Thread: Backcrossing
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Old May 6, 2015   #16
crmauch
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Join Date: May 2013
Location: Honey Brook, PA Zone 6b
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Yes, that's pretty much the 'chart' I was looking for. In this case on this page: http://kdcomm.net/~tomato/gene/genes3.html it has a way to enter the number of recessive genes and it gives you the number of plants.

However - can you not speed the selection for dominant genes by following a line of a plant? For each plant that has the set of genes you want, plant out a large number of plants (keeping each set of seeds segregated by parent). If over a very few generations that "line" is not having the recessive gene being expressed, won't you have bred out the recessive in a speedier fashion? This of course assumes other factors like taste, productivity, etc aren't being affected. If none of our lines are 'pure breeding' for the dominant gene, you have to start selecting the best out of your still segregating lines.

Quote:
Originally Posted by carolyn137 View Post
I think that same information is also given at Keith Mueller's website in a very different way where he explains and gives numbers as to how many gens need to be grown out to give different percentages of purity.

http://www.kdcomm.net/~tomato/

Go to Culture, there go to tomato gene basics, read that and then click on the segregation link at bottom of that.

Carolyn
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