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Thread: Questions on hybrid vigour

  1. #1 Questions on hybrid vigour 
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    Recently talking with some friends about genetic variation. I spent plenty of time to really understand the concept of hybrid vigour. But here are some of my doubts. Not sure if you find my questions reasonable but I would just like to ask. Feel free to call me an idiot if you find the topics useless
    1: For a self-polinated flower, is there any chance for it to adapt to environment better than a cross-polinated flower? Is this different for different species?
    2: Is there any "grey area" in the theory of hybrid vigour?
    3: Is there any counter example of it?
    Thanks


    "Great target begins with smaller ones"
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  3. #2  
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    The concept behind hybrid vigour is that deleterious alleles can be rescued by more fit homologues. Thus, in general, outbred animals (etc) will be more fit than inbred animals (etc.) The concept is generally sound.

    However, at the genetic level, (rather than the organismal level) homology at a specific locus can be advantageous. This would be particularly true for any trait in which the gene products behave in an additive manner. I can provide an example if it would help illustrate the concept.

    A self pollinated flower could perform better than a cross pollinated flower in some cases (some species prohibit cross pollination, as you are probably aware.)

    At the organismal level, cheetahs are an excellent example of a very highly inbred species that appears to do quite well, confounding the basic notion of hybrid vigour.


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  4. #3  
    Forum Freshman Nikolas_Miller's Avatar
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    Im not quite sure about your response Free Radical, although i understand your use of animals was metaphorical there is a large enough difference between the advantageous genetic variability in plants and animals that the effects in inbred plants compared to inbred animals is almost an illogical comparison.

    Self-Pollinating plants, which are "perfect" (having male and female parts), certainly are not only subject to their own gametes. Cross pollination still may exist in perfect flowers. When this cross pollination does occur there may be a resulting the most advantageous genetic result. From here, the progeny may then self-pollinate by chance for many many generations and survive with out tainting their genetic perfection. This would be an example of how self-pollination may have a better chance at adaption.

    As far as grey areas go in hybridization (heterosis)... Its all preety fundamental and basic, the only problems people have hybridization is in the economics of the process. In the 1960's most hybrid corn was produced via male sterility (emasculation) untill those plants became susceptible to a race of Southern Corn Leaf Blight disease. So now female corn plants are detasseled which costs labour.
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  5. #4  
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    I bow to your superior knowledge on plant genetics.

    Cheers!

    FR
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