Hi Zif,
First, a disclaimer: I am not a genetics expert and don't claim to be. I do however have a small amount of knowledge about things that most in our community simply don't understand.
I also have the ability to explain complex things in a way that non-experts can "get it."
When faced with the sweeping generalizations that Hempy has been making, an expert is not required to refute his points.
One must just point out a single case where his statement was not true (which I did with the OG Kush example.)
The foundation of my point is that ALL outcomes in plant breeding are ultimately the result of selection. If/when "inbreeding depression" occurs, it would be the result of the selection choices made by the breeder and not the method of obtaining the pollen.
Selfing accelerates positive progress towards the (inbreeding) goal of isolating traits. That also accelerates other aspects of inbreeding like the appearance of negative traits that exist in the DNA. In the end, (in)breeding is (in)breeding. I probably should have written it that way the first time
I don't like being forced to distill the argument down to that level, but Hempy forces me to because of his ridiculous generalization.
I have no doubt that legal food crops grown at industrial scale for decades, that inbreeding depression is a very real thing.
I get it.
Although in cannabis we have a much broader genepool to work with than what you describe with corn, if breeding were allowed to progress at the the same level as other commercial crops, I am sure examples of inbreeding depression would be easy to find.
As far as Sam seeing depression, I am sure that he saw the negative traits quickly, but I believe the real the question is "did he care?"
The goal of Sam's project that Hempy focused on was basically using a plant to produce a single cannabinoid. He did not have a choice to select away from the high THCV phenos, even though he probably could have easily avoided the "low vigor" traits if he had been willing to.
The high THCV pheno that Sam based his work on was probably not common. I know that he expressed interest in high THCV lines from the community on the forums for many years. He had to be expecting negative traits to be an issue from the beginning, but clearly he already had a plan to deal with them.
Girl Scout Cookies is a good example of a plant where the quality of the smoke has managed to reward growers who continue to grow her regardless of her poor growth performance in the garden (slow growth and low yields) .
There is a qualitative element in selection that sometimes overwhelms the quantitative benefit that can come from more vigorous selections. Those choices are made with intention.
Luckily we have a huge variety of options to choose from with cannabis unlike corn (apparently) and outcrossing expands those options exponentially.
Again, my statement to Hempy was not that a collection of negative traits described as "inbreeding depression" didn't or couldn't occur/exist. Just that the cause of those expressions was not exclusively caused by selfing or even inevitable when using selfing. The cause of those traits aggregating in a pheno is the decisions of which offspring to self to take the line further from F3, F4, F5, etc, or S2, S3, S4 etc.
It is also highly influenced by the heterozygosity of the initial selfed plant or the initial M/F parent selections.
Each of those decisions are more important to the outcome than the pollen production method that led them there.
Breeders may feel like they have no choice but to select for traits that further their initial goal(s), but they do have choices. If they choose to move forward with a selection because of specific desirable traits when they see them combined with undesirable traits, does it make sense to blame the results of their decision on where the pollen came from? Hempy says yes. I say no.
Probably the largest scale example we have of inbreeding in the history of commercial illegal cannabis is the Dutch/EU seed industry from 1984 to the present.
Strains from Nevil, Sam and a few others were knocked off by competing breeders as F2's, F3's, F4's etc for more than 2 decades. Changes in laws and other disasters have resulted in these shops losing parents and having to rework the lines from seed. It is commonly accepted that the loss of breeding stock and resulting re-work has led to a loss of quality on the lines that defined the industry. Somehow though, the inbreeding they have had to do to keep their businesses alive has not resulted in loss of vigor.
Those breeders have made selection decisions that put vigor over the quality of the smoke those flowers produce.
The plants may look the same, but they don't smoke the same.
Anyway, I hope I have explained the thinking behind my statements Zif. Those are great questions and I am glad you posted 'em!
First, a disclaimer: I am not a genetics expert and don't claim to be. I do however have a small amount of knowledge about things that most in our community simply don't understand.
I also have the ability to explain complex things in a way that non-experts can "get it."
When faced with the sweeping generalizations that Hempy has been making, an expert is not required to refute his points.
One must just point out a single case where his statement was not true (which I did with the OG Kush example.)
The foundation of my point is that ALL outcomes in plant breeding are ultimately the result of selection. If/when "inbreeding depression" occurs, it would be the result of the selection choices made by the breeder and not the method of obtaining the pollen.
Selfing accelerates positive progress towards the (inbreeding) goal of isolating traits. That also accelerates other aspects of inbreeding like the appearance of negative traits that exist in the DNA. In the end, (in)breeding is (in)breeding. I probably should have written it that way the first time
I don't like being forced to distill the argument down to that level, but Hempy forces me to because of his ridiculous generalization.
I have not personally inbred a line beyond F4 myself before outcrossing or moving on to other work. In those projects I have never seen anything I would describe as inbreeding depression, although I have completely screwed up lines through bad male selection. Operating under prohibition pressures meant that I was forced to choose single males from small populations and you know immediately the next season when the offspring have gone downhill from the parents.
I have no doubt that legal food crops grown at industrial scale for decades, that inbreeding depression is a very real thing.
I get it.
Although in cannabis we have a much broader genepool to work with than what you describe with corn, if breeding were allowed to progress at the the same level as other commercial crops, I am sure examples of inbreeding depression would be easy to find.
As far as Sam seeing depression, I am sure that he saw the negative traits quickly, but I believe the real the question is "did he care?"
The goal of Sam's project that Hempy focused on was basically using a plant to produce a single cannabinoid. He did not have a choice to select away from the high THCV phenos, even though he probably could have easily avoided the "low vigor" traits if he had been willing to.
The high THCV pheno that Sam based his work on was probably not common. I know that he expressed interest in high THCV lines from the community on the forums for many years. He had to be expecting negative traits to be an issue from the beginning, but clearly he already had a plan to deal with them.
I don't really know anything about corn genetic so I can't contribute or comment intelligently here. I understand your point about the challenge they face with extremely limited genetics to work with. Those must be tough decisions ;-)
Yes. Agreed. Even though the breeder is powerless to affect the how the combination of traits play out, we always have choices to make about which traits are more important to us.
Girl Scout Cookies is a good example of a plant where the quality of the smoke has managed to reward growers who continue to grow her regardless of her poor growth performance in the garden (slow growth and low yields) .
There is a qualitative element in selection that sometimes overwhelms the quantitative benefit that can come from more vigorous selections. Those choices are made with intention.
Luckily we have a huge variety of options to choose from with cannabis unlike corn (apparently) and outcrossing expands those options exponentially.
Agreed. A combination of traits that would be almost impossible to produce if so many of the desirable traits didn't seem to be dominant. Clearly thousands of years of natural selection have had an impact on what we have been left to work with there.
And who knows, maybe someday we'll see that.
Again, my statement to Hempy was not that a collection of negative traits described as "inbreeding depression" didn't or couldn't occur/exist. Just that the cause of those expressions was not exclusively caused by selfing or even inevitable when using selfing. The cause of those traits aggregating in a pheno is the decisions of which offspring to self to take the line further from F3, F4, F5, etc, or S2, S3, S4 etc.
It is also highly influenced by the heterozygosity of the initial selfed plant or the initial M/F parent selections.
Each of those decisions are more important to the outcome than the pollen production method that led them there.
Breeders may feel like they have no choice but to select for traits that further their initial goal(s), but they do have choices. If they choose to move forward with a selection because of specific desirable traits when they see them combined with undesirable traits, does it make sense to blame the results of their decision on where the pollen came from? Hempy says yes. I say no.
No I haven't, and I am not arguing that it's not.
Probably the largest scale example we have of inbreeding in the history of commercial illegal cannabis is the Dutch/EU seed industry from 1984 to the present.
Strains from Nevil, Sam and a few others were knocked off by competing breeders as F2's, F3's, F4's etc for more than 2 decades. Changes in laws and other disasters have resulted in these shops losing parents and having to rework the lines from seed. It is commonly accepted that the loss of breeding stock and resulting re-work has led to a loss of quality on the lines that defined the industry. Somehow though, the inbreeding they have had to do to keep their businesses alive has not resulted in loss of vigor.
Those breeders have made selection decisions that put vigor over the quality of the smoke those flowers produce.
The plants may look the same, but they don't smoke the same.
Anyway, I hope I have explained the thinking behind my statements Zif. Those are great questions and I am glad you posted 'em!
