Inbreeding.....the Skill of the Breeder.....

[Cuzin_Dave]

To expand on the basic concept of Ne one must consider how Ne effects the F statistic (Coefficient of Inbreeding).
So let's assume an NE of say 4. The decline in heterozygosity or rate of inbreeding at from the first generation would be: F1 = (1) / (2 * Ne) or 1 / (2 * 4) = .125.
With each subsequent generation the decline in heterozygosity is cumulative. Take generation F6
F6 = 1 - (1 - F1) ^ 6 = 1 - (1 - .125) ^ 6 = .551
By the 6th generation 55% of the genetic diversity will have been lost in the line. By the 12th generation 1 - (.87.5) ^ 12 = 80 % of the genetic diversity will have been eliminated.
The larger the Ne the lower the rate is the actual loss of diversity through inbreeding.

 

[Bass Akwards]

The Patience of the Breeder

The Patience of the Breeder

Any way you look at it, breeding is a time consuming project.

Even one small potted plant ( so to speak ) can, when pollinated, produce two 35mm film containers full of seeds.

How many seedlings can you handle at one time?

Finding special plants in a population that size takes experience, a good deal of luck, and a set of early selection criteria to thin the ranks prior to growing them out completely.

Like the old joke about Real Estate, there are three important things about breeding:

Testing, Testing, Testing.

Does anyone care to comment on line-breeding large numbers of siblings?

Are there viable alternatives to Vic's variation on RRS?

 

[CrystalsCrystal]

gotta love diversity.. im a human sampler platter.. african asian american and euro

 

[JITAMON]

Gotta say this. All the info so far is based off of SCIENTIFIC info. Where is the Mysticism factor? All the unexplained offspring? I have found the formulas for breeding presented on this site spot on, but there seems to be an over adjustment toward " science" and not enough mysticism. After all we are after the ultimate "high" with this plant are we not? I wonder how it all works together

 

[dreams]

Good info to know...

 

[IndianHay]

is it matter which strain is male or which is female? For example is any diffrence if i breed male big bud and female blueberry or female big bud and male blueberry?

 

[Colina]

It doesn't matter that I have seen. And I bet about 0.0000001 % of these math folk have stayed focused long enough on any single line to have much of a clue about inbreeding depression.. lol

 

[Bass Akwards]

It had been suggested, by Vic High and probably others, that crosses be tested both ways ... with both F x M and M x F ...

It was part of the "simplified" RRS model he published.

 

[kopite]

I think JLP did this with a cross of NYCD x C99 and vice versa called it Juliet?

Kopite

 

[Ganglere]

Great thread

Just thought I'd put in my on the subject of inbreeding in nature. Inbreeding is a very important factor in speciation, or the formation of new species. For one, inbreeding can lead to large(ish) restructuring of the genom, wich would with a great degree of certainty not be compatible with 'original' genom. This effect (regardless of degree of inbreeding,) could explain some of the cases of sterility. If these 'sterile' plant were to be bred with genetical siblings, the odds of sucsess would increase with increased genetical similarity.
In many cases, new populations in an area will be started by very few pioneers, this is especially visible on islands. These populations would soon (within x generations) accumulate so many detrimental effects that it might go extinct. Indeed, this has probably happened lots of times, but we only see what is, not what could've been.
But this is where selection comes in. In your garden, you try your best to select genotype based on phenotype, pretty difficult, at best.
Natural selectin, however, selects by more objective criteria. What matters here is relative reproductive sucsess. Let's say there is one genotype (A) that has a one % higher relative sucsess than it's rival genotype (B), and that this advantage is hereditary, than in a relatively few generations A would massively outnumber B.

This scenario is statistical, and does not include accidents or plain bad luck. If A has a nice set of feathers on it's head, while B does not, then this could potentially confer more matings for A. But if some crazy Europeans wants to wear said feathers in their hat, this could make B the sole survivor.
The detrimental effects of inbreeding can be held back by the effects of natural selection. Physical abnormalities almost inevitably lead to lower 'fitness', in effect lower relative rep.sucs. If half your kids get eaten before they reproduce, that's pretty good results in this cruel world. But bad alleles (version of gene) would in a situation of great selective pressure be increasingly rare as their carriers lose the statistical race, or simply gets eaten. Obviously, for the avid gardener, this is not a blueprint. What get selected for in nature is rarely what we want selected for. But nature can show us and we can tweak


To try to summarize, artificial selection upon inbred lines require a great number of 'selectees', and would in a perfect world involve genotype/phenotype-selection, as mimicking natural selection. As this is hardly practical, the phenotype-selection needs to be made according to empirical, objective criterias. There should also be an ever expanding list of reasons to cull. That 50% from one ancestor is well worth remembering.
Inbreeding should not be done to much, and if done, done carefully and documented. Seed strains need the dynamics of a vibrant and varied genepool to stay vibrant. If you can't achieve this, then outcrossing is required. Hybrids are the only way except cloning that combines uniformity and vigour, and the stabilizing of parent strains(PS) should be done carefully. When you find good PS that fulfills your requierements, keeping these as clones is the ONLY way to get the same f1 hybrids more than once. Seed- siblings of your fine parents could also be kept for extended periods, but unless really inbred or selfed, the resulting f1s would not be identical to earlier seeds. This would apply to other generation crosses also. However, difference could vary from none to significant, and breeders can and do get great results this way. But the bottom line for all life is to change or die, and to try to keep a seed strain static, so there will be a point of trade-off between the different thraits selected for, and the problems assosciated with diminishing genepool diversity, vs stability and vigour.

This fast reply of mine after reading the thread became a little messy, due to somebody smoking some good breed, maybe I'll clean it sometime..

Finally, I have an idea I think might be fun to try; When a plant with exceptional potential in breeding/seed production has been identified (with cloning), it is selfed, and following generations selfed etc, untill problems occure. Problems would thus be identified, and compatibility charts could be made for the fine ibl-clones considered for crossing. By thus pressing a clone's selfed line to the edge, one could learn alot about genotype. Then one could try diff crosses and see wich give best results. With good book-keeping this should work out splendidly, but does require space and a somewhat nerdy approach.

I've got heaps of experience in both paticipating in and running field tests of legal crops, even though as of yet none with mj. In my experience, the absolute number one thing is stringent guidelies, and NO slacking on the documentation!! Experimentation without documentation is like putting our willy into the lawn mower. Only dumber

Jeez, I need to learnme self control

Peace, G

 

[StrillaGuy]

Many, many years ago when I was just twenty-three,​

I was married to a widow, she was pretty as could be.​

This widow had a grown-up daughter who had hair of red​

And my father fell in Love with her. Soon they too were wed.​

This made my dad my son-in-law--changed my very life!​

My daughter was my mother because she was my father's wife!​

To complicate the matter even though it brought me joy,​

I soon became the father of a bouncing baby boy.​

My little baby he then became a brother-in-law to Dad.​

Well, that made him my uncle--made me very sad!​

Because if he was my uncle then he also was a brother​

To the widow's grown-up daughter, who, of course, was my stepmother.​

My father's wife then had a son who kept them on the run.​

And, of course, he became my grandchild because he was my daughter's son.​

My wife is now my mother's mother and this makes me blue​

Because although she is my wife, she's my grandmother too!​

Now if my wife is my grandmother, well, then I am her grandchild,​

And every time that I think about this, it nearly drives me wild!​

Because now I have become the strangest case that you ever saw​

As husband of my grandmother, I’m my own grandpa!​

So I got my interbreading plan... sound good as any! Thanks

 

[azad]

I recall a top pitbull breeder talking on inbreeding..ouote "wind em up tight and let em out"

 

[T.Baggins]

I recall a top pitbull breeder talking on inbreeding..ouote "wind em up tight and let em out"

well, look what happened to the old family red blood lines...too inbreed... great, they all look the same.. but their dumb as a bag of rocks and stone cold curs!!
its all about the out crosses.. jeep/redboy.. if you know what i mean...

 

[azad]

well, look what happened to the old family red blood lines...too inbreed... great, they all look the same.. but their dumb as a bag of rocks and stone cold curs!!
its all about the out crosses.. jeep/redboy.. if you know what i mean...

I know what you mean,the old family knew how to breed em right,so did the old timers like hemphill,corvino ect.. Its evident that all types of inbreeding,linebreeding,outcrossing can produce good quality...good dogs, Find em where you can,utilise em as you will!!!

 

[medmaker420]

Love the discussion so far, great writeup gypsy

 

[TexasMonster]

Well, I've been reading these grass growing forums for about a year now. A lot of us newbies (myself included) think we would like to create our own strains. I've been gathering information and thought that I was gaining a handle on grass growing and breeding in general. After reading this thread I now realize I don't know squat except how to get my girls to seed. So, I raise my glass of homemade blueberry wine (16 abv-backsweetened a little) to yall that understand all of this. If yall choose to raise a glass back please wish that I too can someday get a handle on all this. Cheers


It has also come to me that breeders of auto do not have the benefit of keeping some of their older crosses alive like the 12/12 growers do. I wonder what they do to overcome that?

 

[AWoll]

Well, I've been reading these grass growing forums for about a year now. A lot of us newbies (myself included) think we would like to create our own strains.

isnt everything "inbred" to a certain extent? It all had to start somewhere and as populations rise theres no telling what genes are passed as individuals are naturally "selected". I think as far as plants go in a controlled environment if you had the means and resources to do mass selection you could "weed" out undesired traits and characteristics on a multi generational level. How many generations before you can call it your strain? I think thats up to the "Marijuana media" to decide. although if you think about it giving names is almost like naming your kids. i mean who am i to say if someone crosses something with another and names it is wrong in doing so. anyways good read took me forever.
who needs books with this
AWoll

 

[olsmokey]

That was a really informative post.. so its possible to keep back some seed from the first cross and then after inbreeding successive generations to rebreed with the first batch? Instead of clones..but this will be necessarily more variable than from clones, BUT, this variety might actually not be a bad thing. Have I got that right?

Also, they say once you do your first batch you will get 2 distinct phenotypes, then to interbreed each one separately. But surely if you are crossing you wouldn't want to start inbreeding for that would start separating the traits again. I dont get why you would want to separate the phenotypes when you want the best of both phenotypes. ie the smell from one, and the structure from another.

Great thread

Just thought I'd put in my on the subject of inbreeding in nature. Inbreeding is a very important factor in speciation, or the formation of new species. For one, inbreeding can lead to large(ish) restructuring of the genom, wich would with a great degree of certainty not be compatible with 'original' genom. This effect (regardless of degree of inbreeding,) could explain some of the cases of sterility. If these 'sterile' plant were to be bred with genetical siblings, the odds of sucsess would increase with increased genetical similarity.
In many cases, new populations in an area will be started by very few pioneers, this is especially visible on islands. These populations would soon (within x generations) accumulate so many detrimental effects that it might go extinct. Indeed, this has probably happened lots of times, but we only see what is, not what could've been.
But this is where selection comes in. In your garden, you try your best to select genotype based on phenotype, pretty difficult, at best.
Natural selectin, however, selects by more objective criteria. What matters here is relative reproductive sucsess. Let's say there is one genotype (A) that has a one % higher relative sucsess than it's rival genotype (B), and that this advantage is hereditary, than in a relatively few generations A would massively outnumber B.

This scenario is statistical, and does not include accidents or plain bad luck. If A has a nice set of feathers on it's head, while B does not, then this could potentially confer more matings for A. But if some crazy Europeans wants to wear said feathers in their hat, this could make B the sole survivor.
The detrimental effects of inbreeding can be held back by the effects of natural selection. Physical abnormalities almost inevitably lead to lower 'fitness', in effect lower relative rep.sucs. If half your kids get eaten before they reproduce, that's pretty good results in this cruel world. But bad alleles (version of gene) would in a situation of great selective pressure be increasingly rare as their carriers lose the statistical race, or simply gets eaten. Obviously, for the avid gardener, this is not a blueprint. What get selected for in nature is rarely what we want selected for. But nature can show us and we can tweak


To try to summarize, artificial selection upon inbred lines require a great number of 'selectees', and would in a perfect world involve genotype/phenotype-selection, as mimicking natural selection. As this is hardly practical, the phenotype-selection needs to be made according to empirical, objective criterias. There should also be an ever expanding list of reasons to cull. That 50% from one ancestor is well worth remembering.
Inbreeding should not be done to much, and if done, done carefully and documented. Seed strains need the dynamics of a vibrant and varied genepool to stay vibrant. If you can't achieve this, then outcrossing is required. Hybrids are the only way except cloning that combines uniformity and vigour, and the stabilizing of parent strains(PS) should be done carefully. When you find good PS that fulfills your requierements, keeping these as clones is the ONLY way to get the same f1 hybrids more than once. Seed- siblings of your fine parents could also be kept for extended periods, but unless really inbred or selfed, the resulting f1s would not be identical to earlier seeds. This would apply to other generation crosses also. However, difference could vary from none to significant, and breeders can and do get great results this way. But the bottom line for all life is to change or die, and to try to keep a seed strain static, so there will be a point of trade-off between the different thraits selected for, and the problems assosciated with diminishing genepool diversity, vs stability and vigour.

This fast reply of mine after reading the thread became a little messy, due to somebody smoking some good breed, maybe I'll clean it sometime..

Finally, I have an idea I think might be fun to try; When a plant with exceptional potential in breeding/seed production has been identified (with cloning), it is selfed, and following generations selfed etc, untill problems occure. Problems would thus be identified, and compatibility charts could be made for the fine ibl-clones considered for crossing. By thus pressing a clone's selfed line to the edge, one could learn alot about genotype. Then one could try diff crosses and see wich give best results. With good book-keeping this should work out splendidly, but does require space and a somewhat nerdy approach.

I've got heaps of experience in both paticipating in and running field tests of legal crops, even though as of yet none with mj. In my experience, the absolute number one thing is stringent guidelies, and NO slacking on the documentation!! Experimentation without documentation is like putting our willy into the lawn mower. Only dumber

Jeez, I need to learnme self control

Peace, G

 

[Rjstoner]

awesome read gypo!! keep up the good all around work!

 

[Slick 50]

OG Kush is an inbred variety from California. If not grown correctly it will herme extremely bad