I recently completed my first seed adventure with some PUCK Bc3. It went a little rough since the plants were burned badly midway through flower. I successfully harvested plenty of seeds though and am now growing a handful to test out. With that being said, I’m a bit confused as to the variation from their parents. I used 5 males and 5 females, and there was good uniformity througout them. If I understand correctly, they were the F1 generation, so shouldn’t the F2s have this uniformity too? I’ve had a lot of mutated seedlings and scraggly unhealthy ones, nothing like when I popped their parents. 4/14 seeds didn’t survive from the original pack but if I recall correctly, only about 4/16 of the F2s came out normal. (A few didn’t break soil).I would’ve been severely disappointed if that had been the case with the $100 pack, so what gives? Is this because of mistakes on my behalf (like the burn)? Am I able to stabalize them more by selecting some keepers and open pollinating those to F3? I considered buying another pack and trying again, but am unsure if that’s necessary.
Backcrossing can only stabilize a line to a limited extent. By breeding back to the original parent, you keep reinforcing the genetic structure of the original parent - but it’s pointless to backcross a homozygous line, since they’re already fully stable. Good backcrosses are instead heterozygous mixes of genes with the dominant genes of the original parent reinforced. When you breed them, that dominance will most likely be broken because there’s a 50/50 chance on each side of the recessive gene being passed instead. In other words, not stable. Continuing to make good selections down the line and breeding to higher F-gens should stabilize the line into something more homozygous, i.e. more of an IBL. Buying more packs probably won’t help you breed it into stability, though it will give you more of those uniform heterozygous seeds if you want to just pop them and clone. Might be simpler.
Ok so a few things slightly confusing here for me. In this case it sounds like you bred PUCK Bc3 x PUCK Bc3… If this is the case it wouldn’t ‘technically’ be an F1… it would be PUCK Bc4.
PUCK Bc4 would be highly inbred, enough to call it an IBL. If genetics are stable, you may seen some uniformity. If genetics are unstable you will see a lot more of the detrimental affects from inbreeding.
If you take any PUCK Bc4 female and breed it with any male NOT from the PUCK lineage you should have improved vigor in those seeds. They will also be true F1s.
This is a typical expression for how to take a strain to F2:
P1 + P2 = F1
F1 + F1 = F2
F2 + F2 = F3
…etc
The F1 male and female MUST be from the same batch of seeds otherwise it would technically be a P1 in a new F1 cross. Also P1 and P2 must be genetically different from each other, otherwise it’s backcrossing and complicated.
As I understand it, typically a backcross refers to breeding with the original parent and what OP is doing would be referred to as a BX3 F2. It’s standard inbreeding and should bring the line closer to being homozygous. Backcrossing again should not bring it any closer to being homozygous though, which is pretty much the definition of an IBL as I understand it. Backcrossing again should bring it closer to the original cultivar, which is not an IBL.
Ah yeah good catch. This is why I think backcrossing and selfing can get kind of annoying when it comes to how we denote lineage. What you said makes sense.
I guess it kind of depends on how we label IBL too because some people will say taking an F1 to F2 technically makes it an IBL. Maybe we should refer to homozygosity rather than IBL, which I think is the goal of most inbreeding programs.
F2 is where you will get the greatest amount of genetic segregation. It’s where you will find the greatest amount of variation and also where you can find the best selection. But in general F2 is a bit of a shit show.
