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nugrdnnut

F1 stability/reliability question

nugrdnnut
9 years ago

I was thinking about the discussions about F1, F2, ... but I haven't read about "stable" or "reliable" F1 hybrids.

How does the seed supplier know that the F1 seed (say Sun Gold) will produce the Sun Gold tomato and not a tomato exhibiting more of one of the parents features rather than the expected F1 tomato?

I hope this thought and question makes sense.

Replies are appreciated.

Regards,
Tom

Comments (19)

  • chewy2u
    9 years ago

    this is not a real problem. if the new plant comes from the Sun Gold genetics then it IS a sun gold tomato. small variations always exist. But the idea is to eat the tomato. in that respect all the tomatoes meet the standards of the sun gold by definition.

    your question is more meaningful to a person who grows the plants for future breeding purposes. But for eating the tomatoes there is no practical problem.

  • seysonn
    9 years ago

    OK. Here is my take.

    Say they (breeders) take two varieties and cross them (one donor, another recipient) . Then when the fruits ripen, they save the seed . And plant a good sample of them. Then they evaluate the outcome. If it was as expected or was unexpectedly(accidentally) desireable, they woudl continue that process in an even larger scale, save seeds and market. SO THAT IS F1.

    You and I buy the F1 seeds and plant them. The breeders have already figured it out what we are going to get.

    The puzzle part is if we save F2 seeds from our tomato and grow it the next season, what will we get ? I don't know the percentages and numbers. But we might get:

    ---1- similar to the F1 that we bough and planted
    ---2- We might get some thing that looks like the mother (unknown to us)
    --3-- We might get something that looks like the father (unknown to us)
    --4--- It is possible that we might end up with a 4th and 5th mystery kinds that may look, say more like the mother and less like the father or vice verse.
    The F2 outcome would be some kind of Statistical Probability Distribution. That means there won't be a set predetermined outcome.
    It is logical to think about how the two are crossed, i.e, which was the mother and which the father.

    So it is possible (low probability) that your F2 fruits might turn our to be even better than the F1 fruits.

    EDITED TO ADD FOLLOWING:

    Not all the hybrid seeds are "F1". I have a packet of Burpee seeds in front of me it says: BUSH STEAK HYBRID.
    Nowhere on the package you can find any "F" number. It might be an F2, F3, ... They won't tell us. In fact it might just be an stabilized OP, that they are selling as "Hybrid". We don't know, unless we save seeds and plant and find out.

    This post was edited by seysonn on Tue, Oct 14, 14 at 6:15

  • carolyn137
    9 years ago

    Tom, it's the person who bred the tomato variety, not the seed supplier, which I interpret as being the vendor, whose concern it is in ensuring that a variety is an F1 hybrid and if a pack says hybrid, that's the same as saying it is an F1.

    With commercial varieties, here's how it's done, I know I've explained this here at GW many times, but don't have the time to go searching.

    There are two breeding lines, lets call them line A and line B. Stating with line A they breed in traits for high solids, uniform ripening, various disease tolerances, etc, one at a time so that the last OP in that line has what they want.

    The same is done with line B. There can be up to 4 parental inputs in each line, so 8 all together.

    Then the last OP in line A is crossed with the last in line B and the result is an F1 hybrid.

    How stable? Very stable. In the past the female last OP was done by emasculating blossoms manually, which is very labor intensive, so sometimes not all of the ovules in the tomato ovary are fertilized by the applied pollen from the male. And that can lead occasionally to what are called mule plants, which are much larger than true F1 plants and have no blossoms or fruits.

    In the past I had several commercial farmer friends and it was easy to see those huge plants with no blossoms, no fruits at all.

    However, in the past maybe 10 years breeders have been using what are called male steriles which gets around the manual part, and that's worked out very well. Each blossom has female and male parts, the latter being the stamens with pollen. With male steriles that pollen is no good so such blossoms cannot self pollenize.

    Earlier hybrids such as Ramapo and Big Boy and Better Boy, etc, did have only two parents and I've grown all above and never have seen a mule plant, ever. But then those with two parents don't have the package of genes that many look for today in terms of disease tolerances, etc.

    I hope that helps,

    Carolyn

    This post was edited by carolyn137 on Tue, Oct 14, 14 at 22:40

  • nugrdnnut
    Original Author
    9 years ago

    Thank you all for your replies and the time and thought it took to do it.

    What got me thinking about this is that this second year of growing Sungold tomatoes (using the same seed supplier) and this year I had (~10%) of the tomatoes have a more reddish look and taste more like a red cherry tomato.

    Again thanks for the replies.

    Carolyn, btw I did search, but didn't really get the answer that you provided here!

    Regards,
    Tom

  • Aaron_Wisconsin_
    9 years ago

    Hi Tom,

    really good question. Commercial Hybrid F1 always come from two stable parents (inbred), therefore you always have predictable and stable F1. And as a result, inbreds are REALLY valuable to breeders and key to commercial companies.

  • carolyn137
    9 years ago

    Aaron, methinks you might be the Aaron I once knew so well when you were still in Iowa ,

    Long time no talk to, but just briefly, 2014 is the last year I'm going to be an SSE listed member, they are going in a direction I'm not comfortable with.But since I've been a long time Lifetime member since 1989 I'll still get the publications and be able to follow what's happening,

    I still make a huge annual seed offer elsewhere and have several wonderful persons who do the seed production for me, most varieties new to all or most since I fell in 2004 and got permanently placed in this walker and it was then that I decided to do that. My job is to find those varieties and I've been very successful in doing so with many contacts in many countries as well as the US.

    So a big grin and Hi to you and if you aren't the Aaron I know, a big grin and Hi as well.

    If you have the time I'd like to catch up on you and the family, etc., and best to e-mail me at cmale@aol.com

    Carolyn, now 75 but still perking along with med problems here and there but her mouth and the tomato section of her brain and her fingers still work OK most of the time. LOL

  • Aaron_Wisconsin_
    9 years ago

    Hi Carolyn, I am not the Aaron you are looking for. Nice to hear your stories, though. :-)

  • seysonn
    9 years ago

    To my understanding, stability in things like hybridizing can be best explained by statistical probability on some kind of distributions curve. So then you cannot hope for 100% stability. Maybe an 80% would be a good number within 2 standard deviation.
    JMO.

    Seysonn

  • fusion_power
    9 years ago

    Look up "doubled haploid" and you will get an idea what is involved. The F1 is extremely consistent because it is a result of crossing two highly stable inbred lines which produces the F1 hybrid. Given that the inbred lines are highly stable to start with, the F1 offspring will be so consistent that for all practical purposes they are clones.

    This is a good way of looking at hybrids involving 2 highly inbred parents, but what about a 4 way hybrid?

    (A X B) X (C X D)

    When line A is crossed with line B and line C is crossed with line D, the purpose is to produce two F1's each from a highly inbred pair of parents. Then the resulting seed are crossed to produce the 4 way hybrid where each offspring has some inheritance from each of the four parents. The parents are carefully chosen to produce consistent progeny, to exhibit significant heterosis, and to show excellent combining ability. The resulting F1 seed are then sold for production. They are NOT identical in the F1, however, because of the selection pressure on the 4 parents, they appear so nearly identical that they cannot usually be told apart.

    Why would you want to produce a 4 way hybrid? I have to lean on Maize to explain. When maize is inbred, the usual result is a ratty ear of corn with very few kernels. It is not productive enough to make an F1 hybrid which can be sold to produce commercial crops. But the offspring of that first cross will be very productive. So when seed of the A X B cross is planted, the result is a nice solid ear of corn with little resemblance to either of the ratty looking parents. To solve the problem of producing enough seed, two F1's are crossed - (A X B) X (C X D) - which produces seed in enough quantity to then produce commercial crops of corn.

  • carolyn137
    9 years ago

    To my understanding, stability in things like hybridizing can be best explained by statistical probability on some kind of distributions curve. So then you cannot hope for 100% stability. Maybe an 80% would be a good number within 2 standard deviation.
    JMO.

    &&&&&&

    Please look at the link below, it's Keith Mueller's excellent website, click on culture and the links having to do with hybridizing and segregation.

    As Keith shows, homozygosity is essentially 99% at the F8. AT the F14 it's about 99.9%

    The above for a two parental OP cross, not the more complicated ones that Fusion posted about.

    I had to go out to the F7 when getting what is known as OTV Brandywine stable, but only the F3 when I did Ramapo F1. It depends on the specific genes that a variety has as to how they segregate and how closely the genes might be linked ,from the F1, whether a deliberate cross or an F1 from an accidental cross one from X pollination,

    And I did go into the two breeding line explanation for how most commercial hybrids are bred in my post above.

    Carolyn

    Here is a link that might be useful: Stability/Segregation

  • seysonn
    9 years ago

    All I am saying is that "stability" is a statistical probability. You can assign a high probability to a given cross/hybrid but still it is a probability. 80% ? 99.9% ? they are probabilities. This is science. For a backyardner like me it is not that important, anyway.

  • carolyn137
    9 years ago

    If F1 stability is not important to you as a backyard gardener it begs the question as to why you posted in this thread,

    You posted:

    (So then you cannot hope for 100% stability. Maybe an 80% would be a good number within 2 standard deviation.
    JMO.)

    YEs, it's just your opinion but your opinion was wrong, which is why I posted that link for you to help show that even at the F7 the probabiity is about 99% for genetic stability/homozygosity,

    Carolyn

  • seysonn
    9 years ago

    if F1 stability is not important to you as a backyard gardener it begs the question as to why you posted in this thread,
    %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

    That is a logical fallacy. That is to say "because it is not important to me , I should not be talking about it".

    Let me give you an example of this class of fallacies :

    A: smoking cigarette can be harmful to one's health.
    B: You are a smoker yourself, therefore your argument is not valid.

    Analysis: "B"'s argument is a logical fallacy. What "A" has said is independent of his smoking habit . In other words, "A"'s smoking habit does not invalidate his argument.

  • carolyn137
    9 years ago

    Again, I repeat, that I posted b/c your information about the 80% was wrong and I assumed I was being helpful to you.

    If you were a backyard gardener who did your own crosses that might be different.

    Look, you can post whatever and wherever you want to as you do already do, but I will say that you are kind of getting on my last nerve, LOL, and I think that's true for many here as well, as you should have seen with your PL/RL disease susceptibiity thread which sat there for quite a while before anyone posted. And also bringing to the front long dead threads to give yourself a place to post again, when all of that could be done in a single thread.

    Not just myown opinion.

    Carolyn

  • seysonn
    9 years ago

    >>>Again, I repeat, that I posted b/c your information about the 80% was wrong and I assumed I was being helpful to you.

    That is not the case . I was talking about statistical probability. 80% , 99.9% were just examples. But then YOU SAID:

    .>>if F1 stability is not important to you as a backyard gardener it begs the question as to why you posted in this thread,
    AND
    .>>>Look, you can post whatever and wherever you want to as you do already do, but I will say that you are kind of getting on my last nerve, LOL,

    That is not my fault. I just express my opinions. Why does it bother you so much?

    .>>>If you were a backyard gardener who did your own crosses that might be different.

    Yet another logical fallacy:
    I can talk and express my opinion about it even if I have not done it myself.

  • carolyn137
    9 years ago

    I just express my opinions. Why does it bother you so much?

    It bothers me when your opinions are not factual but wrong.

    I have no other comments to make on anything you posted in this thread to date, and perhaps other threads as well. It all depends on what you post.

    Carolyn

  • digdirt2
    9 years ago

    It "bothers" many of us so much because "talking and expressing your opinion" and in the process passing on so much wrong information helps no one and does a disservice to readers.

    Yet you never show any interest in changing your "opinion" or in learning about why your "opinion" may be wrong. This no matter how much information is provided to you. All you do is spout your opinion and then argue with anyone who differs with your opinion.

    The forum isn't your personal soap box. It is a format for disseminating information not personal opinions. Participation carries with it a responsibility to at least attempt to provide accurate information.

    Dave

  • nugrdnnut
    Original Author
    9 years ago

    Thank you all...
    most of the information shared has answered my question!

  • seysonn
    9 years ago

    It bothers me when your opinions are not factual but wrong.

    Opinion is "opinion" . does not have to be "factual". And I don't claim mine are factual.

    yet you never show any interest in changing your "opinion" or in learning about why your "opinion" may be wrong. This no matter how much information is provided to you. All you do is spout your opinion and then argue with anyone who differs with your opinion.

    That is arrogance on your part to speak so authoritatively to claim that YOU have the right answers and information. and therefore I (or others) have to change my/their opinion. If you go your way, there will be no body to ARGUE with. You do participate voluteerly in argument to prove that you are right. I just express my opinion, which obviously I believe there is validity to them until proven wrong. So then it is more on your part to prove me wrong rather than just what you think.

    And try FINALLY to learn the meaning of "FORUM".

    Opinions expressed in the forum belongs to those who express them.
    ----------------------
    BTW: I have learned few thing from both of you on this forum and I respect your knowledge and expertise in certain areas. But I disagree with you on occasions. There is nothing personal about it.
    Age wise I am about your age and education wise I have a few college degrees of my own and experience.