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Old September 13, 2019   #8
KarenO
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Join Date: Oct 2012
Location: Vancouver Island
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Quote:
Originally Posted by bower View Post
A bigger grow out is certainly worth it, especially if looking for outliers. You mention the dryness of the fruit as a trait you didn't want - it's certainly a common paste trait, and I suspect that is coming from Heidi, and if affecting all of them, it appears to be dominant. So a bigger F2 might not get you anything different, but a bigger F3 could do it.
The worst thing with a dominant trait like that, you have no way of knowing if your selected fruit is homozygous or heterozygous for it.

So ideally your minimum F2 growout would be large enough to net you two promising candidates, and by growing the F3 of both in the amount needed to get a recessive, you'd have more certainty of finding it.

Planning alas is easy in hindsight, when the surprise trait has already turned up.
Just another comment too about Beta and linkage - what I also found was that segregation didn't line up with expected numbers - you would have to grow more to find what you're looking for. So bigger growout is good from that POV too. But it might be a LOT more if the linkage hasn't been cracked in the cross. This is the reason for backcrossing or any cross between unstable generations, to increase the chance of breaking it.
(None of these issues apply to the awesome crosses you made, KarenO , with bicolor genetics, which produced such a beautiful array of diverse tomatoes with no interfering linkage issues.

My main point is an F2 growout of 8 plants is a very small representation of the possibilities in any wide cross.
KO
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