Males are they even needed?

[GMT]

Harry, white folk are descended from a family of only 27 individuals, and now there's millions. We're doing OK. Whether meiosis or some other mechanism takes care of it is unclear, I guess selection is key.

Hooka, now you reworded your objection, I finally get what you are saying. As I said, I assumed there would be some process to prevent it, but when both Sam and Chimera claim to have done it, I have to take their word on it and assume there isn't in cannabis. I'm not prepared to say they both lied about it.
Therefore I simply do the maths. Namely if an xx can lose an x and gain a y, to become an xy, an xy can lose an x and gain a y to become a yy.

I'm done on this, I'll leave either Sam or chimera to come in and defend the claims that they have done what they say they have done. I wasn't there, they were.

https://www.icmag.com/ic/showpost.php?p=7521635&postcount=397

https://www.icmag.com/ic/showpost.php?p=7149435&postcount=365


Hmmm, some of the posts I read no longer seem to be there.

 

[GMT]

I have learned a valuable lesson here, post the quotes before posting the post. Don't believe everything you read as it may not be there the next time you go to read it.

 

[knucklehead bob]

Harry, white folk are descended from a family of only 27 individuals, and now there's millions. We're doing OK. Whether meiosis or some other mechanism takes care of it is unclear, I guess selection is key.

Hooka, now you reworded your objection, I finally get what you are saying. As I said, I assumed there would be some process to prevent it, but when both Sam and Chimera claim to have done it, I have to take their word on it and assume there isn't in cannabis. I'm not prepared to say they both lied about it.
Therefore I simply do the maths. Namely if an xx can lose an x and gain a y, to become an xy, an xy can lose an x and gain a y to become a yy.

I'm done on this, I'll leave either Sam or chimera to come in and defend the claims that they have done what they say they have done. I wasn't there, they were.

https://www.icmag.com/ic/showpost.php?p=7521635&postcount=397

https://www.icmag.com/ic/showpost.php?p=7149435&postcount=365


Hmmm, some of the posts I read no longer seem to be there.

I have learned a valuable lesson here, post the quotes before posting the post. Don't believe everything you read as it may not be there the next time you go to read it.

Maybe because what they are talking about is a thing that is hoped or wished for but in fact is illusory or impossible to achieve ?

 

[Hookahhead]

Therefore I simply do the maths. Namely if an xx can lose an x and gain a y, to become an xy, an xy can lose an x and gain a y to become a yy.

I’m not sure what you mean here? In a reversal, nobody is gaining or loosing chromosomes. We’re simply interfering with the mechanism that differentiates flower expression.

It would seem (and makes sense to me), that an X chromosome can produce a female or male flower. While a Y chromosome can only produce male flowers, which is why I think total reversal on a male might be impossible. His X chromosomes can be forced to produce ovules, but those pesky Y’s never switch.

Just to recap for anyone still confused

Normal reproduction:
XX (female) x XY (male)

The seed plant (female) can make ovules from either X, which can be fertilized by either X or Y donated from the male. Giving us 50:50 female to male in the population.. although genetically they’re different... 25% of each X1X, X1Y, X2X, X2Y

Feminized reproduction:
XX (female) x XX (reversed female)

The seed plant (female) can make ovules from either X, which can be fertilized by either X donated from the reversed female. Giving us 100:0 female to male in the population.. although genetically they’re different... 25% of each X1X3, X1X4, X2X3, X2X4

Reversed male
XY (reversed male) x XY (normal male)

The seed plant (reversed male) can make ovules from only the X, which can be fertilized by either X or Y donated from the normal male. Giving us 50:50 female to male in the population.. although genetically they’re different... 50% of each X1X, X1Y.

This last scenario is VERY interesting and something that I had overlooked until writing it out. A reversed male used as a seed plant, will ONLY pass on its X chromosome. Therefore I think this could be valuable tool in breeding if the goal is to stabilize the line, since you’ve removing 50% of the possible variation in each generation.

Edit: I thought of one other scenario..

Double rainbow reversal
XY (reversed male) x XX (reversed female)

The seed plant (reversed male) can make ovules from only the X, which can be fertilized by either X donated from the reversed female. Giving us 100:0 female to male in the population.. although genetically they’re different... 50% of each X1X2, X1X3

In this scenario we’re eliminating 50% of the diversity and creating an all feminized line!

 

[bsgospel]

https://sci-hub.tw/10.1007/s10681-016-1641-2

Identification of QTLs for sex expression in dioecious and monoecious hemp

Sam and others pointed out, and this paper seems to confirm, there is no other linkage than sexual organs. If the male is not necessary for fitness then it can be replaced. Recombinant types may have adaptive value but we are not going to be alive long enough to see those kinds of changes play out.

This also references the Charlesworth paper Kief posted a page or two back.

"The identification of QTLs for the quantitative variation of sex expression on the sex chromosomes of hemp and the recombination rates observed between the sex chromosomes contrasted with the situation in Silene latifolia, a well-studied dioecious species with heteromorphic sex chromosomes (Filatov et al. 2001). In S. latifolia, recombination is absent from most of the Y chromosome (Charlesworth 2002), while the genetic basis of sex determination is strong, and there is little evidence for lability or environmental effects (Ainsworth 2000). According to Charlesworth et al.
(2005), the suppression of recombination between the sex chromosomes in dioecious species results from the presence of sex-determining genes and the evolution of Y-linked genes that benefit male but not female functions, both effects resulting in selection against recombinants. In hemp, it is possible that the recombination rates observed between the sex chromosomes allow the exchange of genetic factors that affect the production of flowers of a given sex. Compared with Silene, in hemp, the individuals with recombined sex chromosomes would have a relatively high adaptive value, as supported by the diversity of intersexual forms existing in the species."

 

[GMT]

Really hooka? Come on, I conceded your new argument , (it may have been your original argument, its hard to tell at this point) has merit. Now you want to stick the knife in?
Perhaps I should have said begets rather than becomes, but when reducing formulas in maths, the language is usually becomes. From what was written though, you should have been able tell what was being said. The argument being refuted originally was, and I have learned my lesson here

Again your under the assumption that the seed parent is passing down a Y chromosome. That’s not how an xy mating system works.

The seed parent is able to pass down a y or there would be no ys in the offspring.

The mother is normally xx and a male offspring is xy. Therefore mother loses an x and offspring gains a y.

Off the back of the premise that what I had read in another thread, links to the thread have been posted, though I cannot now find the relevant posts within that thread, were true, my logic was sound. My premise may not have been. Was that if that process can happen in that situation, it can also happen when a male is reversed and used as a mother.
Hence an xy "mother" could give (and I'll pick my words) rise to yy offspring, when those offspring were "fathered" by a male.

Taking a quote out of context and applying a new meaning is a low blow man. I accept that I accepted the premise on face value, and perhaps I shouldn't have, but as I said, I have conceded that point already.
I didn't accept the paper quoted on face value because it wasn't talking about cannabis.

Do you really need to build me a cross?

 

[Hookahhead]

I’m sorry I wasn’t trying to nitpick, I honestly wasn’t sure what you meant after reading it a few times. The rest of the post was mostly me writing it out for my own reference later on. Again no disrespect buddy, I’m not trying to attack you sorry if it came across that way. Cheeers!

The paper bsgospel posted seems to suggest that we can’t equate Kiefs paper to cannabis, so that post is likely irrelevant. This is definitely outside of my field of study.

 

[bsgospel]

(When in doubt, Sam's building a library. Any thing you need....)

 

[GMT]

Man this is outside of almost everyone's field. Certainly mine. I can only rely on logic here rather than experience. I may have over reacted above, I just felt you were being intentionally condescending and since that was not the case, I will too apologise. Now we have the sickly sweet Disney ending, we'll have to wait on word from someone who's wheel house this is in to give us the definitive answer.

 

[vanilla dutch]

And when it comes to males does it matter what pollen sac on a specific branch ,or are all the pollen the same on a plant?

 

[Hammerhead]

The pollen from these will carry those bad traits. If used it will pass on those traits. So Pollen from a sac found on a female shouldn't be used IMO. If your referring to all male plants it wont matter where you collect the pollen its all the same.

 

[hellfire]

What are traits that seem to be male only? What genes would males carry that females do not?

The genes for pollen sac and size? Seemingly not...these are also expressed from females when they get reversed. Specific reproductive genes that would be in males alone? The male flavor side - ? - letting a male go through flower will show you a more in depth look at his traits, smells, colors etc.

What about something like the gene that passes on sterility? I have had a sterile male in the past but never a sterile female. The virgin goldmine sensi...

Curious if nspecta is around I think he has made a few male x male seeds. I imagine Sam and Chimera probably have had the chance to make and start some males x males.

As for a pure objective goal of preservation of any line, keep the males till we know better.

 

[troutman]

I think MonSamTo wants seeds that are sterile so nobody can breed naturally anymore.

It's probably a patent thing as well.

 

[ctg]

One of the largest problems in cannabis breeding over the last 30 years has been using one male to one fem or even now days one fem to one fem to produce seed stock. Every time this is done the genetic pool within the population gets smaller and smaller. Take for instance c99, when it first came out it was killer, super tasty, quick flowering and potent. Each generation after that the plants got more and more boring. Over several generations the cultivar lost many of its desirable characteristics. This is only one example, roadkill sk and many other cultivars have been lost by this train of thought in the cannabis industry.

I have used multiple males for many years, Vic high actually turned me onto using multiple males to ensure diversity within my seed lots and it’s worked fairly well over the years and has shown me some extremely nice plants within various cannabis cultivars I’ve bred and grown.

So in short yes we do need males within cannabis populations, they are an extremely valuable tool when breeding but as I said folks shouldn’t be using a one on one breeding approach, whether using males or fems for the pollen donors
Mankind has a propensity for destroying the natural cycles in nature!
-ct-

 

[vanilla dutch]

Or to speed up breeding easy to guess what ur females will end up as

 

[Hookahhead]

@ctg, I’m curious about using multiple males. When you’re going to make a given cross, do you select males that are similar or dissimilar? Do you collect pollen and mix it before application? Selecting similar males would still put you towards your goal without sacrificing as much diversity.

I would like to point out you could still do the same thing with an all feminized line, just with multiple reversed females. Properly made feminized seed will carry the same amount of genetic diversity as a regular seed line.

Everyone likes to talk about maintaining diversity in cannabis. Variety is the spice of life and it’s important to maintain it. However the truth is there is also a lot of shitty weed out there, and slowly removing these from the population will benefit the cultivated crop overall. The danger is that we really have no idea which traits may or may not be beneficial because we’re constantly learning new things about this and other plants.

If you look at seed sales, feminized and autoflower are the top sellers. Both of these get a lot of flack from the community, yet their sales are still growing. It’s easy to see why... our population runs on convenience. They eliminate some of the steps you need to learn in order to successfully grow the plant, yet you can still successfully produce some high quality flower from these seeds. Even “master” growers are starting to change their tune.

So here’s where the two factions collide. We can see the incredible diversity this plant has to offer, and the importance in saving it. Yet all of us want to grow the best weed possible, though we may have different criteria we use to judge. No dispensary or major black market player is going to pick up 4-8% THC flower no matter how rare the seed line is. Preservation and progress are both equally important goals.

However it’s all kind of a moot point when genes for certain synthases can be knocked out relatively cheap and reliably in a lab.

 

[therevverend]

One of the largest problems in cannabis breeding over the last 30 years has been using one male to one fem

I think that's how breeding works, I don't think it's possible to use multiple males to create a seed. Or somehow combine multiple females into one seed, unless you can reverse them and shove all the genes into another pistil.

Even if I'm using multiple males on the same female, which I sometimes do, I always keep the pollen separate and labeled. Otherwise you have no idea which traits were passed from what. Over the years very few breeders keep notes, use labels, knowingly cross a select male with a select female. Mostly stuff is unlabeled, mislabeled, forgotten, crossed by God knows what. I don't think people realize how fucked breeding was, in the 1990s, for instance. All sorts of great shit ended up culled.

Even in nature there are powerful selective pressures at work and very few plants are able to successfully reproduce for the next year. All the outliers, too early, too late, too in the middle, got ate by birds, got ate by a deer, certain traits come to dominate. Same with landraces, except with people selecting depending on what they consider useful or legal at the moment, there's even more selective pressure.

For instance you want to preserve a landrace so you plant 100 seeds and ensure they all sprout. Then you grow them all and let them all fuck each other for ten generations. You'll end up with something likely quite different from the landrace you started with.

Just allowing all 100 seeds to sprout instead of letting the regional conditions determine which 100 will start to flip things. The process will continue at each stage of life until a completely different selection process has taken place. This is why 'landrace preservation' has been such a failure in the cannabis world. You see it all the time in the sativa thread. A guy swears this is 'Thai Stick 1976' and everyone complains because it has wide leaves. He may have kept it genetically pure, outcrossed, done everything 'right'. It will still evolve, just like the world does.

 

[vanilla dutch]

I'm sure the first pollen grain? To hit a pistil is what pollinates.quite sure

 

[Hookahhead]

I'm sure the first pollen grain? To hit a pistil is what pollinates.quite sure

Again not a personal attack on anyone, but I’ve been told only a fool is ever sure of anything...

In pollination, hundreds of sperm-carrying pollen grains stick to the stigma suspended in the middle of a flower and quickly grow a tube down a long shaft called a style toward clusters of ovules, which hold two female sex cells. This could be a chaotic frenzy, but for the plant to succeed, exactly two fertile sperm should reach the two cells in each ovule — no more, no less. No ovule should be left out, either because too many tubes have gone elsewhere, or because the delivered sperm don’t work.

In the journal Current Biology, Brown University biologists report that flowers have evolved an elegant safeguard system to ensure that only the minimum necessary number of pollen tubes will reach each ovule.
“There is a mechanism that prevents too many pollen tubes from delivering too many sperm,” said Mark Johnson, associate professor of biology at Brown and senior author on a new paper detailing the discovery. “But the other cool thing is that there is also a way to salvage fertilization if the first father is a dud.”

Essentially the successful fusion of sperm and female gametes immediately terminates the signaling that attracts pollen tubes to the ovule, a finding by first author Kristin Beale, a graduate student in Johnson’s lab.

“Previous models had said that pollen tube entry was sufficient — that once one pollen tube entered, others would be repelled,” Beale said. “But we show it’s the process of gamete fusion.”

Added Johnson: “Until fusion has happened, there’s no guarantee that you’ll have successful seed formation.”

A mystery solved with mutants

Although scientists have studied plant reproduction for centuries, the tools to make Beale’s finding have only become available in the last few years, Johnson said. Armed with these new capabilities, the team, including second author Alexander Leydon, conducted a series of experiments in Arabidopsis plants, a model plant for research.

The most important tool was a pollen mutant the team had discovered called hap2. The mutant grows a pollen tube to an ovule and bursts to release sperm, a normal course of events. But hap2’s sperm can’t fuse with the female gametes. It is a convenient dud. The team also employed new techniques that allow pollen tubes and the sperm they carry to fluoresce as green or red. That way they could watch as different tubes interacted with the ovules.

In their first experiment, the team sent in healthy sperm, half of which were carried by red-tagged tubes and half of which by green-tagged tubes. With nothing but healthy sperm in the mix, only about 1 percent of ovules ended up with multiple pollen tubes (a phenomenon that Beale calls “polytubey”). Ovules could block polytubey in the vast majority of cases.

Then the team unleashed a sampling of sperm in which one in four were duds. Polytubey increased tenfold. One unfortunate ovule ended up attracting four tubes, indicating polytubey is allowed until a fertile sperm comes along.

In another experiment with mutant sperm tagged red and normal, or “wild-type” pollen tubes tagged green, the researchers saw polytubey only where there was a red glow under the microscope.

“We did not observe ovules that were targeted by two pollen tubes carrying wild-type sperm,” they wrote in the journal. “Ovules first targeted by defective sperm can attract additional pollen tubes; but when wild-type sperm are attracted, subsequent pollen tubes are blocked.”

In the paper the team also showed that one of two cells responsible for attracting pollen tubes will persist in the ovule until gamete fusion occurs. While the team didn’t identify the exact signaling molecule responsible for blocking polytubey after gamete fusion, Johnson said, the study does help scientists determine what that signaling molecule must be like. He said it must be fast-acting and potent.

Johnson said the research may eventually have applications in agriculture, either because it could aid fertilization when it is hindered, for instance by bad environmental conditions, or commercial corn breeding. Seed companies create hybrids by fertilizing corn with hand-collected pollen, and to do this they need varieties where male fertility can be controlled.

Nature’s own system, however, appears to guarantee that virtually every ovule will have exactly the right amount of healthy sperm. By employing this newly understood mechanism, flowers thereby become the most prolific moms they can be.

https://news.brown.edu/articles/2012/05/flowers

Sorry for the long ass quote, but I thought it was a good read and relevant to this topic.

 

[GMT]

I'm not sure that the above quote shows any one seed has multiple fathers, just that the mother is a bit of a whore. Where many are invited to try, unless I'm reading it wrong, ( possible) it still seems to suggest that once fertilised, further attempts are blocked. That seems to assume each seed has one mother and one father, even in an orgy.