenotype change that was at work due to gene expession.

So no, I didn't suggest a cross, ever. It's really no different with variety Green Grape, which as released by Tom Wagner was indeterminate, but it kind of morphed into a determinate and Tom saw that himself when he first visited a greenhouse overseas where plants were being grown.

I also had a variety, I can't remember the name now, I'm sure Craig can, where you could save seeds from plants with PL foliage, sow them the next time and get plants , some with PL and some with RL.

Same thing happened with the variety Dr. Carolyn Pink, seeds sent to me by an SSE member. Sow seeds of Dr. Carolyn Pink and get large cherries, save seeds for it and get plants that have either large pink cherries, or small ones that are the size of the variety Dr. Carolyn and there's a couple of threads about that here at TV .

Same with the variety Kazachka seeds from Andrey in Belarus, where you can get some black cherries that are round on one plant and another plant will have what I call minibeefsteaks. When I asked Andrey about it he said he got the same results.

My point concerning the examples I've just written about?

Having flip flop of a given gene one can get different phenotypes and the genes involved have been quite varied, from fruit shape to leaf form to plant habit and also epidermis color and environmental variables such as temperature can also change the expression of genes as well.

I hope that helps.

Carolyn, who forgot one issue. Gunnar it isn't a matter of pure homozygous genes as I see it since there are even environmental variables that can alter phenotypes, such as temperature, as I mentioned above. I have no problem at all with Baker Creek saying you get both GD and GDF from seed puchased from them, but I don't think any number of generations is going to lead to an homozygous anything. Same as with the Dr. Carolyn Pink fruit size flip flopping and also the Kazachka fruit form flip flopping, to geve just two examples.
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