red skin
 

After looking at all the colors in tomato flesh and the genes that cause them and the stripes and bi- colors and the blue tomatoes I finely noticed skin colors and their effects. I saw some interesting color combos in frogsleap farms blog with yellow flesh and red skin. Today I was looking at two tomatoes from sister plants from a f3 between a pimpinellifolium and a black sea man. One looked like a dark black tomato from the outside but bright green inside and the other one was super dark red outside. I cut it to see if it too was green inside but it was red. As I looked closer the skin was much darker than the rest of the tomato. I pealed some off and put it on a white sheet of paper and it was red. I looked again and again and checked to see that I only got skin and I am pretty sure the skin is indeed red. I have searched everywhere and can find nothing about red skin on a tomato. The only information I found at all was on frogsleap farms blog. Does anyone know the name of the gene or have any info ?

craig

I've been referring to that trait as, "opaque-red" skin ([URL="http://the-biologist-is-in.blogspot.com/2014/04/the-color-of-tomatoes.html"]in a blog post on tomato colors[/URL]). I've also seen it in fruit derived from [I]S. pimpinellifolium[/I].

It isn't surprising that you didn't find a gene name. Lots of traits have not been examined in detail and then published about.

I've taken to assigning numerical names to genes that have become apparent in my breeding work. (I haven't done any crosses to examine the opaque-red skin trait yet, so I don't have a number assigned to it.) The lines I have show the trait much less than some from Frogsleep Farms, so I expect theirs would be a better starting point to examine its genetics.

I came across another discussion of this sort of trait.

[URL="http://www.tomatoville.com/showthread.php?t=31770"]http://www.tomatoville.com/showthread.php?t=31770[/URL]

Thank you for the information. Since not much is known about this opaque red skin, I think I will use it to make a lot of crosses. I am already trying to find the best tasting yellow tomato to cross it with.

My hypothetical plan to examine the genetics of this trait falls into three main steps.

[QUOTE]1. Grow selfed seeds, to examine if it is homozygous or heterozygous in your first example. If not all of the progeny all have the trait, it would appear heterozygous and dominant.

2. Cross with a few different color types (white, yellow, orange, green) and grow a few F1s for each. Grow larger numbers (20-30) of F2s from each cross. Comparing the F1s to the respective F2 family, as well as the combinations in each F2 family will let you see how the trait is interacting with the established color genes.
[/QUOTE]This trait and the typical bi-color trait appear to be irregular expression patterns of the genes in the carotenoid biosynthesis pathway. It may turn out they are caused by the same gene, with other formerly-hidden genes driving the differences in patterns. This leads to my third step.

[QUOTE]3. Cross with a typical bi-color type, such as "Ananas Noir". If the same gene is involved, the F1 and all F2s should have various bi-color patterns. If different genes are involved, the F1 and a portion of the F2s will not be bi-color.[/QUOTE]I would be really interested in how things develop for you. You already have good starting lines for this project, while all I have right now is a vivid imagination.

I grew out three different garden plots this year with about 120 tomatoes total. I had 30 plants of the (f2)between my Pimpinellifolium x Old Sea Man. That was my only garden that didn't do well. It had deer, high winds and you name it. I was looking for just the darkest black tomato out of the group. I got a very poor sampling and was lucky to pick out anything at all. Funny thing is I took a cutting from the red skinned plant. I had been watching it for some time because the immature fruit seemed to be much darker green then everything else. I was hoping for a dark black tomato so I took a cutting in the fall because deer were killing my plants. If I can get my cutting to flourish during the winter I should have plenty seed to share with you. Do you think the bi - color from the Old Sea Man has something to do with it? Do you think there is any modifier genes involved?

[QUOTE=Minnesota Mato;437143]I grew out three different garden plots this year with about 120 tomatoes total. I had 30 plants of the (f2)between my Pimpinellifolium x Old Sea Man. That was my only garden that didn't do well. It had deer, high winds and you name it. I was looking for just the darkest black tomato out of the group. I got a very poor sampling and was lucky to pick out anything at all.[/QUOTE]

My new place has deer wandering through all the time. (The recent snow has emphasized this for me very well.) We've been talking about installing electric deer-fences so we can have a chance of getting anything at all!

[QUOTE=Minnesota Mato;437143]If I can get my cutting to flourish during the winter I should have plenty seed to share with you.[/QUOTE]

That would be very nice of you. I keep being surprised by the collaborations I've seen (or been involved with) that arise here on the Tomatoville forums. ;-)

[QUOTE=Minnesota Mato;437143]Do you think the bi - color from the Old Sea Man has something to do with it? Do you think there is any modifier genes involved?[/QUOTE]

I really like the theory that the bi-color trait of OSM is being expressed differently due to a modifier, as it appeals to my peculiar sense of algorithmic simplicity. This is such a new trait to be examined, however, so it could be an entirely disconnected trait. We have to do the cross to find out.

Here are some pictures. I pasted the skins on a white paper and held it up to the light. You can really see the difference between the yellow and the red. The side view is hard to see but the skin is quite a bit darker.

Very cool. I've noticed red pigmentation of the sub-epidermis - but not the epidermis per se. Perhaps I'm jumping to conclusions and haven't look closely enough. In my crosses this red coloration of the skin (epidermis and/or sub-epidermis) appears to be due to a recessive allele of a single gene.

I've seen this in one of the pimpinellifoliums I grow. It is linked with excess chlorophyll in the epidermal layers just beneath the pericarp. You should be able to visually pick out these plants because the leaves have a funny green color and the fruits are intense dark green. I also noted that these fruits were much sweeter than normal in my garden. They were a long ways from Sungold sweet, but still quite a bit sweeter than most tomatoes.

I did not notice a funny green color in the leaves but I did notice an intense dark green in the fruits. How many Genes do you think are involved or is it a single recessive gene? Does this have any connection to higher lycopene levels you have seen in in some pimpinellifoliums ?

This is just an educated guess, but I suspect there will be at least 2 genes involved because it does not behave as a straight recessive. Increased chlorophyll results in increased lycopene.

I hadn't noticed increased chlorophyll in the variety where I noted the trait, "Tiny Tim", also derived from [I]S. pimpinellifolium[/I]. It could either be not obvious, or we could have two separable traits which show increased lycopene in and just below the skin.
[IMG]https://farm8.staticflickr.com/7512/15869009561_c68a92a712_n.jpg[/IMG]

Fusion, I have read your posts on high lycopene chlorophll correlation in pimpinellifolium and wonder if this could be something similar with an added or missing modifier gene. If not do you think this red skin x LA2093 would produce even higher levels of lycopene ?

I would say that it is an open question. Probably the best way forward would be to grow and stabilize what you have and compare it to the current high lycopene varieties on the market. That should tell you if it is something new. A tomato that accumulates heavy lycopene just beneath the epidermis would be interesting to commercial breeders.