Quote:
Originally Posted by bower
So after reviewing my results this year, I have seen a lot of segregation in F2 and again in F3, and would like some advice about the generations 4-7, what kind of segregation to expect and how many plants should be grown to capture the traits desired, which I selected in F3.
My impression is that this may be different depending on the cross. In some the overall traits appeared fairly stable even in F3. I have also recessive/desired traits selected in F3, but while leaf type and fruit color are expected to remain, there are many traits which are additive and still expected to vary. Some crosses appeared to have fairly stable, desired traits in F3 and easily selected for the best from 4-6 plants.
I also know linkage can play havoc, and I'm seeing that I think with growth habit segregations in F4. But I would like to know how many plants you would grow in gens 4 - 7, for segregation in:
fruit quality = taste and texture
fruit size
earliness
productivity
other traits that pertain to plant health? I have not done any selection on the basis of health except this year putting some plants outdoors there were perhaps differences.
What are your thoughts on stability, perceived or actual?
Every advice or comment about your experience would be much appreciated!  |
First, what varieties are you crossing, viz wide or narrow crosses for it makes a difference as to how long it will take to stabilize something in terms of genetic segregation.?
And I think if you go to Keith Mueller's superb website you'll find most of the information you need as to most of your questions, especially about segregation.
http://www.kdcomm.net/~tomato/
I've never bred for OP's but have dehybridized some F1 hybrids so needed the same kind of information and Keith addressed that very well.
Almost forgot,but when you said breed for OP's, does that mean you are introducing various wanted genes,one at a time? I ask b/c that makes it much more difficult since you have to assess that incorporation at each step, and that's difficult since it means challenge experiments at every step. Which are done by registered labs who do that and that's big money.
Carolyn