Oldbie gets tangled up

[Oldbie]

Ok, here goes. Firstly here’s the jist of a breeding program to bring out a recessive trait according to Jorge Cervantes.

RP = recurrent parent (a good mother!)
Dnr = donor (a good father)
F = filial (the kid)
Bc = back-cross (incest???)

Rp x Dnr =F1
F1 x F1 =F2
Rp x F2 = Bc1
Bc1 x Bc1 =Bc1F2
Rp x Bc1F2 = Bc2
Bc2 x Bc2 = Bc2F2
Rp x Bc2F2 = Bc3
Bc3 x Bc3 = Bc3F2
Bc3F2 has approx. 93.7% of the recurrent parent’s genes.

First question, given that this program is designed to bring out a recessive trait,
Is it adequate to backcross the male off-spring of the mother and father with the recurrent parent (the original mother) without first sib-mating the F1 generation?
This maybe a straight forward enough question to ask the more clued-in breeders amongst us but being a bit of a pollen-chucker (I love to cross strains and am usually happy with the results and have no intention of becoming a seed-producer for commercial gain so don’t worry, none of my unstable crosses will be released into the general public) I will simplify it further.
In order to end up with my own supply of regular seeds that are genetically as near to an original mother as possible, is it ok to skip the filial sib-mating and just back-cross the F1s with the recurrent mother for 3 generations???
Any feedback will be gratefully received.
later.....
I should probably clarify what I am trying to achieve

Rp x dnr =f1
Rp x F1 = bc1
Rp x bc1 = bc2
Rp x bc2 = bc3

Bc3 should therefore have approx. 97% 0f Rp genes if I am not too mistaken,
without all the inter-generational sib-mating???

If anybody has any light to shed on this, sally forth and lay it on me dude.
many thanks.

 

[Exotic Flower]

Hey @Oldbie,

I am definitely NO expert on such things, but, some thoughts...

Because what you're trying to get at is a recessive gene, if you just go

Rp x dnr =f1
Rp x F1 = bc1
Rp x bc1 = bc2
Rp x bc2 = bc3​

instead of

Rp x Dnr =F1
F1 x F1 =F2
Rp x F2 = Bc1
Bc1 x Bc1 =Bc1F2
Rp x Bc1F2 = Bc2
Bc2 x Bc2 = Bc2F2
Rp x Bc2F2 = Bc3
Bc3 x Bc3 = Bc3F2​

The trick, it seems to me, is that in the long way, the F1 x F1 = F2 isn't just any old F2 result that then goes into Rp x F2 = Bc1.
You have to pick out the F2 that is the 1 in 4 that has both of the recessive genes showing in the phenotype.
You can only see that in the F2, right? While the F1 must have one recessive gene from the mother Rp, it's just one.
And any old F2 is going to be 25% TT 50% Tt / tT, which aren't going to show the recessive gene in the phenotype.

And then I guess that the same logic would work for the next time you do the Bc1 x Bc1 = Bc1F2, then that into Rp x Bc1F2 = Bc2.
Instead of just skipping to Rp x Bc1 = Bc2.

In other words, by letting the inter-generational sibling crosses take place, F2, Bc1F2, Bc2F2, Bc3F2, etc.,
because it's a recessive gene you can only see it as a phenotype on these F2 level crosses.

Am I making sense? Like I said, I'm a total amateur at this kind of stuff.
Most of that comes from spending too much time reading Clarke's Marijuana Botany many, many years ago.
Though I never had the time or space to do the real breeding that I wanted to at that time.

Maria

 

[Oldbie]

Hey @Oldbie,

I am definitely NO expert on such things, but, some thoughts...

Because what you're trying to get at is a recessive gene, if you just go

Rp x dnr =f1
Rp x F1 = bc1
Rp x bc1 = bc2
Rp x bc2 = bc3​

instead of

Rp x Dnr =F1
F1 x F1 =F2
Rp x F2 = Bc1
Bc1 x Bc1 =Bc1F2
Rp x Bc1F2 = Bc2
Bc2 x Bc2 = Bc2F2
Rp x Bc2F2 = Bc3
Bc3 x Bc3 = Bc3F2​

The trick, it seems to me, is that in the long way, the F1 x F1 = F2 isn't just any old F2 result that then goes into Rp x F2 = Bc1.
You have to pick out the F2 that is the 1 in 4 that has both of the recessive genes showing in the phenotype.
You can only see that in the F2, right? While the F1 must have one recessive gene from the mother Rp, it's just one.
And any old F2 is going to be 25% TT 50% Tt / tT, which aren't going to show the recessive gene in the phenotype.

And then I guess that the same logic would work for the next time you do the Bc1 x Bc1 = Bc1F2, then that into Rp x Bc1F2 = Bc2.
Instead of just skipping to Rp x Bc1 = Bc2.

In other words, by letting the inter-generational sibling crosses take place, F2, Bc1F2, Bc2F2, Bc3F2, etc.,
because it's a recessive gene you can only see it as a phenotype on these F2 level crosses.

Am I making sense? Like I said, I'm a total amateur at this kind of stuff.
Most of that comes from spending too much time reading Clarke's Marijuana Botany many, many years ago.
Though I never had the time or space to do the real breeding that I wanted to at that time.

Maria

hey @Maria , well fancy meeting you here! this is a surprise!
are you making sense? you ask. well ...most probably. the real question is...am I making sense of your making sense.
thing is, I am chugging along on Mazar oil right now and the few botanical cogs I have in my head are not co-operating, so I will re-read when I am more together. nice to finally get some response and even nicer from a recently made acquaintance. I have to say Maria, you have impressed me- my kinda gal! you have the makings of a botanist at least; theres nothing like keen enthusiasm to facilitate learning. a total amateur, you are definitely not; you have a talent for it in my opinion. thanks Maria.

 

[Exotic Flower]

hey @Maria , well fancy meeting you here! this is a surprise!
are you making sense? you ask. well ...most probably. the real question is...am I making sense of your making sense.
thing is, I am chugging along on Mazar oil right now and the few botanical cogs I have in my head are not co-operating, so I will re-read when I am more together. nice to finally get some response and even nicer from a recently made acquaintance. I have to say Maria, you have impressed me- my kinda gal! you have the makings of a botanist at least; theres nothing like keen enthusiasm to facilitate learning. a total amateur, you are definitely not; you have a talent for it in my opinion. thanks Maria.

Thanks, @Oldbie!
Answering posts in threads is one thing, at least it's not one of those situations when you are blazing away and suddenly decide to go into the garden and actually implement all the crazy ideas that are buzzing around in your head. Until the next morning ... what the hell was I thinking? Haha!
Awaiting your response at some more appropriate moment in the near future...
Thanks for the "rep"!
Maria

 

[Oldbie]

Thanks, @Oldbie!
Answering posts in threads is one thing, at least it's not one of those situations when you are blazing away and suddenly decide to go into the garden and actually implement all the crazy ideas that are buzzing around in your head. Until the next morning ... what the hell was I thinking? Haha!
Awaiting your response at some more appropriate moment in the near future...
Thanks for the "rep"!
Maria

Hi @Maria Sanchez , having re read your response with a somewhat clearer head (somewhat is as good as it gets these days),
I realised that I unintentionally threw a bit of a curve ball, in so far as I cited a program to bring out recessive genes. I cited this example because it was the only example I could find to use as a more universally accepted way of signifying a breeding program. Other than my usual method of sampling and using the best to breed with, I simply don't have the time or opportunity to start a breeding program where I would progress to the stage of trying to bring out recessive traits.only today revisiting Jorges Bible, and getting a bit bogged down in hetro and homozygous genes, I knew I was never likely to go that far into a breeding program. what I am concerned about and trying to avoid is unhealthy gene pool diminishment. Having crossed two stable autos ( in fact 3 famous feminised strains with a less well known males from regular auto seeds), I want to use the F1 generation to back cross with another feminised mother from the same famous strain, so as to take the BC1 generation a step closer , and repeat with each BC generation until I was back to approx 90 % of the original feminised strain, only with a twist of a different classic thrown in hopefully for the better.
Oh boy, I got some trichome infused oil kicking in, so I better stop now before I bore the pants off you.
See ya.
PS, still haven't googled Dina Browning.