Minimum Breeding Pairs / Creating a Landrace

[shishkaboy]

Did "marijuana" evolve from hemp?

I think I remember hearing subcool argue that it would revert rather quickly.

I mostly agree with what Spacebros is saying but I am not really sure on that part.
What do you all think?
Is devolution even possible?

...Ftr, I thought if a human makes selections its a cultivar. Which would mean that those seeds that were spread around by humans long ago were selections made by them and that there really are no landraces. Just different looking groups of the same genepool.

Kinda like people ... and every other organism.

Question for Coughie.
What would happen if we moved an acclimated population or suddenly changed its environmental conditions?

 

[SpaceBros.]

Hemp was first, than drug. Well at least CBD (Bd) first than THC (Bt) genes. I'm not sure about the BO/Bo locus though.

Mother nature (environment) would be making the selections if there is no interference by man. How the seed stock came to a local environment (wind pollination, by man - intentional or accidental) is largely irrelevant. So landrace it is.

Yes we've all heard that drug cannabis will quickly revert to feral hemp if left alone. I don't see the mechanism however. What is it about high THC or high cannabinoid Marijuana that puts it at a selective disadvantage over low THC, low cannabinoid Marijuana? Also if the genes are not present for low THC, low cannabinoid Marijuana in the founding population it's going to take an extremely long time for a random mutation to hit the relevant gene loci. But yes it can technically "de-evolve".

 

[shishkaboy]

How does this compare to other plants?

If we grow cabbage, cauliflower, kale or broccoli and let it naturally select, will it revert to the wild mustard?

 

[Coughie]

Did "marijuana" evolve from hemp?

I mostly agree with what Spacebros is saying but I am not really sure on that part.
What do you all think?
Is devolution even possible?

That's the theory, that 'marijuana' evolved out of selections made from hemp plants..

The 'de-evolution' is tied to early flowering males. It's said that when you're selectively breeding Cannabis, that you want to toss any males that flower in Veg, and any males that flower, roughly, in ~the first two weeks of the switch to flower...

It's said that, essentially, you want those males that flower that third week of flower / last week of stretching (in the females).. This is largely because hemp genetics are believed to be tied to early flowering males.

Hemp is extremely prolific.

The theory stands that if you throw a bunch of seeds in a field.. They all begin to grow in the spring, the daylight hours change as summer equinox approaches and they begin to show sex - females begin to stretch and the hemp-heavy males will begin to flower.

The idea is that as soon as the females are pushing pistils, the males are already tossing pollen - so the females are pollinated as soon as the pistils are ready. The hemp-heavy males crowd-out any later flowering males by taking all the female pistils as soon as they're ready.

This keeps any late flowering males, the minority, because by the time their ready, pollen has already been flying for weeks and a majority of the seed sites are always taken with hemp-heavy (genetically) pollen.... I've over exaggerated the hemp-heavy part here, to make it easier to understand, but it would be a 'slower' process... Taking maybe a decade, instead of 2-3 years....

But over successive generations, these earlier-flowering males from the "first generations" have a larger impact on the seeds / following generation... making for more early-males than in the generation before, exacerbating the issue exponentially, year by year. It wont take too long before 'late flowering males' are a thing of the past, and have no chance of any success due to the rise in early-flowering male population.

I don't have firsthand experience with this, that's why I'm full of "theory" and "the idea is" statements.. But this is supposedly the first steps towards the de-evolution of Cannabis back to hemp. I've read enough though, that I trust the theory. The little that I have seen, supports the theory, but I havent personally devolved cannabis into hemp (doubt any of us have though~)

 

[Coughie]

Question for Coughie.
What would happen if we moved an acclimated population or suddenly changed its environmental conditions?

It would depend on 'which way it went'.

A short-flowering variety, put into a long-flowering situation, or a long-flowering variety put into a short-flowering situation.

The long-flowering variety in the short-flowering situation is going to be a more dramatic experience than vise-versa.

Only the quickest finishers would stand a chance at maturing... The next generation would depend on the earliest flowering males hitting the earliest pistils, as soon as possible, to have the 5 weeks needed to make mature seeds. If the season shut down before then, the patch is dead.

The females would probably have a lot of bud rot from the rainy seasons coming before the plants were finished - meaning the plants are still going to attempt to stand strong until frost kills them - the time between when rains start & frost hits = moldy bud season.

The next generation that started the following spring, would be a product entirely of those early-flowering males on those first-emerging pistils. Everything else would be, theoretically, wiped out of the genetic pool. The females would have their influence because they were pollinated but only the males that tossed pollen in the 'new' growing season would provide the other genetic-half.

Successive years of this treatment is going to align those plants with that growing season, with these males having dominant effects on later generations of males.

The females that finish in the best conditions, that handle the new environment the best, that have the least amount of budrot, will also be the females that in turn, have the highest ratios of viable seeds.

So the females that handled the conditions the best, coupled with the males that flowered in time, make for the next generation.


Going the 'other way' is less clear-cut.. Every female has time to finish, every male has to time to shed pollen (but the earliest males still win the race).. The females all have ample time to finish the seed, and maybe even remain standing after, allowing the seed that can (the last to be pollinated, on the outer perimeter of the buds) to fall out naturally and possibly even begin growing before the mother plant actually collapses (tropical/no frost situation).

 

[Betterhaff]

...meaning the plants are still going to attempt to stand strong until frost kills them - the time between when rains start & frost hits...

What about when there is no frost?

 

[Coughie]

Well, there would be some sort of 'end' to the growing season.. May not be frost, but may be months-on-months of rain... There's an end to the growing season in most parts of the world, that *dont fit the opposite example* of being in somewhere tropical, where the plants would fit into the last paragraph...

If that doesn't hold true, then you probably didn't move the plants from one environment to another, that was drastic enough to warrant the original question - "What would happen if we moved an acclimated population or suddenly changed its environmental conditions?"

 

[shishkaboy]

Ok, so what if we took 2 landrace varieties that dont have enough difference in altitude or humidity and swapped them out.

I am basically asking of a Columbian landrace moved to jamaica, would there be a noticeable difference between the newly imported Columbian plot and the original Jamaican landraces?

Or would this create a new second Jamaican landrace?

Sorry for all the noobish questions but the topic is rather interesting. Makes me wonder.

 

[Coughie]

This would mean you're growing Colombian in Jamaica... Doesn't make the Columbian, Jamaican. You'd probably harvest some killer Colombian.

The differences between Jamaican and Colombian would still exist - the genetics are different. The environment would be the same, but the bud would what the bud was supposed to be - Jamaican in one, Colombian in the other.

 

[SpaceBros.]

@Shishkaboy
In regards to landraces moved from one region to another. Over long periods of time one would imagine that the Colombian becomes more like the Jamaican since the genes expressed in the Jamaican are likely to be more favorable for that climate. If those genes are at all present in the Colombian albeit at differing gene frequencies they should become prevalent. It will eventually become a second Jamaican landrace if kept isolated for a long period of time (without intervention by man and out-crossing to the original Jamaican landrace population) and significantly different to the founding Colombian stock. Some people even suggest Panama Red is just Colombian Red grown in Panama.

@Coughie
Any journal articles suggesting early flowering males traits are in Linkage disequilibrium (LD) with Hemp traits? Any ideas which loci are involved? Or just anecdotal evidence?

SB

 

[Tonygreen]

I think a lot of guys here are thinking on too small of a timescale.

Just because it is cannabis doesn't mean we get to redefine the definition of landrace.

Man had his hand in domesticating everything we call landraces just over periods of time longer than a few years or decades.

If you can get your kids and grandkids and their grandkids etc etc etc, to work the same line in the same environment for a few hundred years you will be on your way!

 

[Coughie]

@Coughie
Any journal articles suggesting early flowering males traits are in Linkage disequilibrium (LD) with Hemp traits? Any ideas which loci are involved? Or just anecdotal evidence?

SB

Purely anecdotal, at the moment.

I don't have firsthand experience with this, that's why I'm full of "theory" and "the idea is" statements.. But this is supposedly the first steps towards the de-evolution of Cannabis back to hemp. I've read enough though, that I trust the theory. The little that I have seen, supports the theory, but I havent personally devolved cannabis into hemp (doubt any of us have though~)

I do have research which may pertain to the question at hand, but I have not had the time to get into it, as deep as I'd like to, yet.

 

[Payaso]

I am enjoying the discussion, but pointless name calling and disagreements over verbage are boring, so I cleaned up this thread a bit.

Further bickering would result in the thread being closed... if you aren't interested please move along.

 

[stoned-trout]

I tried letting some sk1 go wild once...made it 2 seasons then died off.....interesting subject..yeehaw

 

[igrowone]

seems like the number should be 42

 

[Betterhaff]

- "What would happen if we moved an acclimated population or suddenly changed its environmental conditions?"

I just grow what I have in the environments I’m able…do the best with what I have. As far as the original question…natural selection is what is taking place.

Maybe I’m wrong but isn’t Cannabis an annual?

 

[stoned-trout]

the magic numb er is .....yeehaw

 

[rykus]

As an interesting side note, all the stories of the really well acclimatized out door strains from my local area( Texada Timewarp and Lasqueti Mighty Mite) where collaborative efforts by locals coming together to plant large "decoy" crops during prohibition years.

Basically the theory was the cops were going to fly no matter what, and the amount they flew depended on forest fires and funding by the big wigs back east..... So all the hippy grow communities knew that the local pork dept. would be proud to haul in a big huge # pile in their chopper net so they would communally go plant a huge stand together and use it for breeding or just a big bonus cut for everyone if they didn't find it.... But basically drew the eye away from all the productive individual gardens. Anyways after many years the local strains that people brought back or crossed in evolved over the years through conditions and selection into some of the most specific breed types and strongest plants I've seen or heard of.

Not sure if that helps or not and I wish I could add more specifics but it was before my time, but IMO those are landrace strains almost,lol.... If it breeds true and strong and is developed and adapted to local seasons and could survive with minimum input.... The hash farmers still worked those strains in the mountains and selected seed ect, as I'm sure some plant admiring Sumerians must have done when they were throwing colas on the embers in their tents, lol wouldn't you look for the crazy crystal coated purple ones.....

 

[BigNoise]

Thanks for all the input gents!

That's cool info about those BC strains rykus.

 

[kopite]

How many unique individuals would one need to start with to create a population with sufficient genetic diversity to avoid deleterious inbreeding?

One of my long term goals is to create a living seed bank, acclimated to the local conditions, which I and future generations could then harvest, or use as breeding stock in crosses. Basically, like how most long standing cannabis growing regions/cultures (India, Morocco, Jamaica, etc) do it.

From a mathematical view and with a view to avoiding inbreeding depression if we were to assume allele frequency to be 0.05 and were to assume 150 loci then if we aimed for 90 to 95 probability of capturing all, you would be looking at maintaining about 160-210 plants that would restrict inbreeding to about 1 per cent and avoid any depression. Obviously if you wanted to keep the rarest alleles you'd need higher numbers these numbers are allowing for loss within the population.
I think off the top of my head you'd be needing around 1000 to 1100 plants to keep all. (I remember the number of 2000 from SamS/RCC and think they got that from the hemp breeder (ref J crossa)