Heritability of Intersex Traits

[GreenintheThumb]

Hmmm...I always thought the term X Y was useless if it didn't denote sex. Strange. So there's just two versions of that chromosome and they're termed X and Y regardless if they have anything to do with sex? And a quick google later shows: "In birds, butterflies, and moths, it is the males that have two identical sex chromosomes—they are XX—and females are XY or XO. "

"Generally, proponents of the XY system state that Y chromosome is larger than both the X chromosome
and autosomes, although it is difficult to cytologically discriminate the X from Y chromosome (Yamada,
1943, cited by Sakamoto et al., 2005; Hoffmann, 1961; Peil et al., 2003, Sakamoto et al., 1998). A proof in
this direction could be the higher nuclear DNA content of male C. sativa plants. This is 47 Mbp larger than
that of female plants, possibly owing to the large Y chromosome (Sakamoto et al., 1998). This author found
that the genome size of diploid male plants was 1683 Mbp and of diploid female plants 1636 Mbp. This
difference is not usually detectable by microscopic techniques, but this very exact measurement confirms
earlier observations. "

Thought that was funny. I recall an individual who claimed to be able to see the X versus the Y with a scope. Guess he WAS a liar.

 

[GMT]

it gets worse lol
i think its reptiles though im not entirely sure of that that have rather than X and Y, M and Z, again one is missing a leg.

 

[GreenintheThumb]

THOSE COLD BLOODED BASTARDS!

I guess no one else read the Sex Determinism paper? We gatta keep up class, if we're ganna be ready for the final.

 

[GreenintheThumb]

GMT looks like you and Charles had a lengthy discussion on intersex plants about a year and a half ago. I'm going to pull some quotes.

"Intersex plants are XXY, XYY, or the gene fragment/s that regulates the flowering hormone/s is 'defective', or the mechanisms to neutralize the effect of 'stress' (regular growing conditions) are genetically disrupted. Bear in mind that adaptation is mutation.

Overall, naturally occurring hermaphrodites (in drug cultivars) are not very common. Of course, there are some instances where being intersexed offers a survival advantage (eg jungle environs), but the majority of landrace strains 'breed true' (Note: this is separate from outdoors strains (landrace cultivars) possessing 'sensitivity issues' when cultivated in a less than optimal indoor environment).

As indoor Cannabis cultivation (and to a slightly lesser extent, outdoor cultivation in less than optimal climes) becomes more popular, the incidence of intersex traits will increase. This is largely due to poor genetic selections and poor growing conditions; which when combined, exploits the plants' survival mechanism.

Sincerely,
Charles.



Greetings.

Points of clarification:

Some intersex plants (hermaphrodites) are triploid.

Natural intersex forms are usually diploid. Not always.

Theoretically, 100% triploid is the result of a tetraploid/diploid mating. Triploids can be created from diploid/diploid mating. They are usually infertile, not always (in Cannabis).

Heteromorphic sex chromosomes is believed to be one of the reasons why hormonal suppression occurs. Hormonal suppression also occurs if the gene/s responsible for regulating and/or production of the flowering hormones is defective.

Sincerely,
Charles.


The purpose of the 'Y' chromosome is the same as that of the 'X', to pass on genetic information to the offspring, that result in traits that ensure the plants' survival.

In the wild, survival is often a race against time and other environmental factors. Seeds need to be set before the plant expires. There needs be a hormonal shift in a 'female' plant in order for it to produce pollen; under normal circumstances this shift will not occur if the plant is already pollinated and when this shift does occur, the plant is facing some serious enviromental pressure and responding to it.

What this means is: landrace 'females' (true), will only produce 'male' flowers if other sources of pollen (pollination) are not available. Even though this is an insurance mechanism designed to cope with environmental disaster, it is not successful all the time. Some true 'females' will produce staminate flowers too late in the season, or are too resistant to stress and produce very little amounts of pollen (low staminate flower count), and therefore not enough seeds are produced for a sustainable population. In any case, this is a reason why the 'Y' chromosome exists.

The 'Y' chromosome ensures that lots of pollen is available, early enough in the plants' respective life cycles, to make certain that genetic information from both parents are passed down to the progeny. It then stands to reason that traits like vigour, early and short maturation times, responsiveness to photoperiod, and yield are likely linked to the 'Y' chromosome.

The ability to spread genetic information successfully is important to survival. A plant that produces abundant pollen at the appropriate time has an advantage over others that don't ('male' or 'female'); its genetic material will more likely be passed on. However, adaptation is dependent on maintaining/increasing genetic diversity.

Evolutionarily speaking, having separate sources for genetic information (two parents) is a good thing; and a very good way to ensure diversity is to separate plants that produce copious amounts of pistillate flowers from plants that produce copious amounts of staminate flowers, both physically and preferably genetically.

Sincerely,
Charles."

The man had some interesting thoughts. I wish I could bug him to the point of hating me like I do all the breeders I respect

"A note: As far as sexual inheritance goes, Cannabis closer resembles the crocodilian mechanism, rather than the mammalian one. Under normal circumstances, statistically 50/50, male/female offspring is the result of a standard male/female mating (for exceptions, see below). However, like crocodiles, environmental conditions can and will play a significant role in sex expression. In other words, manipulation of the germinating environment can result in mostly 'male' or 'female' plants.

Furthermore, sometimes in Cannabis there is also a predisposition towards one sex over the other, based on strain or cultivar type. In some landrace populations (notably Thai, Cambodian, Loatian, Central African, Guyanese, Venezuelan) finding true 'female' representatives can prove to be a daunting task. Because these landraces grow in wet dense jungles, where wind pollination is restricted, a preponderance of male and hermaphroditic plants, serves to create the next generation more effectively than the standard 50/50 representation of the sexes. These plants if bred, regardless of changes to their growing (germinating) environment, will produce more males than females (The 'Y' side is more vigorous) . The Thai used to create Northern Lights #5, is an example of this."

I've had quite a few discussions about environmental and epigenetic factors on sexual phenotype. I know Chimera subscribes to the X / Y determinism and discounts environmental effects. I don't understand why the environment is thought to have such a large effect after the genetic markers were found...

 

[elmanito]

Overall, naturally occurring hermaphrodites (in drug cultivars) are not very common. Of course, there are some instances where being intersexed offers a survival advantage (eg jungle environs), but the majority of landrace strains 'breed true' (Note: this is separate from outdoors strains (landrace cultivars) possessing 'sensitivity issues' when cultivated in a less than optimal indoor environment).

Good writing piece from Charles.Never noticed any hermies with the Chinese varieties i grow.I'm curious what will happen when you grow them indoors, if they show any hermie effect of the change of the environment.

The pica in my last post shows that sometimes after 4 generations suddenly some plants can show a hermie effect, while both parents never had any trouble with hermaphroditism.

Even with the human race you have sometimes hermaphroditism.Androgyny is even more difficult to understand for most people.

The only thing what you can do if you wanna know if a plant has both sexes is a DNA check up, although its quite expensive to do.

Namaste

 

[englishrick]

where wind pollination is restricted, a preponderance of male and hermaphroditic plants, serves to create the next generation more effectively than the standard 50/50 representation of the sexes. These plants if bred, regardless of changes to their growing (germinating) environment, will produce more males than females (The 'Y' side is more vigorous) . The Thai used to create Northern Lights #5, is an example of this

I don't understand why the environment is thought to have such a large effect after the genetic markers were found...

Bear in mind that adaptation is mutation.

this is separate from outdoors strains (landrace cultivars) possessing 'sensitivity issues' when cultivated in a less than optimal indoor environment)

As indoor Cannabis cultivation (and to a slightly lesser extent, outdoor cultivation in less than optimal climes) becomes more popular, the incidence of intersex traits will increase. This is largely due to poor genetic selections and poor growing conditions; which when combined, exploits the plants' survival mechanism

Some true 'females' will produce staminate flowers too late in the season, or are too resistant to stress and produce very little amounts of pollen (low staminate flower count), and therefore not enough seeds are produced for a sustainable population. In any case, this is a reason why the 'Y' chromosome exists

Heteromorphic sex chromosomes is believed to be one of the reasons why hormonal suppression occurs. Hormonal suppression also occurs if the gene/s responsible for regulating and/or production of the flowering hormones is defective.

Sincerely,
Charles

amazing quotes...

 

[Jones]

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[GreenintheThumb]

Just read it. Have you by chance read the paper from 1943 that they use as reference for the cannabis sex determination system?

 

[Jones]

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[SIZE=-1][/SIZE]

 

[GreenintheThumb]

I don't know what to say. Seems to be clearly in the stage 3 to me. Certainly, the Y is larger than the X and there's only a small PAR region. This vibes with the earlier abstract you posted, "The recombination analysis led to the conclusion that there is a pseudoautosomal region (PAR) on the sex chromosomes, allowing recombination between the X and the Y chromosome. The other regions of the sex chromosomes show only a few recombination events, for the Y as well as for the X."

 

[Fuel]

And the goal is to remake the definition of the intersex state or to prove all cannabis plants are potentially intersex ? I'm losted in translation.

 

[JWP]

(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

Now that the info has had some weeks to "stew" in my mind i have come back to have a shot at the original questions asked.

"how often is this true female completely homozygous"

i'm not sure anyone out there would be putting time into this but it would be nice to have a baseline reference for sure. You would have to have two, one from pure sativas and one from a pure indicas. Have both the extremes covered.


"Is there any reason at all to expect it to breed true for this trait any more often than say for example yield?"

Yes i would most definitely expect it, especially if a group of homozygous true males and females were used for backcrossing. This would be dominant allele stacking at its most extreme.

I used to have the mindset that all intersex plants should be eliminated but it turns out this was very nieve of me and i realized that other important genes may also be lost in this type of selection.

Its now my firm belief that even pools that are totaly dominated by intersex genes can be worked into "saleable" "stable" lines by using a technique like homozygous allele stacking and it can be done in relatively less time that previously thought.


I hereby declare the terms: "homozygous allele stacking" and "dominant allele stacking" to be the intellectual property of me. Any business or person(s) found to be using this term for proffit will be prosecuted to the full extent of the law.

hahaha my game is definitely at its best at 3:33am each day

 

[Fuel]

I'm not biologist but isn't the "stacking" term a little paradoxal with the homozygous dynamism who is mathematically "suppressor" ?

 

[JWP]

I'm no biologist either, although i do recommend the book "Botany in a Day" to all the budding botanists out there. I'm sure there are tens of you. Or maybe just ten lol.

I'm really just an average guy who likes beer(s) and pot and i have no idea what you just said. Besides its well after my best before time of 3:33am. I'm sorry i wont be much good for answers until tomorrow or later this evening rather.

As you might tell from the tone of my posts that the "stacking" is all a bit of fun. And no i'am not making fun of you, i have the greatest respect for Spain and Spanish people. I do have some spanish genes

"stacking" is just my way of saying "increasing the freequency of the genes on the dominant allele in a given pool" .. hope that answers it for you

 

[GreenintheThumb]

There's already proper terms for everything you describe. Don't be the new rick and start pointlessly confusing other with gobbledygook. So feel free to keep your stacking in the smokers den.

First off, no one knows if there's homozygous true males and females. Secondly, how do you find them? You'd have to progeny test and if the true sex plants weren't dominant (which is very unlikely IMO, if this was true then we'd have less intersex individuals in the pool; after all everyone would only have to find one good mom and cross her to everything before release to eliminate ALL intersexuality in the progeny) how would YOU personally tackle this situation. Third, why would you be backcrossing in your "example", if the plants bred true for true sex then why would you need to be continually breeding back to a single parent? And "homozygous allele stacking" is now a technique? UGH

 

[JWP]

Thanks for your reply GreenintheThumb.

Please correct me if i'm wrong but its my understanding that the whole reason gypsy created this place was so that regular people just like me and rick could come and learn.

I dont feel i'am pointlessly confusing others, rather the opposite. I hope that my words may encourage others to also learn a little more. And i also hope that they are not discouraged from posting their thoughts for fear of copping a grilling from you.

You would have to assume that true homozygous sexes exist. Maybe this would explain why hazes have a significantly higher freequency of female plants. Is it not possible or even likely that some of the females are homozygously true?

Finding them would be a challenge no doubt, but i would do exactly as you said. Breed with only true sexed plants homozygous or heterozygous. If the freequency of true sexed plants increased i would assume that a homozygous true plant were one of the parents.

In my example i said a group of homozygous plants. But that wouldnt be possible untill they were found as you pointed out. You could eliminate one parent at a time from the group of parents untill the progeny revealed a higher ratio of intersexed plants and assume that the eliminated parent was in fact homozygous. Then you would be one progeny test away from confirmation that this plant is homozygously true. Wouldnt that be a leap forward?

You wouldnt have to be backcrossing if they were breeding true. But i would do it anyway. I'am an amature after all. Do you see any problems with me doing this?

 

[GreenintheThumb]

Please correct me if i'm wrong but its my understanding that the whole reason gypsy created this place was so that regular people just like me and rick could come and learn.

Fair enough, but you learn by reading as much by posting IME.

I dont feel i'am pointlessly confusing others, rather the opposite. I hope that my words may encourage others to also learn a little more. And i also hope that they are not discouraged from posting their thoughts for fear of copping a grilling from you.

How are you going to inspire them to learn something when you couldn't be bothered to do it yourself? You may inspire them to start using your gobbledygook terms tho.

You would have to assume that true homozygous sexes exist. Maybe this would explain why hazes have a significantly higher freequency of female plants. Is it not possible or even likely that some of the females are homozygously true?

I have to assume that true homozygous sexes exist? Why do I have to do that? I haven't found a seedlot that I can't get to reverse due to some stress. Do you understand what homozygous true sex means?

In my example i said a group of homozygous plants. But that wouldnt be possible untill they were found as you pointed out. You could eliminate one parent at a time from the group of parents untill the progeny revealed a higher ratio of intersexed plants and assume that the eliminated parent was in fact homozygous. Then you would be one progeny test away from confirmation that this plant is homozygously true. Wouldnt that be a leap forward?

No, that would be a lot of work. A slow stumble forward. Do you understand how much testing this would take, how much time and space all to find a mythical homozygous true breeder.

You wouldnt have to be backcrossing if they were breeding true. But i would do it anyway. I'am an amature after all. Do you see any problems with me doing this?

Yeah there's lots of problems with it but it's very off topic and been discussed to death.

 

[JWP]

I have been bothered but all this isnt something that can be learned over night. It may be some years yet before i can speak and have someone in the know fully understand every word i say.

You cant deny our passion though. We can only convey our ideas with the vocabulary we already have. I think the most important part is that we do speak about these ideas & concepts with the tools we have got.

Of these seedslots some could not be reversed right? Is not not possible that one of these could be homozygous? Why not? Other traits can be homozygous. I do understand what homozygous true sex means and thats why i believe its very important that they are found.

The homozygous true breeder is like the holy grail right. If it ever is found it would be crossed with every variety ever made im sure. It would eclipse all other work that has ever been done before. The one who does find it would be forever immortal in cannabis history. Is that not something worth striving for?

A lot of work or not do you agree that this is a feasible way of finding it, if it does exist? Surely i, one who does not even know the correct terminology for this subject cant have the only idea of how to find them?

How would you find them GreenintheThumb?
Does anyone else have idea about how they can be found?

 

[GreenintheThumb]

I explicitly said every seedlot I've ever evaluated could be reversed by stress.

There are no holy grails, I'm sad to say. And a line/clone/strain only breeds true for what it breeds true for. There isn't a line that breeds true for every trait of interest to drug cultivators and there probably never will be.

About how "they" can be found:

I assume your talking about a homozygous true sex line? I don't think I even understand your methods. You want to do multiple progeny tests from a population while systematically removing the "most true" ladies untill you find the one which will be tested by seeing when the progeny look worse? I guess you could do that but why? It would be faster to individually test all these parents.

As for what I would do to find them. As previously stated, I'm starting to doubt their existence but all my lines would be maintained while conducting strong stress tests and eliminating the largest number of intersex individuals possible as long as it doesn't effect the line's health. As long as the line doesn't have any issues with intersex problems why make that the end all be all part of your breeding program? Oh, to become immortal in the community? I'd rather be forgotten like Vic High and hyb than remembered like Brothers Grimm and BOG.

 

[JWP]

GreenintheThumb, i have learned more from you than you will ever know & i have been inspired to learn even more.

Its clear you know the game very well & are professional about your business. I'm not quite sure who you are or if you have lines released but i would buy your stress tested lines over %99 of the competition out there.

Thanks