Genetic Drift?

[LoudBlunts]

It could have been the nutes as well mate. I know from past experience, especially with 24h light schedules that once fluoro bulbs start to get old plants start to flower. I posted about this like 6 years ago and an old member(Caprichioso I think) told me that my bulbs were old and that the frequency drop can be "seen" by the plants even though I couldn't with my naked eye. I changed to new bulbs and kept up with a regular schedule of changing them out(8 weeks at the most) and noticed that the auto-flowering stopped. I also dropped my light schedule from 24h to 18h. Once again I was told by an old member that the 6 hour darkness is to give the plants a rest period. I am not saying it does anything or not but I did notice the plants grew faster with a dark period. I am sorry I cannot cite any of my sources, I am not even sure if the threads are even around anymore. Hopefully this can help clarify where I am getting my info from.

We can only say what we think it could be and narrow it down to the most likely causes. Will we ever know for sure what it was? Probably not because there are so many factors to involve. The only one thing that everyone can agree on is that stress caused it...but what caused the stress? As far as why your specific plant did this, it was definitely genetic because no other strains did it. It was definitely light stress, bulbs were old, and it could more than likely also be the nutrient hit. There could have been other factors but the main ones IMHO(it's not gospel) are genetics and the light stress. I have never really heard of a plant flowering from getting too much nutrients...although I am not doubting it can happen, I've just never experienced it myself.

thanks again

 

[kopite]

The current understanding is that whilst epigenetic effects do not encode themselves in the underlying DNA, they can exert an effect for many generations of cell divisions (so relevant to clones) and occasionally transgenerationally (as in studies that show that parents exposed to starvation conditions produced offspring acclimatized for conditions of scarcity) So as far as we know, No epigenetic effects are not permanent. Sometimes lasting, but not pemanent.

Cheese seems to me to be just another Skunk plant, with a heap of hype. The only thing that distinguishes it is a strong smell. I doubt this is the result of a novel genetic mutation or an epigenetic modification. But who can say? Only way to know is to study the genomes of the vast plethora of cannabis varieties and compare.

I think Grat3fulh3ad has given the OP the best answer they'll get

KOPITE:
Epigenetic changes are heritable but reversible.

thanks for the reply, I understand about the effects being able to be passed though not lasting, a good example being vernalization.

Re: Cheese, from what I gather the "cheese" grew like a skunk then changed for no apparent reason, i have been thru many many skunks and not found anything like the "cheese". now if its epigenetics at play and its adapting to an enviroment, we should see the "cheese" start to change again after time shouldn't we?

As far as what the OP saw, he stated it came out of nowhere. To me that is not indicative of a drift, but rather a reaction to some sort of stress

thats how I see it, it happened fast, TMK drift does not happen fast.

On the scale of a single organism changing in different environments , the heritable changes are almost always epigenetic. On the small scale of a few generations of a series of clones of clones epigenetic response is the vehicle for adaptation... or epigenetic response is adaptation.

In the OP's case probabilities lean really hard toward epigenetic changes.

I understand this and to me it has been seen with acclimitised landraces..

If maintaing the 'degraded' cut in a healthy environ and only cloning the healthiest portion of the plant brings it back to the original state from the 'degradation' then it was epigenetic. If the degraded clone remains poor, then there was a mutation.

well something here doesn't stack up!!! on the one hand you say the change is heritable however you then say if it changes back its epigenetic??? surely if the plant has gone thru an epigentic change though its gentic code stays the same the ONLY thing altering it is the enviroment? which is the only thing that changes with acclimitised landraces... it is just adapting to its enviroment... however if it has been affected by epigenetics then why would it change back if it has adapted to the enviroment it is now in ?? the only reason for another change would again be a change in enviroment would it not? it would be interesting to see if the OP had the original mum and how the clones would be compared to how the clones from the cloned plant looked.

Kopite

 

[Jones]

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[furious george]

well something here doesn't stack up!!! on the one hand you say the change is heritable however you then say if it changes back its epigenetic??? surely if the plant has gone thru an epigentic change though its gentic code stays the same the ONLY thing altering it is the enviroment? which is the only thing that changes with acclimitised landraces... it is just adapting to its enviroment... however if it has been affected by epigenetics then why would it change back if it has adapted to the enviroment it is now in ?? the only reason for another change would again be a change in enviroment would it not? it would be interesting to see if the OP had the original mum and how the clones would be compared to how the clones from the cloned plant looked.

Kopite

Not sure what doesn't stack up for you. You certainly understand all the key points.

Epigenetic changes can be heritable yes, but they are not permanent. If the problems/changes encoutered with a strain reverse (over time) when environmental stresses are removed then this would indicate that the initial deviation from 'normal' growth was caused by epigenetic influence. The adaptation of a plant to a new environment is mediated by epigenetic factors switching on or off elements within the plants genome.

The difference between 'Cheese' and other skunk 1's in my view are due to it being a rare combination of Sensi's old Skunk 1 parental genetics. If the difference were due to epigenetic changes, then given the huge number of times this has been cropped over the last 20 odd years, in millions of different grow rooms, many of the clone lines would by now have reverted to their original form. I therefore believe that the 'unique' traits of Cheese are down to nothing more than lucky recombination of the parental genes.

EDIT: Re Jones post. Interesting stuff. It might be worth noting that varieties of cloned grapes can be very old indeed. For example Zinfanfel grape vines stem from an original grapevine from the 1700's. The timescales involved in vine cultures provided an appropriate timescale for true mutations to creep in.

 

[kopite]

Not sure what doesn't stack up for you. You certainly understand all the key points.

Epigenetic changes can be heritable yes, but they are not permanent. If the problems/changes encoutered with a strain reverse (over time) when environmental stresses are removed then this would indicate that the initial deviation from 'normal' growth was caused by epigenetic influence. The adaptation of a plant to a new environment is mediated by epigenetic factors switching on or off elements within the plants genome.

The difference between 'Cheese' and other skunk 1's in my view are due to it being a rare combination of Sensi's old Skunk 1 parental genetics. If the difference were due to epigenetic changes, then given the huge number of times this has been cropped over the last 20 odd years, in millions of different grow rooms, many of the clone lines would by now have reverted to their original form. I therefore believe that the 'unique' traits of Cheese are down to nothing more than lucky recombination of the parental genes.

EDIT: Re Jones post. Interesting stuff. It might be worth noting that varieties of cloned grapes can be very old indeed. For example Zinfanfel grape vines stem from an original grapevine from the 1700's. The timescales involved in vine cultures provided an appropriate timescale for true mutations to creep in.

the point I was trying to make was that if one is affected and the other isn't yet they are the same age wise and genetic wise, they why would they be different? why is one having its modifers turned on/off and the other not? surely something has affected one and not the other?

The point on "cheese" was it was stated that the clone changed dramatically almost overnight as seen with other clones and with the OP's clones.. before that it was just like a reg skunk... those that have selfed it TMK found it not to be homo ... so A) why did it change? B) how did it change? it should also be noted that some have said it has also deterioated

looks to me like the change was perm or we would see it revert it has been in many diff enviros like you state !!!

Kopite

 

[furious george]

Sorry I'm slightly confused. I thought Head was suggesting a method of determining whether the changes were epigenetic or not, by culturing the 'degraded' and 'normal' cuts in the same environment and observing whether the 'degradation' reversed over time. What you seem to be asking is why would one of two identical clones in identical environments change/degrade. I don't see where that applies. Perhaps I should come back to this with a clear head!

The point on "cheese" was it was stated that the clone changed dramatically almost overnight as seen with other clones and with the OP's clones.. before that it was just like a reg skunk... those that have selfed it TMK found it not to be homo ... so A) why did it change? B) how did it change? it should also be noted that some have said it has also deterioated

looks to me like the change was perm or we would see it revert it has been in many diff enviros like you state !!!

Kopite

Who stated it changed dramatically almost overnight? I think this story is nothing more than BS. It's just a standout Skunk plant. And after 20 years of cloning it's hardly surprising that "some" have said it has deteriorated. For some it certainly would have.

There are two ways of interpreting the fact that it hasn't reverted in the many different environments in which it is grown:
1) The 'Cheese' is the result of epigenetic change and that epigenetic change was permanent. Well we know this can't be the case.
2) The 'Cheese' has nothing to do with epigenetic modification and is just a favorable recombination of parental genetics.

I prefer explanation 2.

 

[kopite]

Sorry I'm slightly confused. I thought Head was suggesting a method of determining whether the changes were epigenetic or not, by culturing the 'degraded' and 'normal' cuts in the same environment and observing whether the 'degradation' reversed over time. What you seem to be asking is why would one of two identical clones in identical environments change/degrade. I don't see where that applies. Perhaps I should come back to this with a clear head!




Who stated it changed dramatically almost overnight? I think this story is nothing more than BS. It's just a standout Skunk plant. And after 20 years of cloning it's hardly surprising that "some" have said it has deteriorated. For some it certainly would have.

There are two ways of interpreting the fact that it hasn't reverted in the many different environments in which it is grown:
1) The epigenetic change was permanent. Well we know this can't be the case.
2) The 'Cheese' has nothing to do with epigenetic modification and is just a favorable recombination of parental genetics.

I prefer explanation 2.

or it wasn't Skunk in the 1st place... but yes 2 is the pref... the person who stated it changed dramatically etc was the said person who got it to "Exodus".

What you seem to be asking is why would one of two identical clones in identical environments change/degrade. I don't see where that applies. Perhaps I should come back to this with a clear head!

No I was stating Clone A: from original mum Clone (original unaffected) B: Clone off Clone mum (degraded) if both in same enviroment and same age etc why differ? what affected one and not other?

Kopite

Ps I will prob re-read thread myself to see if i'm reading it right.

 

[Grat3fulh3ad]

well something here doesn't stack up!!! on the one hand you say the change is heritable however you then say if it changes back its epigenetic??? surely if the plant has gone thru an epigentic change though its gentic code stays the same the ONLY thing altering it is the enviroment? which is the only thing that changes with acclimitised landraces... it is just adapting to its enviroment... however if it has been affected by epigenetics then why would it change back if it has adapted to the enviroment it is now in ?? the only reason for another change would again be a change in enviroment would it not? it would be interesting to see if the OP had the original mum and how the clones would be compared to how the clones from the cloned plant looked.

Kopite

Epigenetic changes are temporary but heritable. They may last for only a cell division or two, or may last through multiple generations.

The epigenome turns genes on and off, based on stimuli/stress/environment.

 

[chef]

From what I've observed over the years, Raco nailed the cause & Head nailed the solution.

The cause is inferior clone material/stressed mother & the cure is taking healthy apical cuts of healthy apical cuts for a few gens. I've seen cuts go from peewee herman to hulk hogan in 2 gens flat.
I've always looked at it as promoting positive genetic drift?

It's really noticeable when cloning for a perpetual, as I have several gens in front of me for comparison.

my 2

 

[kopite]

Epigenetic changes are temporary but heritable. They may last for only a cell division or two, or may last through multiple generations.

The epigenome turns genes on and off, based on stimuli/stress/environment.

Agreed.

http://web.me.com/christinalrichards/Portfolio/Home_files/BTI knotweed.pdf

I just prefer it called Phenotypic variation. they are just adapting to the given enviroment/stress. or would you say epigenetics drives phenotype?

Kopite

 

[Grat3fulh3ad]

Agreed.

http://web.me.com/christinalrichards/Portfolio/Home_files/BTI knotweed.pdf

I just prefer it called Phenotypic variation. they are just adapting to the given enviroment/stress. or would you say epigenetics drives phenotype?

Kopite

Epigenetic response and phenotypical variation could be graphically represented as two circles which overlap. There is common ground, but there are epigenetic responses not readily noticeable in phenotype, and phenotypic variations which are purely the result of genotypical response. according to my understanding of the processes at work.

 

[hoosierdaddy]

Epigenetic changes are temporary but heritable. They may last for only a cell division or two, or may last through multiple generations.

The epigenome turns genes on and off, based on stimuli/stress/environment.

So, these shifts are totally stress/stimuli dependent?
Are you saying that there are no epigenetic mechanisms in play that are not stress related?

 

[kopite]

Epigenetic response and phenotypical variation could be graphically represented as two circles which overlap. There is common ground, but there are epigenetic responses not readily noticeable in phenotype, and phenotypic variations which are purely the result of genotypical response. according to my understanding of the processes at work.

With regards to epigenetics, chromatin structure and inheritable characteristics do you or anyone else think that with epigenetics at play you could specifically breed toward generations of plants able to withstand certain diseases.. sorry about going off on a tangent.

Kopite

 

[Grat3fulh3ad]

So, these shifts are totally stress/stimuli dependent?
Are you saying that there are no epigenetic mechanisms in play that are not stress related?

Stimuli dependent? yes, in that epigenetic changes do not occur randomly without cause.

I never said anything to indicate "that there are no epigenetic mechanisms in play that are not stress related".

With regards to epigenetics, chromatin structure and inheritable characteristics do you or anyone else think that with epigenetics at play you could specifically breed toward generations of plants able to withstand certain diseases.. sorry about going off on a tangent.

Kopite

In that the structure and functioning of the epigenome are the result of the underlying genome's program, you could specifically breed toward those goals, but determining the genetic/epigenetic origins of particular responses would be a lot more challenging than simply selecting disease resistant breeding stock, for example.

 

[englishrick]

@kopite,,,,

i think the Cheese has been stinky and afghan dom since day1,,

imo,,,, sensi change there P stock year to year,,,i bet the stock from 1989 was simply a good batch,,,,at some point that seed stock must have ran out,,,i do not believe for 1 second that they used the same males in later batches ,,,,an to be honest id be very supprized if they sensi kept sk1 mothers hanging around for 10years,,

i believe the blues clone is a sister to the Cheese,,,"same mothers",,,,once them skunk mothers were lost,,bye bye cheesey weed

ive smoked loads of Bluecheese [Cheese x DjBlueberry]and ive helped countless pees grow it an let me tell you guys,,,,the cheese`s Afghan/stinky traits shine through loud and clear!!!!!!,,,,,,,if it was an epigenetic effect that made cheese its fukin stablized through repoduction

 

[Grizz]

was it 50% that didn't root at all, or 50% of the cuttings were lacking in their veg/flower/smoking performance?

no they all root well, as greyskull said you can spot the dudds in veg, darker smaller leaves, brittle stems, everyone seems to suggest stress is the cause, but like i stated how could it be, 4 different growers, all getting perfect plants then all of a sudden all 4 growers are getting dudds,

 

[Grat3fulh3ad]

So you are getting good plants and duds off of the same moms?

Small dark leaves and brittle stems can be indicative of nute/ pH issues. Maybe that plant is really P and K sensitive?

 

[gdtrfb]

no they all root well, as greyskull said you can spot the dudds in veg, darker smaller leaves, brittle stems, everyone seems to suggest stress is the cause, but like i stated how could it be, 4 different growers, all getting perfect plants then all of a sudden all 4 growers are getting dudds,

wild - is this something ongoing, or have you/the other growers moved on to different cuts?

 

[Grizz]

yes, all of the same mother, same for greyskull and zoo. I had over twenty cuts all flowered in a prepetual system, ended up with 17 dudds, all fed the same nutes, same ph, sensi veg a &b sensi bloom a & b with overdrive. ph 5.8 to 6.2, I know zoo uses canna nutes and i belive greyskull does to. I could see if it just happened to my grow, but 4 different growers getting the same results, also have a friend thats running the same strain, his mom came from the same origanal mother, he hasent had any trouble with his yet.

 

[Grizz]

wild - is this something ongoing, or have you/the other growers moved on to different cuts?

i killed the dudd producing mom and got another cut from a friend that says his arent doing this, we will see soon as im taking cuts of it now.