Genetic Drift..Population genetics.. mutations..

[Texicannibus]

Rick what do you think causes the mutants seen in some of DJs lines?

 

[englishrick]

its because Dj is the king of 1:1 matings while filial breeding.

The mutant factor comes from DJ never outcrossing his work and using too many already inbred 1:1 matings. If for several generations you cross all your already half sib plants to a single male, big surprise, you get a seedlot that lacks vigor and has accumulated deleterious recessive genes. Combine that with sample sizes of less than 50 plants and you're ganna run into problems. It's pretty hard to properly maintain germplasm when your breeding in a trailer park. He never put colchicine on his seeds. Don't believe the hype, but if you don't believe what I say feel free to pm and ask him.

 

[Dr_Tre]

great list. is adaption the same as acclamation ?

Adaption is for short period of time, while acclimation is for longer periods, over one generation.For example, you can adapt for drop in the night temps but you can acclimate for cold northern climate.

 

[indifferent]

The mutations in Dj's lines come from the Oregon Purple Thai he used. Probably the small populations he used in his selections meant it was hard/impossible to breed out all the mutations.

Genetic drift is caused soon as you take a P1 or any F1 seed or cultivar out their comfort zone,,, where it was bread or how it was bread these need to be followed through in subsiquent generations..

Er, no, not at all. Genes do not change unless an external mutagen such as a virus alters them. You need to grasp the difference between genotype and phenotype.

phenotype = genotype + environment

phenotypical expression changes due to changes in the environment, the genotype doesn't change unless a mutagen is at work.

 

[DocLeaf]

phenotype = genotype + environment

phenotypical expression changes due to changes in the environment, the genotype doesn't change unless a mutagen is at work.

This is how we understand it also

1000 growers may all have exactly the same clone,, but each will grow into a slightly different plant.

N.B. The term "pheno" is complete BS (it's never used in horticultural colleges),, and thus confuses the word "specimen" in observation ,, (which is a credible horticultural term).

Hope this helps

 

[indifferent]

phenotype isn't bs, it just gets mis-used as a term. People forget that the environment plays such a big part in phenotypical expression. If I have a cutting, say Cheese, and I give it to you and you grow it, you have the same specimen but a different phenotype because your environment isn't precisely identical to mine. People mis-use phenotype and use it to define a specimen, but it doesn't make the term phenotype bogus in any way.

 

[kopite]

its because Dj is the king of 1:1 matings while filial breeding.

it had the mutant factor before Dj did any work with it, so its nothing to do with 1:1 matings or such like,, as indifferent says its inherent to OPT or PT whichever you prefer it called. DJ has stated it could be down to colchicine but he didn't breed it he just used it..

Kopite

 

[indifferent]

.. dude,, you dont want beef with us! ...trust us about that,, cause we'll murk you like we murked the last man - DocLeaf Internet Gangster

Hahahahahahahaha absolute classic, i hope you've moved house, obtained a new id and had a wide range of cosmetic surgeries just to ensure you're safe from a murking!

Actually, isn't a murking one of them wigs ya wear on ya fanny?

Pmsl

 

[englishrick]

i cant be in a disscution like this now,,,

 

[indifferent]

This murkin business sound nasty, I wouldn't want anyone doing anything like this to my pubes!

Although I hear kopite's got lots of backup:

Looks like there's not been a lot of genetic drift amongst the LFC fans, I can see at least one trait that's definitely true-breeding among em! rofl

 

[kopite]

Ok I think alot of people have questions about these topics and the threads and answers regularly get spread out about on threads. Would be nice if we could have one large discussion about population genetics, genetic drift, and genetic mutation.

Im no expert but quite interested have been reading a good deal and have a few questions about them and there effects on cannabis.

I know this is a common question but to avoid genetic drift what would most of you say is a stable breeding population? Is it possible to nail down traits (allele frequency) and not risk genetic drift?

How common is genetic mutation? DJs blue berry often tosses mutants is this from a genetic mutation or is it a trait?

Hopefully people with the knowledge about genetics, populations, and how they relate to cannabis will chime in here. I would love to understand this all better.

Thanks to anyone and everyone who may contribute.

(disclaimer:noob)

It is not possible to prevent genetic drift. Genetic drift is simply random changes in gene frequency that occur because of sampling error, and the only way to prevent sampling error is to have an infinitely large population which is impossible. So you need to have work out approx the number of alleles you think should be saved or calculated to be saved usually calculating the polymorphic genes ie 2 or more alleles exist the frequencies given for this could be ≥0.01 (q), now you cannot save 100% to my knowledge though you can calc to 99% statistically using probability levels (p) (typically 0.01 or 0.05), so the probability of saving an allele could be said to be 1.0 - the probability of losing the allele. You NEED a breeding plan to be begin with !!

if we aim for 10 generations you need the Ne number per generation with the aim of retaining 95% of alleles.

You want to save alleles whose frequencies are 0.01 (q), and you want a 95% guarantee of saving the allele (P = 0.05) after 10 generations (when the 10th generation is produced). What constant Ne is needed to achieve this goal?

Step 1: Calculate the guarantee per generation that is needed to produce a 95% guarantee after 10 generations:

0.95 = (guarantee/generation)10

guarantee/generation = (0.95)1/10

guarantee/generation = 0.994883803

(0.95)1/10 can be determined by using the “yx” button on a hand-held calculator.

Step 2: Calculate the probability of losing the allele per generation:

Probability of losing the allele/generation = 1.0 - guarantee of saving it /generation

Probability of losing the allele/generation = 1.0 - 0.994883803

Probability of losing the allele/generation = 0.005116196882

Step 3: Calculate the Ne that is needed to produce a P = 0.005116196882 when q = 0.01 (the frequencies of the alleles you are trying to save):

P = (1.0 - q)2Ne

0.005116196882 = (1.0 - 0.01)2Ne

To determine Ne, the formula must be converted to logarithms. This can be done by using the “log” button on a hand-held calculator.

log 0.005116196882 = log(0.99)2Ne

log 0.005116196882 = (2Ne)(log 0.99)

524.89 = 2Ne

262.45 = Ne

Ne is rounded to the next higher whole number, so an Ne of 263 is needed every generation in order to produce a 95% guarantee of saving an allele whose frequency is 0.01 when the 10th generation is produced.


this was taken from a fish breeding program... I'll lok at notes to see which and post up link.

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again with regard to mutations, they can lead to lost alleles being recovered

Kopite

 

[indifferent]

Christ, I won't pretend I fully understood that post but I will try to absorb it, I guess the crux of the matter is that locking down an allele requires carefully considered breeding steps and decent sized populations for selection?

Hehe, arse-hair beard sounds ummm, whiffy! lol

Glad you liked the pic, it made me chuckle.

 

[DIGITALHIPPY]

This is how we understand it also

1000 growers may all have exactly the same clone,, but each will grow into a slightly different plant.

N.B. The term "pheno" is complete BS (it's never used in horticultural colleges),, and thus confuses the word "specimen" in observation ,, (which is a credible horticultural term).

Hope this helps

aslong as you are saying one genotype can have multiple specimens.
is it a terminoligy issue here?

i dont understand why i can have a pack of 11 ak47(example) and can get 11 different specimens...
specimen=/=genotype but genotype == specimen ?

ive seen alot of plants that "are the same but different" with attributes that cannot be explained by environment.

 

[Texicannibus]

You guys been busy thanks for the info might have to read it a few times. Kopite I understand that its impossible to assure that genetic drift wont happen. I guess the question I had was more to do with what would be considered a proper size breeding population to lessen the likliness of drift.

 

[kopite]

Christ, I won't pretend I fully understood that post but I will try to absorb it, I guess the crux of the matter is that locking down an allele requires carefully considered breeding steps and decent sized populations for selection?

Hehe, arse-hair beard sounds ummm, whiffy! lol

Glad you liked the pic, it made me chuckle.

Yes for instance if you start at generation 1 you require 150 plants to retain 95% at a f level of 0.01 so even if the f parameter is moved to 0.1 you still require 15 plants to attain this level.... hence many things are lost before people begin.

Kopite.

Ps it seems you cannot have sigs that upset the cart here... censorship at its best....

 

[N. Accumbens]

....

....

Landrace stock picked by hand off a larger tree like sativa growing in the himalayan mountains... many of the seeds hold what we call "mutated" genes- but they may just be touched by the heavens at those heights~~~ since they are unlikely to be have been bred by anyone but nature- even nature likes special and different-

KA~

 

[Texicannibus]

Special and different I believe is generally regarded as evolved atleast if its to a benefit. The gene that causes the mutation in DJs plants could arguably be evolved cannabis imo. Since Ive never grown out one of these mutants Ill leave that to those that have.

So my question really isnt whats the statistical number (ne) of plants is necessary to make genetic drift unlikely, but rather how many plants do you guys with experience think you need for a reasonable breeding project without likely genetic drift. I know that statistics seem to play a large roll in determining numbers but Im asking more for rl experience.

A new question I have is ... do we know exactly how diverse cannabis is relative to other things... In other words do we know how many alleles is in say fish compared to cannabis.

Edit: I should add that Im not sure alleles is the proper term for what im trying to say. Im just asking do we know how diverse cannabis is genetically in comparison to say fish...

 

[Texicannibus]

It seems to me that different species of both plants and animals respond differently to genetic drift. In addition it seems that both stressful conditions and selection could help deter genetic drift. Im not sure how selection and conditions are playing into that algorithym... or are they even?

 

[hoosierdaddy]

I want to offer up a couple shots of freshly rooted clones.
Both are from the same plant, cut same day, same bubbler, etc...only difference is container. Same medium, same water, etc...
One has what I have always called a "stress mutation", however it seems that this sort of a stress response is in reality not a mutation, per se.
Not sure what, but something triggered a response in this clone. Maybe I hit it with the wrong feed and it was too hot...dunno.
Also note that the healthy clone has had a slight touch of mite damage, which I have treated...but the other clone has not been touched at all by the first mite.

What I am seeing here is more than likely "epigenetic response" to a stress, yes?

 

[Texicannibus]

wow similair to a reveg freak wish you had a better idea what caused it but thanks for sharing bro

Btw I agree epigentic response ... although im a noob on this stuff still.