Minimum Breeding Pairs / Creating a Landrace - Breeder's Laboratory - International Cannagraphic Magazine Forums

BigNoise · 01-11-2016, 06:49 AM

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.

MJPassion · 01-11-2016, 02:11 PM

Quote:

Originally Posted by BigNoise

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.

Please elaborate?
Are you asking about unique individuals within a given line or are you talking about mixing/crossing several varieties together?

Either way...
I dont think there is a definitive answer.
The more the better...

Chimera would probably be the best person to answer this anyway.

KiefSweat · 01-11-2016, 02:16 PM

for it to be heirloom/landrace i think you would want to open pollinate it with as many plants as possible, the idea is to keep as many genes as possible with selections you start narrowing down the genepool in the line

BigNoise · 01-11-2016, 08:53 PM

On one end of the spectrum, you would start with seeds from one plant. If you planted a few thousand seeds from that plant, and didn't allow any other plants to pollinate the population, eventually, you would start getting a lot of fucked up plants. Right?

The other end of the spectrum would be starting with some seeds from every source imaginable, basically a sampling of all the genetics on earth. This population wouldn't have any inbreeding problems.

Somewhere in between the two extremes, there is a minimum "chunk of the gene pool" that would allow a viable population to begin.

I am far from a botanist, but I know that when discussing fauna, "minimum breeding pairs" is a relatively common term. If this does not translate directly to plants, I would love for someone to educate me.

KiefSweat · 01-11-2016, 11:01 PM

i don't think inbreeding depression is as bad as some people make it out to be.
its more about diversity, a landrace will have a majority of the same traits and should be identifiable as a whole, but you may still have say purple plants or short ones in the mix. If you used seed from those ones alone you may only get short or purple plants in the future. It may take years for it to be so inbred that its not worth growing but you may never see a green plant again.

Tonygreen · 01-11-2016, 11:09 PM

I used to think a landrace would have inbreeding depression but it was explained to me that landraces are not homozygous they are heterozygous as such you dont see inbreeding depression.

I might have over simplified that answer but it seems to be what I recall being schooled on.

Dropped Cat · 01-12-2016, 01:14 AM

Quote:

Originally Posted by BigNoise

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

Many would argue that all landraces are "polluted" from
introduced genetics.

Maybe.

If you had such "unique individuals", to prolong a cultivar
one would start with plants numbering in the thousands.

Many breeders convince themselves this is not the case,
so align yourself with the views that best support your
plot size and time allotted to your project.

Keep us posted, we're all counting on you.

Good thread!

LostTribe · 01-12-2016, 05:36 PM

First of all you are not going to create any landrace strains because you are not the almighty creator of life.

As for breeding with landrace genetics you will find that it is probably dependent on the strain you intend to breed with. Although a good selection of plants really would be necessary to complete the task correctly. Some might say 10 plants while the minority of true breeders here would definitely say a great deal more. Even with todays mess of supposedly inbreed lines, truly most are not really considered IBL just because they were mixed with the same strain.

You should imagine the past outdoor growers whom kept their genetics going for centuries. You really would want plant numbers in the 100's if not 1000's or 10's of 1000's to properly make seed with all the true aspects of a specific variety of plant.

It is not just a one and done mixing of females and males. That is just a beginning as future generations must also be bred out in order to really create a real stabilized creation.

BigNoise · 01-12-2016, 10:08 PM

Quote:

Originally Posted by LostTribe

First of all you are not going to create any landrace strains because you are not the almighty creator of life.

Perhaps "create" is the wrong term. I guess it would be more "putting the pieces in place so a landrace can develop".

Landrace /= untouched by man, if that's what you're implying. How do you think Moroccan, Malawi, Mexican, Colombian, etc landraces came about? Any cannabis outside central/SE Asia was brought there by humans.

I mean, if for the rest of my life I sowed some surplus seed from my grows in the same area up in the hills, nobody else added any inputs, and nature took its course, at some point, those plants would become a landrace. Landrace implies a length of time where nature is the only selector.

I was just asking how big of a slice of the genetic pie one would need if they wanted to do a one-and-done planting to start a viable landrace.

MJPassion · 01-13-2016, 01:07 AM

I asked Chimera to stop in. Dont know if he will or not but I still stand on my first answer...

There is no definitive answer.

Are you going to include hemp?
There are literally thousands of varieties of drug types as well as fiber/seed types.

What really is your goal?
I believe an heirloom is something in the range of 20+ years of a particular variety being grown year to year from seed from the previous year.

Tossing a bunch of random genetics in a field to cross and collect and grow and cross and collect and grow and cross...
Does not a landrace make.

Why not select a landrace or few and see what, of them, can survive your particular area and maintain them?

01-11-2016, 06:49 AM	#1
BigNoise Member Join Date: Jan 2015 Location: Cascadia, the wet part Posts: 137	Minimum Breeding Pairs / Creating a Landrace 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.
	Quote 1 members found this post helpful.

01-11-2016, 11:09 PM	#6
Tonygreen IC Mag Supporter Join Date: Apr 2012 Location: dark side of the moon Posts: 8,226	I used to think a landrace would have inbreeding depression but it was explained to me that landraces are not homozygous they are heterozygous as such you dont see inbreeding depression. I might have over simplified that answer but it seems to be what I recall being schooled on. __________________ When The Green Drops The Bullshit Stops KNOWN BUBBLE HEAD
	Quote

01-12-2016, 05:36 PM	#8
LostTribe Senior Member Join Date: Jan 2015 Posts: 3,007	First of all you are not going to create any landrace strains because you are not the almighty creator of life. As for breeding with landrace genetics you will find that it is probably dependent on the strain you intend to breed with. Although a good selection of plants really would be necessary to complete the task correctly. Some might say 10 plants while the minority of true breeders here would definitely say a great deal more. Even with todays mess of supposedly inbreed lines, truly most are not really considered IBL just because they were mixed with the same strain. You should imagine the past outdoor growers whom kept their genetics going for centuries. You really would want plant numbers in the 100's if not 1000's or 10's of 1000's to properly make seed with all the true aspects of a specific variety of plant. It is not just a one and done mixing of females and males. That is just a beginning as future generations must also be bred out in order to really create a real stabilized creation. __________________ LostTribe Treating Cancer with Concentrates https://www.icmag.com/ic/showthread.php?t=301121
	Quote

01-11-2016, 02:16 PM	#3
KiefSweat Didn't See Me Comming Join Date: Dec 2011 Posts: 664	for it to be heirloom/landrace i think you would want to open pollinate it with as many plants as possible, the idea is to keep as many genes as possible with selections you start narrowing down the genepool in the line
	Quote

01-11-2016, 08:53 PM	#4
BigNoise Member Join Date: Jan 2015 Location: Cascadia, the wet part Posts: 137	On one end of the spectrum, you would start with seeds from one plant. If you planted a few thousand seeds from that plant, and didn't allow any other plants to pollinate the population, eventually, you would start getting a lot of fucked up plants. Right? The other end of the spectrum would be starting with some seeds from every source imaginable, basically a sampling of all the genetics on earth. This population wouldn't have any inbreeding problems. Somewhere in between the two extremes, there is a minimum "chunk of the gene pool" that would allow a viable population to begin. I am far from a botanist, but I know that when discussing fauna, "minimum breeding pairs" is a relatively common term. If this does not translate directly to plants, I would love for someone to educate me.
	Quote

01-11-2016, 11:01 PM	#5
KiefSweat Didn't See Me Comming Join Date: Dec 2011 Posts: 664	i don't think inbreeding depression is as bad as some people make it out to be. its more about diversity, a landrace will have a majority of the same traits and should be identifiable as a whole, but you may still have say purple plants or short ones in the mix. If you used seed from those ones alone you may only get short or purple plants in the future. It may take years for it to be so inbred that its not worth growing but you may never see a green plant again.
	Quote

01-13-2016, 01:07 AM	#10
MJPassion Observer Join Date: Dec 2012 Location: uni-verse Posts: 5,584	I asked Chimera to stop in. Dont know if he will or not but I still stand on my first answer... There is no definitive answer. Are you going to include hemp? There are literally thousands of varieties of drug types as well as fiber/seed types. What really is your goal? I believe an heirloom is something in the range of 20+ years of a particular variety being grown year to year from seed from the previous year. Tossing a bunch of random genetics in a field to cross and collect and grow and cross and collect and grow and cross... Does not a landrace make. Why not select a landrace or few and see what, of them, can survive your particular area and maintain them?
	Quote