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Green when Ripe & Beta-Carotene

holtzclaw
12 years ago

I am wondering what the results would be of crossing the green when ripe trait with the increased beta-carotene trait. I suspect there would be orange fruit in the F1. I'm interested in what happens when these two traits recombine in the F2. Has this already been done? Is it something I'm familiar with and just didn't realize?

Comments (7)

  • mulio
    12 years ago

    I did not see completely orange fruits in a cross I made with Beta in the F1 so I do not suspect it will show complete dominance. So It may be rather intermediate in color siding to a reddish orange. The orange color was not fully expressed until the F2. I can tell you this; it will probably taste terrible. Beta pigment carries its own unpleasantness.

    The F2 should have range of colors, mostly that intermediate red. The ratios of colors depends on what genes were present in the homozygous Beta parent that may have been masked (most likely the Beta is masking the wild type red flesh). Should see a range of red, orange, yellow and green. Assuming it's a typical dihybrid segregation the ratio should be 9:3:3:1 accordingly (of course one needs a larger population to see that.)

    When the green flesh has mixed with other orange crosses I have done, visually it really just makes the seed gel cavity green with minimal effect to the majority of the orange flesh types. It is subtle and there but it isn't as pronounced as when it mixes with red (brown or purplish color).

    BTW, green flesh is also not completely dominant. Heterozygous fruit for gf can be spotted on close inspection but one can be misled on this depending on how ripe the fruit is when they look at it and maybe even environmental conditions. It's a subtle change in the flesh color. Going by the seed gel can throw you off because the seed gel may not ripen as soon as the flesh.

  • mulio
    12 years ago

    This is an example of the intermediate form (B/+) I got in the F2 that is like the initial F1 I saw with this cross.
    {{gwi:1379092}}

    "+" just means "wild type" or normal expression of that gene locus.

  • mulio
    12 years ago

    correction:

    "BTW, green flesh is also not completely dominant. "

    should be "completely recessive"

  • holtzclaw
    Original Author
    12 years ago

    I appreciate your prompt and thorough response. Most of all, I'm glad for your offered assumption that the taste would be terrible. My curiosity is cured. My most attractive tomato this year is one with an undesirable texture. I don't want to go there again.

    You will probably already be familiar with a book I'm enjoying. It is by Chittaranjan Kole. Since its cost is $299.00, I am reading it through GoogleBooks for free. Catch it while the review is still on line. I suggest beginning on page 61.

    Can anyone tell me what cultivars are examples of (Ip) Intensified pigment? Or even cultivars that are high pigment 1 or 2 (hp-1)(hp-2j)? I can only find that "Manapal" is a cultivar with (dg) dark green, an allele of hp-2.

  • mulio
    12 years ago


    L to R: 'Manapal' normal vs 'Manapal' dg mutant

    To clarify something here, the variety 'Manapal' itself is not dg. Rather a mutant of 'Manapal' was found expressing dg. Dark green is now known to be an allele of hp-2 or hp-2dg.

    The high pigment genes are problematic in that they have issues with germination, seedling mortality, brittle stems and early leaf drop. This is why you probably have not found anything of these released. I do have hp-1 lines. They are interesting because the fruits have intensified flavor, a different (firmer, but not dry like commercial types found in stores, and pleasant) texture, and a higher vitamin C content. I will eventually post pictures of them at other accounts (@kctomato or k.c.tomato on FB) later this winter. Another person who goes by frogsleap (@Frogsleapfarm or 'Frogsleap Farm' on FB) has some material that is hp-2 (I don't think his stuff is hp-2dg). I am not sure he has posted any hp-2 material yet this year. I have been waiting for him to post some.

    Ip I have read does not have the same problems as the hp mutants. I have not seen this material myself. Ip came from S. chmielewskii and was bred into "normal" tomatoes in the early 1970's. It could be that few have attempted to use it because it is a dominant gene and the original line would likely contribute negative genetic drag of carry over from the S. chmielewskii parent.

  • holtzclaw
    Original Author
    12 years ago

    Thanks for the info on "Manapal". I would have ordered it and been disappointed. Thanks also for the photo of dg. Now, more than ever, I would like to try to grow some of the hp/dg or Ip tomatoes. The problem is obtaining seed for a start.
    The book Vegetables by Kole is how I learned that dg and hp-2 are alleles on chromosome 1.
    I can't connect to the kctomato account because it is twitter and social networking is blocked from the computers at our library.
    I'm investigating dark leaf varieties because hp's often have darker foliage.

  • mulio
    12 years ago

    Tom Wagner might have some hp lines he is selling. The problem there is it may not be from a stable line though since it is recessive once you see hp it should always be in following generations. If it is segregating material with the potential for hp most of the seedlings that will grow wouldn't be hp and you will have a learning curve figuring out which ones are hp. There IS a way to segregate the seedlings using the yellow film technique but that would probably be a hassle for most to find the right material and setting up something to grow them in that kind of light. That info is even online I think via RTGC papers.
    To me it was evident the first time when the fruit set. Even in the green stage it is noticeable. One can sort of tell before that if you know the material it is in anyway. Foliage will likely be darker and the plants will generally be shorter.

    This is a picture from last year of hp-1 segregating in material that had other traits which might confound what you are seeing (dark green shoulders and heterozygous for green stripes). But when you see these fruit compared to others it is clear they are hp. The picture is taken about 10 days apart as the fruit ripened. Notice some faint stiping in the fruit from "gs" in the less mature stage. Also note the rather twisted PL foliage that seemed to go with it in this instance and this next generation (I did not note nor get a photo of that in the parent line which was RL). Notice the intense red color in the mature fruit. hp fruits have a wonderful color to them that really stands out.

    {{gwi:1379094}}

    {{gwi:1379096}}


    hint - sometimes you can see cached blocked pages via google but that may not work for images.

    See if they blocked twitpic from link below

    In winter I will also post pictures at The Tomato Garden

    Here is a link that might be useful: twitpic link

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