Heritability of Intersex Traits

[Tom Hill]

(if this beginning seems out of place, it's because it was pulled from another thread to help keep the original thread on topic)

In Central America, farmers come across Mango trees that won't produce. Before they cut them down, they'll beat the hell out of the trunk with a baseball bat while yelling at it, warning the tree what's coming if it doesn't shape up. They'll keep this up for years before cutting the tree down, no shit, pretty funny to watch. I guess I'm wondering how extensive the testing is on these true female phenotypes, infinity seems to be the tests we could run. Until they are complete, I think we should refer to them as "strongly female" - as we do with many other plants. Further, how often is this true female completely homozygous for that which is believed by many to be a very complex trait in the end? Is there any reason at all to expect it to breed true for this trait any more often than say for example yield? -T

 

[GreenintheThumb]

Nothing comes easy Tom but just like yield it makes the most sense to select our "most true" and reject the rest, the same we do for yield and all the other complex traits we covet.

Sam how do you explain the increase in females you found in haze populations?

 

[Tom Hill]

Hi GreenintheThumb,

But plenty comes easy, namely, traits that are under the control of major genes (Mendel). I agree with your Burbank style selection process but many breeders do argue that it makes more sense to postpone selecting for such traits until later generations when the likelihood of homozygous loci is higher.

Sam, my apologies for heading off topic and congratulations on what looks to be a very successful experiment. Are you yet able to categorize the individual in regards to terpene profile etc? -T

 

[GreenintheThumb]

Hi GreenintheThumb,

But plenty comes easy, namely, traits that are under the control of major genes (Mendel). I agree with your Burbank style selection process but many breeders do argue that it makes more sense to postpone selecting for such traits until later generations when the likelihood of homozygous loci is higher.
-T

Hi Tom
Personally I wouldn't put intersex traits on the back burner when it comes to selection. Plenty of other breeders have done that for years and it hasn't worked out well IMO. I'd be much less concerned with yield, flavor, structure and any number of other complex traits in comparison. But what do I know... Frankly, what are we concerned with that is controlled by a few simply inherited Mendel style genes?

 

[Tom Hill]

Hi Tom
Personally I wouldn't put intersex traits on the back burner when it comes to selection. Plenty of other breeders have done that for years and it hasn't worked out well IMO. I'd be much less concerned with yield, flavor, structure and any number of other complex traits in comparison. But what do I know... Frankly, what are we concerned with that is controlled by a few simply inherited Mendel style genes?

Nor would I put it on the back burner I don't think, as stated, I agree with your Burbank style selection process from early generations onward. Just kindof wondering how effective selections away from intersexed traits are, and imagine it's more complex. Sam has agreed to share his findings/progress on this in the past but this is probably not the thread for it. I'm guessing that applying a few stress tests to the breeding candidate surely doesn't mean that all will be well, that was my basic point. For it to be a true female, genetically, should it not have to prove its offspring (obtained by selfing let's say) cannot be reversed via stress either? Otherwise, its breeding value is greatly diminished. It could be that it simply does not reverse via stress due to some modifying autosome/s being masked in heterozygote/s. If that were the case, then it is of no higher breeding value (regarding that trait) than its intersexed sister who gives rise to a lessor percentage of intersexed progeny.

Plenty of breeders have put selections against intersexed traits at the forefront of their programs too, and it hasn't always worked out well for them either, surely.

In my experience, many traits under the control of major genes are strongly correlated to more complex traits, they are individual pieces of this larger polygenetic puzzle. For example, if I select away from various simply inherited structural traits early on (large leaf, petiole, stem, etc) I might see progress towards more complex traits like yield.-T

 

[GreenintheThumb]

Tom
I believe I agree with the main point you were trying to make. I don't, however, see how an intersexed sister of a "true female" would have a less intersexed progeny than the true female herself. I guess I'm not following. Also, you said plenty of breeders are making selections away from intersexed traits; not sure I agree with you here either. Certainly don't on the "plenty" and I have my doubts as to many "breeders" doing simple stress tests, much less progeny testing. This is a great topic tho and it could go further in a lot of directions. I too am not sure this is the best place for it. Not trying to muddle up this thread.

Mods can we copy or move this conversation me and Tom are having into it's own thread. Heritability of Intersex Traits or something along those lines would work. Thanks

 

[imnotcrazy]

I *think* Tom ment:

How can you weigh the value of a female that doesn't show intersexed traits after you round of stress testing if it's offspring do show them..

Also, How can you devalue a female that does show intersexed traits after stress testing, you don't know without crossing this female, and stress testing the progeny, if it may never pass on this intersex trait to it's offspring.

 

[GreenintheThumb]

First off, thanks to the mod who formed this thread. Much appreciation, hit me on pm if you desire some rep. Now lets get into this.

Just kindof wondering how effective selections away from intersexed traits are, and imagine it's more complex.

Not trying to put you on the spot here, but wouldn't you be a better judge of this than most? Have you personally every run into some intersex problems or found a nice strain (i use the term loosely, like most herb enthusiasts) that had a good portion of the offspring with intersex individuals? Do any of your lines ever throw a late banana? Again, really not trying to put you on the spot here, but i don't make seeds so anything i know is from a theoretical standpoint or from the observations of other breeders.

I'm guessing that applying a few stress tests to the breeding candidate surely doesn't mean that all will be well, that was my basic point.

Yeah, no doubt. But at the same time a stress test isn't going to hurt anything and it only takes up a bit more time and space.

For it to be a true female, genetically, should it not have to prove its offspring (obtained by selfing let's say) cannot be reversed via stress either?

That would be great, but couldn't you coin a new term for individuals who's progeny are also true female. Especially if we find that some or most of the true females progeny don't follow the mom. TFP- true female progeny?

Otherwise, its breeding value is greatly diminished.

Hhhmmmm. I understand your point but if you're finding your best females AND doing the stress test even if all the kids aren't TFP you're still making a good selection and pointing the line where you want it to go. Isn't its breeding value only greatly diminished if intersex traits is the only thing under selection?

It could be that it simply does not reverse via stress due to some modifying autosome/s being masked in heterozygote/s. If that were the case, then it is of no higher breeding value (regarding that trait) than its intersexed sister who gives rise to a lessor percentage of intersexed progeny.

I guess I just don't understand why you think her intersexed sister would be better. You mean if there's three different genes or sets of genes that control varying degrees of intersexuality and the intersexed girl only has 1 of the 3? But the "true female" individual has two of the three along with some modifiers that mask those expressions? So while she looks TF in reality she caries many of the genes coding for intersex? Is that what we're imagining? I mean it certainly could be the case IMO. But again, the stress test doesn't hurt anything and the only way to know anything about this is through progeny testing...something that should be happening anyway IMO.

In my experience, many traits under the control of major genes are strongly correlated to more complex traits, they are individual pieces of this larger polygenetic puzzle. For example, if I select away from various simply inherited structural traits early on (large leaf, petiole, stem, etc) I might see progress towards more complex traits like yield.-T

I know what you mean. But don't you think getting a TF may be one piece of the polygenetic puzzle of eliminating intersex individuals from our pool as a whole?

this is a fun discussion, I need to spend more time in the lab with the real cannanerds

 

[GreenintheThumb]

I *think* Tom ment:

How can you weigh the value of a female that doesn't show intersexed traits after you round of stress testing if it's offspring do show them..

Also, How can you devalue a female that does show intersexed traits after stress testing, you don't know without crossing this female, and stress testing the progeny, if it may never pass on this intersex trait to it's offspring.

Yeah, well at the end of the day it all comes down to progeny testing. However, I don't think it's a bad place to start with True Females, the problem that we're all fearing here seems to be that perhaps your TF actually has intersex traits and simply masks them. Something worthy of investigation. But I still believe the best place to start is with the TFs. Who has the time and space to progeny test every hermie? It seems logical that chances are higher that the hermies will have hermie kids and that TFs won't. And even if we find that our TF mom was simply masking her traits we could always select towards that mask and eliminate intersex phenos that way.

 

[shawkmon]

great stuff here, i think there might be something to this intersex female, i used pollen from 1 and grew about 6 plants from the seeds and none have shown nannars,maybe i got lucky, keep the info coming, peace

 

[Tom Hill]

Tom
I believe I agree with the main point you were trying to make. I don't, however, see how an intersexed sister of a "true female" would have a less intersexed progeny than the true female herself. I guess I'm not following. Also, you said plenty of breeders are making selections away from intersexed traits; not sure I agree with you here either. Certainly don't on the "plenty" and I have my doubts as to many "breeders" doing simple stress tests, much less progeny testing. This is a great topic tho and it could go further in a lot of directions. I too am not sure this is the best place for it. Not trying to muddle up this thread.

Mods can we copy or move this conversation me and Tom are having into it's own thread. Heritability of Intersex Traits or something along those lines would work. Thanks

Hi again,

It is possible for an intersexed sister of a "true female" to give rise to less intersexed progeny because the term "true female" as it is being used (and requoted often) is nothing more than a phenotypic expression. It's like somebody saying that they have a "true" large yielding phenotype, they have tested it in 20 different environments and it yields huge no matter what. Yeah, well, self it, and get back to me is my first thought. These are complexly inherited polygenetic traits and that environment can have an affect on them also places them squarely under the heading of quantitative characters. And though phenotypic expression is certainly correlated to genotype over the long term, experience has shown over and over again (not just my experience, the entire history of plant breeding) that we must be very careful in placing too high of an importance on the parental phenotype, especially when we are discussing these type of traits. -Tom

I guess I just don't understand why you think her intersexed sister would be better. You mean if there's three different genes or sets of genes that control varying degrees of intersexuality and the intersexed girl only has 1 of the 3? But the "true female" individual has two of the three along with some modifiers that mask those expressions? So while she looks TF in reality she caries many of the genes coding for intersex? Is that what we're imagining? I mean it certainly could be the case IMO. But again, the stress test doesn't hurt anything and the only way to know anything about this is through progeny testing...something that should be happening anyway IMO.

Basically yes.

Have you personally every run into some intersex problems or found a nice strain (i use the term loosely, like most herb enthusiasts) that had a good portion of the offspring with intersex individuals? Do any of your lines ever throw a late banana?

To the first question, yes, and ironically the seeds were obtained from a very knowledgeable breeder who has been selecting against intersexed traits for decades. To the second also yes, but never in decades have I had any measurable amount of a crop (from my stock) ruined due to intersexed individuals.

I know what you mean. But don't you think getting a TF may be one piece of the polygenetic puzzle of eliminating intersex individuals from our pool as a whole?

Naw, not really, I think folks have their tin foil hats on and they need to get with the fact that drug strain cannabis is subdioecious, and that this is not quite the problem they sometimes make it out to be. I wonder, where does all this seeded grass go due to this plague, 99% of it must basically disappear? No, it just doesn't represent the problem folks try to make it out to be imo, we're all smoking seedless. If true females are one in a thousand, how many are also any good on top of that? The number must be so insignificant that I wouldn't hold my breath waiting for them to have much effect on the genepool. And being that we are only talking about phenotypic expression, it really doesn't matter a whole lot anyway, imo-T

Yeah, no doubt. But at the same time a stress test isn't going to hurt anything and it only takes up a bit more time and space.

I think it may hurt the genepool in the long run. I am currently selecting away from intersexed expression under stress. But I kind of feel that this selection is an unnecessary bottle necking and so am also maintaining stock that has not has this type of selection done to it. I surely wouldn't apply the type of stress that would leave us only with what some might call true females, that would be an irresponsible massacre of genetic material imo, and just maybe, all for not whatsoever. -Tom

 

[Mr. Stinky]

hate to jump in the middle, but does anyone think there is actual TF plants out there? not just phenotypically TF, but genotypically? its such an ingrained trait in MJ, actually in so many plants, it seems analogous to you trying to breed out the "green" gene. and so it seems to me to be a waste of time when there are many worthwhile traits we can be selecting for.

and what if you did get a TF strain? then what? you cannot cross it with anything. not without huge amounts of work getting back to TF as well as pulling out the other desirable traits.

just thought id add my instead of just tagging the thread with a random post like every other moron here

 

[GreenintheThumb]

It is possible for an intersexed sister of a "true female" to give rise to less intersexed progeny because the term "true female" as it is being used (and requoted often) is nothing more than a phenotypic expression. It's like somebody saying that they have a "true" large yielding phenotype, they have tested it in 20 different environments and it yields huge no matter what. Yeah, well, self it, and get back to me is my first thought. These are complexly inherited polygenetic traits and that environment can change them also places them squarely under the heading of quantitative characters. And though phenotypic expression is certainly correlated to genotype over the long term, experience has shown over and over again that we must be very careful in placing too high of an importance on the parental phenotype, especially when we are discussing these type of traits. -Tom

Okay, but pretty much everything we're interested in is a complex polygenetic trait. So while this all does apply to intersex stuff, it also applies to most of the things I find interesting about this plant we all love. But just like you keep and further test individuals that show high yielding phenotypes over a large range of environments shouldn't you select individuals with the least incidence of intersexuality?

Naw, not really, I think folks have their tin foil hats on and they need to get with the fact that drug strain cannabis is subdioecious, and that this is not quite the problem they sometimes make it out to be. I wonder, where does all this seeded grass go due to this plague, 99% of it must basically disappear? No, it just doesn't represent the problem folks try to make it out to be imo, we're all smoking seedless. If true females are one in a thousand, how many are also any good on top of that? The number must be so insignificant that I wouldn't hold my breath waiting for them to have much effect on the genepool. And being that we are only talking about phenotypic expression, it really doesn't matter a whole lot anyway, imo-T

Well some of my clone moms show intersex traits and I find it annoying. If I were a breeder, I'm sure it would be a much bigger problem. I don't follow you on the phenotypic expression comment. So if your stuff doesn't hermie in your grow but when people grow out your work they have problems, that just isn't of concern to you?

I think it may hurt the genepool in the long run. I am currently selecting away from intersexed expression under stress. But I kind of feel that this selection is an unnecessary bottle necking and so am also maintaining stock that has not has this type of selection done to it. I surely wouldn't apply the type of stress that would leave us only with what some might call true females, that would be an irresponsible massacre of genetic material imo, and just maybe, all for not whatsoever. -Tom

Well, I don't think anyone's suggesting to purposefully ruin your garden in pursuit of the magical "true female" that will save us all but doesn't it make sense to test your moms at some point? You could fit a bunch of them in just one lil tent and fuck with the light cycle and pH. Don't see how this hurts. I really don't understand at all why you're so fearful of selection against intersex plants. But I do understand why you'd save your germplasm and not put all your eggs in one basket. As mentioned many of the traits we're interested in are most likely as genetically complex as the intersex problem. Do you also have hesitation when selecting for flavor, potency, yield or anything else?

 

[Tom Hill]

Okay, but pretty much everything we're interested in is a complex polygenetic trait. So while this all does apply to intersex stuff, it also applies to most of the things I find interesting about this plant we all love. But just like you keep and further test individuals that show high yielding phenotypes over a large range of environments shouldn't you select individuals with the least incidence of intersexuality?

We want it all GreenintheThumb, but ultimately it is a compromise, this is reality.

Well some of my clone moms show intersex traits and I find it annoying. If I were a breeder, I'm sure it would be a much bigger problem. I don't follow you on the phenotypic expression comment. So if your stuff doesn't hermie in your grow but when people grow out your work they have problems, that just isn't of concern to you?

Yes, it does concern me, greatly, I have to answer for my product and I take that with the utmost seriousness. This is why I am subjecting plants to stress testing currently and selecting away from intersexed traits that I may be able to force to the surface. It also concerns me that it may be foolish for man to breed cannabis to prepare for such conditions, it worries me what genetic material we are throwing away along with it - you see, I also have to answer to our grandsons for what I have done so to speak. So I will also maintain stock for my personal holding that has not been subjected to such selections. In my opinion, increased intersexed expression is not even worth mentioning when we speak of the genetic erosion of cannabis that has taken place in the last few decades. My comment about phenotypic expression is the same I've been saying all along. Just because we go through the trouble of finding a "true female" doesn't necessarily translate to making any forward progress at all towards the stated goal of eliminating intersexed traits from a genepool.

Well, I don't think anyone's suggesting to purposefully ruin your garden in pursuit of the magical "true female" that will save us all but doesn't it make sense to test your moms at some point? You could fit a bunch of them in just one lil tent and fuck with the light cycle and pH. Don't see how this hurts. I really don't understand at all why you're so fearful of selection against intersex plants. But I do understand why you'd save your germplasm and not put all your eggs in one basket. As mentioned many of the traits we're interested in are most likely as genetically complex as the intersex problem. Do you also have hesitation when selecting for flavor, potency, yield or anything else?

I am not fearful of selecting against intersexed traits under natural environmental conditions, that is an automatic. But I am realistic too. I know that if I subject plants to excessive stress and eliminate many, over time, I will have limited my potential progress towards other traits that are much more important imo. -T

 

[GreenintheThumb]

Okay, thanks for the info. I do see what you mean. Perhaps sometimes we all want to reach for the stars when we can't even make it to the door. This genepool of ours should be of great concern to all of us, growers and breeders alike.

You mentioned you're stress testing some stuff as we speak. Can you expand upon this, how have you stressed them. pH, light, nutes? I'm curious. Also are you testing your preselected parents or have you just decided to treat the whole population as you're making selections? Thanks for your input Tom.

 

[Tom Hill]

Hi again GitT,

Yes, it is our nature to reach for stars, that's good. It is also good that we are likely reaching for different stars. Where each of us individually compromises is what separates us, and our cannabis.

Regarding stress testing, mostly light stress, this seems to be the most effective test to force intersexed traits ime. To start with the plants are only recieving 15 watts of light per sqft throughout these grows. Well, not really, the ones directly under the light receive more, the ones further away, less, but that is the average spread. Then these tents leak light like a sieve, I have not measured it, but it is measurable for sure. During the dark period, I can very easily see my hand held out in front of my face at arms length.

I am removing plants from the population that waiver sexually under these conditions. Then as I build the library of selected clones - candidates for further breeding, they are further and with more pressure tested as a part of overall evaluation. I can say with certainty though that if a favorite ever receives low marks at some point of phenotypic evaluation, I move on to genotypic evaluation with it -always- before making any rash decisions.-T

 

[GreenintheThumb]

I see. Thanks again for sharing. Trust me, growers love hearing what's going on "behind the scenes." So is this stress trial something you just started trying recently or have you been doing this for years? And I guess at least this time you're subjecting all your new selections to this treatment, you're not just putting your older moms through this treatment?

Seems like a good plan to me, I wouldn't be throwing out something I consider special for having intersex traits in that environment without evaluating progeny as well.

How many intersex individuals do you find per 100 in the average population or is it increadibly line dependent?

Again, thanks for sharing I love hearing about this sort of thing.

 

[kopite]

It is possible for an intersexed sister of a "true female" to give rise to less intersexed progeny because the term "true female" as it is being used (and requoted often) is nothing more than a phenotypic expression. It's like somebody saying that they have a "true" large yielding phenotype, they have tested it in 20 different environments and it yields huge no matter what. Yeah, well, self it, and get back to me is my first thought. These are complexly inherited polygenetic traits and that environment can have an affect on them also places them squarely under the heading of quantitative characters. And though phenotypic expression is certainly correlated to genotype over the long term, experience has shown over and over again (not just my experience, the entire history of plant breeding) that we must be very careful in placing too high of an importance on the parental phenotype, especially when we are discussing these type of traits. -Tom

IMO most people just go on phenotypic expression - a lot never even test the chosen pheno in any other enviroment or look at the progeny - the selection is already done in their eyes.

Kopite

 

[Tom Hill]

Only recently have I been imposing this added selection parameter, as I said, I've observed no problematic intersexed expression in the past and saw no reason for it. All the latest selections are being subjected to this. However, I expect to see no measurable short-term improvement with this added light-stress parameter, I have the feeling that it is relatively superfluous over the short term. The reason being as stated before is that throughout the history of plant breeding (as well as my own observations) the correlation between phenotypic value and genotypic value tends to be quite low. Mass selection, where individual plants are selected or rejected based on phenotypic value, has proven to be a very slow and inefficient breeding scheme regarding short-term progress.

The percentages of plants with intersexed traits observed under stress is very much line dependent, large differences among lines. In my experience, the background genotype of the population is much more influential than the phenotype of the individual parent in regards to these types of traits. IE, just because you find a "true female" in a population of Thai genetics with a history of intersexed traits, don't expect quick progress towards ridding the population of that trait by using it as a parent.

PS- Hi Kopite. -T

 

[Fuel]

funny

funny

Put a female or a male in "stress" (i hate this term when it's used with vegetal reign...) reveal if some specimens in the line turn herm' under bad conditions, for don't consider them as pure when they aren't.

So, for me it's more a second filter for a minority of plants (who are selected only, i find than grow all the line under these conditions is just a waste of time on the planning) than a true manner to master the intersex trait, wich is not as easy to drive than the potency or yield. Because it's both a suppressor trait (chem' fem' seeds are a good example for that with males) and a dominant trait.

Now, for a "one shot" breeding project it's impossible to see any results behind the heterosis in only one generation. The herm drift can happend in F3 or F4 in some lines, where the herms are totally out in F1 and in F2. It's an example for show than selected phenotypes don't necessary represent well a genotype in short projects.

For the yield i prefer give a good condition of grow and particulary watch the roots mass for reach the high score of my lines. And it's not rare than in selection the most vigorous and generous phenotypes are latent hermaphrodites.

I mean than for long time projects (IBl's etc..) it's necessary to put some checkpoints on it, wich it's not necessary true for projects based on the heterosis quality of the results.

have all the best