Where are we? Ah yeah ok, this is general forum, I can take this on a tangent here. So, how layman? I'll go really simplistic, not to patronise but so anyone reading in the future can also follow.
So in cannabis, sex is determined in two ways, depending on the evolutionary path that the individual lines followed. As in all species' deviations, historically these tended to be geographically separated, such as African and Indian elephants having different ears etc.
In the south eastern area of Asia, you have what is referred to as an X to autosome, sex determining system. In Pakistan India Afghanistan regions, you have the Active Y, system.
Active Y is what we all know and think of in terms of boys and girls. Girls having XX chromosomes as boys having XY chromosomes. So the presence of a Y, determines a male
In X to autosome lines, there is no Y. There are only XX plants. The difference between the generation of female flowers and male flowers, lies in the other chromosomes. This is done by the number of copies of a sex determining gene. I'll give a very basic and simplistic analogy.
If you have two pillow cases with 100 tennis balls in each, and you want to make a third pillow case with 100 tennis balls in by taking half of the balls from each pillow case, you can see this is the same process as breeding two anythings together. Now if each pillow case has mainly yellow tennis balls in it, but one has 8 red ones and the other has 16 red ones inside, we have a difference. If we take tennis balls at random from each pillowcase, then this new pillowcase will be filled with mainly yellow tennis balls, but have a random chance of gaining somewhere between 0 and 24 red tennis balls. The average red count being 12 red balls.
Now in X to autosome systems, there will be a critical number of these genes that will determine if the plant will grow male flowers or not. This gene is referred to as sex-det 1. If the number of copies of this gene is above the critical limit, then these XX girls will grow only male flowers. These will be perceived as boys, however they aren't boys, they are girls with a sufficient sex-det 1count, to express as males. If the sex-det 1 count is below a certain limit, then these XX girls will only express female flowers. However when the sex-det 1 count hovers around this critical limit, you get intersexed flowers being produced.
This is not due to faulty genes as it would be in active Y lines, that can simply be removed from the gene pool, but are a direct result of the system of determination used.
The only way to remove intersexed individuals from such a line, would be to reduce the count of Sex-det 1 genes to 0. This would of course leave the line feminised forever.
Now go back to the pillow cases, by selecting pillow cases with the least red balls in them, and breeding them together, using artificial means, we reduce both the average and the potential range of the number of red tennis balls in the new pillow cases. However if we start breeding a pillow case with red balls below the critical number, (plants that show only female flowers), and pillow cases with lots of red balls (plants that show exclusively male flowers), then we may be increasing the average red ball (sex-det 1) count above the upper limit to show exclusively female flowers, and in turn increase the number of intersexed plants in the offspring.
You will always get the standard deviation curve from the offspring, with plants with low counts of the male flower genes, and plants with the highest count being in limited numbers, at each end of the graph, and with the majority of examples being in-between the two extreme groups averaging out towards the middle, in what is referred to as a standard deviation curve.
This means that by using "males" in x to autosome lines, you are increasing the average count of sex-det 1 genes present in all the offspring. By reversing a female and pollinating either itself or another low count female, you are reducing the average count of sex-det 1 genes.
One way increases the intersexed individuals in the next generation, and the other way reduces it.
Hopefully I pretty much covered that there.
So in cannabis, sex is determined in two ways, depending on the evolutionary path that the individual lines followed. As in all species' deviations, historically these tended to be geographically separated, such as African and Indian elephants having different ears etc.
In the south eastern area of Asia, you have what is referred to as an X to autosome, sex determining system. In Pakistan India Afghanistan regions, you have the Active Y, system.
Active Y is what we all know and think of in terms of boys and girls. Girls having XX chromosomes as boys having XY chromosomes. So the presence of a Y, determines a male
In X to autosome lines, there is no Y. There are only XX plants. The difference between the generation of female flowers and male flowers, lies in the other chromosomes. This is done by the number of copies of a sex determining gene. I'll give a very basic and simplistic analogy.
If you have two pillow cases with 100 tennis balls in each, and you want to make a third pillow case with 100 tennis balls in by taking half of the balls from each pillow case, you can see this is the same process as breeding two anythings together. Now if each pillow case has mainly yellow tennis balls in it, but one has 8 red ones and the other has 16 red ones inside, we have a difference. If we take tennis balls at random from each pillowcase, then this new pillowcase will be filled with mainly yellow tennis balls, but have a random chance of gaining somewhere between 0 and 24 red tennis balls. The average red count being 12 red balls.
Now in X to autosome systems, there will be a critical number of these genes that will determine if the plant will grow male flowers or not. This gene is referred to as sex-det 1. If the number of copies of this gene is above the critical limit, then these XX girls will grow only male flowers. These will be perceived as boys, however they aren't boys, they are girls with a sufficient sex-det 1count, to express as males. If the sex-det 1 count is below a certain limit, then these XX girls will only express female flowers. However when the sex-det 1 count hovers around this critical limit, you get intersexed flowers being produced.
This is not due to faulty genes as it would be in active Y lines, that can simply be removed from the gene pool, but are a direct result of the system of determination used.
The only way to remove intersexed individuals from such a line, would be to reduce the count of Sex-det 1 genes to 0. This would of course leave the line feminised forever.
Now go back to the pillow cases, by selecting pillow cases with the least red balls in them, and breeding them together, using artificial means, we reduce both the average and the potential range of the number of red tennis balls in the new pillow cases. However if we start breeding a pillow case with red balls below the critical number, (plants that show only female flowers), and pillow cases with lots of red balls (plants that show exclusively male flowers), then we may be increasing the average red ball (sex-det 1) count above the upper limit to show exclusively female flowers, and in turn increase the number of intersexed plants in the offspring.
You will always get the standard deviation curve from the offspring, with plants with low counts of the male flower genes, and plants with the highest count being in limited numbers, at each end of the graph, and with the majority of examples being in-between the two extreme groups averaging out towards the middle, in what is referred to as a standard deviation curve.
This means that by using "males" in x to autosome lines, you are increasing the average count of sex-det 1 genes present in all the offspring. By reversing a female and pollinating either itself or another low count female, you are reducing the average count of sex-det 1 genes.
One way increases the intersexed individuals in the next generation, and the other way reduces it.
Hopefully I pretty much covered that there.
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