[Miraculous Meds]

If I want to inbreed a F1 strain, would there be value in keeping males from the f1, or f2 generations, if my goal were to breed to the f4 or so, to stabilize a trait?

[MJPassion]

Imo, you'd be better off searching for keeper males in the F2 or F3 gen. There's typically not many homozygous traits in F1 seed stock.

Only real value of the F1 is for making F2s.
Strictly my opinion.

Originally Posted by Miraculous Meds

If I want to inbreed a F1 strain, would there be value in keeping males from the f1, or f2 generations, if my goal were to breed to the f4 or so, to stabilize a trait?

Self several best F1 females at least two generations, your S2 will be far more true breeding than your F4. Keeping a few F2 seeds lines in the fridge will be a good idea too if you can.

[Miraculous Meds]

Thanks for the responses guys.

I think that there might not be value in keeping a male till f3 or f4. Maybe back crossing is better done to the female.

What is more common, to back cross to a male, or female?

[GMT]

Couple of points. If inbreeding, you use siblings or cousins, not parents, as as you correctly said, that's back crossing. You stated the goal to be stabilisation, inbreeding is the way to go. You won't stabilise by bacrossing to an F1 parent, no matter if you use male or female.

[MJPassion]

Seems the best seedlines use males that have proven their worth for back crossing. Afterall, they are the more difficult of the two to evaluate.

The F2 gen should give rise to an extremely variable population allowing you to see more expressions than generations that follow.

At F2 and later gens, you are attempting to grab the traits you want & recombine them into your final goal.

F2 is where the recessives show up. It is the first gen to use for Selfing, imo.

[Miraculous Meds]

I think this all makes a bit more sense now. So the f1 males can be culled after u make a population of f2's.

Do breeders/seed makers that take a seed line to f5 save f2, f3, and f4 males to work with then? Or maybe they would just dip into the f3 seed pool if they wanted to work with a male from that generation again?

[Ptone]

Originally Posted by MJPassion

Seems the best seedlines use males that have proven their worth for back crossing. Afterall, they are the more difficult of the two to evaluate.

The F2 gen should give rise to an extremely variable population allowing you to see more expressions than generations that follow.

At F2 and later gens, you are attempting to grab the traits you want & recombine them into your final goal.

F2 is where the recessives show up. It is the first gen to use for Selfing, imo.

So you're saying that S1's made from F2's are more stable and homozygous?

If you are at F2 and had not mated the right F1 male(s) with your selected F1 female(s), your F2 will not be as good as your selected F1 mothers and so the next generations won't be as good too because of the wrong F1 male(s) used. I like this quote "The progeny must equal or surpass it's parent in overall quality and desirability to be considered for future breeding". Good luck to find the right male(s) without BIG progeny testing. Winners males are winners because of their progeny not their phenotype. To bred true traits you will have more success in Selfing directly your selected F1 females.

The difficulty to find the right F1 male(s) and the heterogeneity of the F2 will make you a even more difficult task to find the right female with the right genotype in the F2 and so Selfed F2 could be homozygous or not depending of the individual chosen to Self and only if your F2 line is good enough first ie the right F1 male used.
Remember basically F2 gives 1 AA, 1 aa and 2 Aa.

Ask you the question, do you want to see the good traits of your selected females F1 diluted or gone in the F2 ? because if you don't find the right male(s) F1 it could happens. Its easier to select the female part but the male side ? Be prepared to progeny test dozens of males...

Selfing selected females F1, S1, S2... is the quickest road to bred true the traits you see in your F1 females. When you will have the right Selfed generation of your best females you will have a true breeding line for the traits you want and you will be able to restore the dioecy in reintroducing the Y chromosome if you want via a backcross to an ancestor regular(female:male) line like your F2 or an outcross to an unrelated regular line.

[MJPassion]

Originally Posted by Ptone

So you're saying that S1's made from F2's are more stable and homozygous?

No.
I'm saying that due to the variability of the F2 generation a person is more likely to find plants already exhibiting homozygous traits.

When you find plants that exhibit the traits being searched for then by selfing and growing those seeds you can tell if the plant is homozygous for that particular trait or combination of traits.