Inheritance of the bd allele

Hi, is anyone familiar with the inheritance of CBD producing alleles? The trait is co-dominant with the bt allele for THC, right? As I've gained a more in depth understanding of inheritance I've realized I may not have this thing figured out as well as I had hoped.

Lets run a hypothetical scenario. I cross strain A, a homozygous THC producing plant (bt/bt) with strain B, a homozygous CBD producing plant (bd/bd).

The F1 will have both co-dominant alleles and has an intermedite genotype (bt/bd), producing both THC and CBD in roughly equal proportions.

In the F2 you will get all the combinations from bt/bt and bd/bd to bt/bd and everything in between.

How about when I cross the F1 bt/bd chemotype plant with a high THC bt/bt plant? This is where I may have got it wrong.. Can I expect to find CBD producing plants in the F1?

What is the rough estimate on the % of bt/bd plants in the first generation? For bd/bd plants that should be 0, right?

Thule said:

How about when I cross the F1 bt/bd chemotype plant with a high THC bt/bt plant? This is where I may have got it wrong.. Can I expect to find CBD producing plants in F1?

What is the rough estimate on the % of bt/bd plants in the first generation? For bd/bd plants that should be 0, right?

Click to expand...

The cross in bold yields 50% CBD producing bt/bd and none of the bd/bd genotype.

Does this help?

Natural high said:

The cross in bold yields 50% CBD producing bt/bd and none of the bd/bd genotype.

Does this help?

Click to expand...

That helps a lot, thanks!

If others concur with this I now have a much better understanding of some crosses I may have hypothetically made or could make.

Thule said:

That helps a lot, thanks!

If others concur with this I now have a much better understanding of some crosses I may have hypothetically made or could make.

Click to expand...

If you just combine your genotypes using a simple punnett square you can't go wrong.

Cheers

Hi I have read when you cross Bt and Bd plants the hybrid Bt/Bd (or Bd/Bt) usually produces some more CBD than THC.

Eletta Campana Italian hemp.
https://encrypted-tbn0.gstatic.com/...ooYVEAYb3E39si9gnMCG0Ex1nVI9g0kdtKjXf9651Shjw

RSC Lebanese female outdoors with nice thick buds. Preliminary testing indicated CBD 4.2%, THC: 1.8%, CBDV: 0.2%, CBC: 0.1%.

Click to expand...

https://www.icmag.com/ic/showpost.php?p=8094196&postcount=8

If you do a backcross Bt/Bd (F1) x Bt/Bt (P1), you should expect 50% Bt/Bd and 50% Bt/Bt plants.

As CBD plants usually came from hemp genepool backgound, they are not selected for cannabinoid production. So they will make your plants produce a lower amount of cannabinoids. So even if you isolate a pure THC (Bt/Bt) female in the backcross its THC % surely will be lower than in the parental P1 psychoactive THC strain.

Greeting my friend

Most of it rings a bell, I just hadn't realized the allele gets passed on at such a high %. Must have gotten that misinterpretation from doing all those auto crosses where the autoflower trait is gone after the first backcross. That gene of course is recessive, in contrast to what we're discussing here.

My conclusion is that there's a 50% chance I have elevated levels of cbd on my receptors right now.

ahortator said:

Hi I have read when you cross Bt and Bd plants the hybrid Bt/Bd (or Bd/Bt) usually produces some more CBD than THC.

Eletta Campana Italian hemp.
https://encrypted-tbn0.gstatic.com/...ooYVEAYb3E39si9gnMCG0Ex1nVI9g0kdtKjXf9651Shjw



View Image

https://www.icmag.com/ic/showpost.php?p=8094196&postcount=8

If you do a backcross Bt/Bd (F1) x Bt/Bt (P1), you should expect 50% Bt/Bd and 50% Bt/Bt plants.

As CBD plants usually came from hemp genepool backgound, they are not selected for cannabinoid production. So they will make your plants produce a lower amount of cannabinoids. So even if you isolate a pure THC (Bt/Bt) female in the backcross its THC % surely will be lower than in the parental P1 psychoactive THC strain.

Greeting my friend

Click to expand...

I dont think you can narrow it down to cbd alleles and thc alleles. Quite sure its more involved then 1 trait is cbd and 1 trait is thc. Your experiments may prove me wrong tho.

Breeding for high CBD low THC does not follow the easy mathematical rules.

Normally you won't find high CBD low THC individuals in F1.

This paper should shed more light on the matter:

The Inheritance of Chemical Phenotype in Cannabis sativa L., Etienne P. M. de Meijer et al

https://csatc.org/pdf-Scientific-Research/deMeijer2003.pdf

Have fun!