THCPezDispenser
Makka Pakka Smoka Doob
- Joined
- Sep 9, 2007
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The concept of feminized seeds fascinates me, as well as having many practical applications to be able to create them yourself. I personally am very sporatic as to when I can have a grow going, so having the ability to start a small grow whenever I want without having to plant seeds and sex multiple plants or without having to maintain a clone mother and yet still be self sufficent appeals to me.
Below is my mental consolidation of the information I have uncovered in regards to making feminized seeds correctly, and hopefully this outlines how the members here can try making them for themselves. To be clear, I am in the process of doing this, and the article I have put together below is not based on experience but rather research. A peer review from the group will hopefully find any flaws in my logic or statements I have made, but I feel the article I have put together is based on generally accepted principles. You be the judge
Background – Marijuana Reproduction
First, some background. Marijuana is what is known as a gonochorist reproducer, meaning it has two distinct sexes of individuals (both male and female), similar to humans. This is uncommon in the plant world, where most flowering organisms are predominately hermaphrodite, having both male and female reproductive structures on the same plant. A look at a typical daylily clearly illustrates this as the female pistil is surrounded by male pollen producing stamen.
In the world of marijuana cultivation hermaphrodites do exist. While not the natural state of the plant, a hermaphrodite (or “hermie” as they are colloquially known), is a marijuana plant that produces both male & female flowers. This is a very undesirable characteristic in the context of growing marijuana for the harvesting of THC as a hermie can ruin an entire crop of what would have been sensimilla female buds due to pollen distribution in the growing environment. The pollen will fertilize any female flowers that it lands on, thus dramatically reducing the THC contents of the bud as the female plant redirects its energy from producing sticky THC to catch pollen to seed production, which have no appreciable THC content.
The hermie genetic trait is thought to be a survival characteristic of marijuana. It is a reaction to poor growing conditions where a female plant “feels” that there is a poor chance of a natural fertilization of its buds by an external male. As a result, the plant will take the dramatic emergency measure of producing both male & female flowers in a last ditch effort to reproduce itself.
Biochemically, a marijuana plant carrying the gene for this behavior is able to invoke this survival reaction through internally elevating the levels of gibberellic acid being created by the plant. Gibberellic acid (also called Gibberellin) is a potent naturally occurring growth hormone that regulates various processes of plant development. In some plants (such as grapes) ellevated levels of gibberellic acid can cause an increase in the size of the fruiting structures. The effect on marijuana when levels are elevated is the creation of male flowers on an otherwise female plant.
How the Sex of a Seed is Determined Genetically
Plants are either male or female depending on the two-chromosome combination of the X and Y chromosomes. A male carries an X and a Y chromosome (“XY”, while a female carries two X chromosomes (“XX”. When pollenization of a female plant occurs, the seeds and how the sex characteristics are determined is based on a simple combination of the two sets of chromosomes:
Male
X Y
-----------
Female X | XX XY
X | XX XY
From this Mendel Square, you can see that there are 4 possible combinations of the chromosomes from the male and female plant that a seed can inherit, 2 being male (“XY” and 2 being female (“XX”, representing a 50% chance a seed will be male or female. As a side note scientifically this suggests that strategies of producing more female plants from seeds by germinating and vegetating the plant under certain conditions to improve the female:male ratio are ineffective, as the seed’s sex is predetermined when it is created based on the chromosome distribution outlined above. However, there are known cases of plants being able to alter sex based on environmental conditions, but this is outside the scope of what I am covering here.
What is a Feminized Seed?
From what we have seen above, the definition of a feminized seed is a seed where the sex chromosome combination is guaranteed to be “XX”.
It is common in the marijuana seed industry to sell feminized seeds that are simply the result of a hermaphrodite self pollinating. Technically, this is a feminized seed because both “parents” are contributing “XX”, resulting in seeds that can only have an “XX” combination as the “Y” chromosome is not in the equation. Pollen of a hermie female still passes “XX”, pollen itself is only a chromosome distribution mechanism and will still pass the chromosomes of the plant on which it is produced. In the case of a true male where pollen is naturally produced this is “XY”, with a hermaphrodite female plant this is still “XX”. Hermie male flowers are a reaction to environmental stress, they do not represent a fundamental rewriting of the plants genetic characteristics.
If the plants resulting from a hermaphrodite-sired seed are not stressed, there is every probability that a healthy female plant will be produced. The mother created seeds without the contribution of a male, thus the male chromosomes are not present in the offspring. The drawback of this method is that the seeds created are also guaranteed to have the hermaphrodite trait passed, resulting in a risk of your garden being destroyed by hermie male flowers spreading pollen and destroying the potency of your crop. Sometimes this manifestation of male flowers is very slight – only a couple of male flowers hidden within predominantly female buds. However this is still enough pollen being produced in the environment to effectively destroy a harvest.
(Continued...)
Below is my mental consolidation of the information I have uncovered in regards to making feminized seeds correctly, and hopefully this outlines how the members here can try making them for themselves. To be clear, I am in the process of doing this, and the article I have put together below is not based on experience but rather research. A peer review from the group will hopefully find any flaws in my logic or statements I have made, but I feel the article I have put together is based on generally accepted principles. You be the judge
Background – Marijuana Reproduction
First, some background. Marijuana is what is known as a gonochorist reproducer, meaning it has two distinct sexes of individuals (both male and female), similar to humans. This is uncommon in the plant world, where most flowering organisms are predominately hermaphrodite, having both male and female reproductive structures on the same plant. A look at a typical daylily clearly illustrates this as the female pistil is surrounded by male pollen producing stamen.
In the world of marijuana cultivation hermaphrodites do exist. While not the natural state of the plant, a hermaphrodite (or “hermie” as they are colloquially known), is a marijuana plant that produces both male & female flowers. This is a very undesirable characteristic in the context of growing marijuana for the harvesting of THC as a hermie can ruin an entire crop of what would have been sensimilla female buds due to pollen distribution in the growing environment. The pollen will fertilize any female flowers that it lands on, thus dramatically reducing the THC contents of the bud as the female plant redirects its energy from producing sticky THC to catch pollen to seed production, which have no appreciable THC content.
The hermie genetic trait is thought to be a survival characteristic of marijuana. It is a reaction to poor growing conditions where a female plant “feels” that there is a poor chance of a natural fertilization of its buds by an external male. As a result, the plant will take the dramatic emergency measure of producing both male & female flowers in a last ditch effort to reproduce itself.
Biochemically, a marijuana plant carrying the gene for this behavior is able to invoke this survival reaction through internally elevating the levels of gibberellic acid being created by the plant. Gibberellic acid (also called Gibberellin) is a potent naturally occurring growth hormone that regulates various processes of plant development. In some plants (such as grapes) ellevated levels of gibberellic acid can cause an increase in the size of the fruiting structures. The effect on marijuana when levels are elevated is the creation of male flowers on an otherwise female plant.
How the Sex of a Seed is Determined Genetically
Plants are either male or female depending on the two-chromosome combination of the X and Y chromosomes. A male carries an X and a Y chromosome (“XY”
, while a female carries two X chromosomes (“XX”. When pollenization of a female plant occurs, the seeds and how the sex characteristics are determined is based on a simple combination of the two sets of chromosomes:Male
X Y
-----------
Female X | XX XY
X | XX XY
From this Mendel Square, you can see that there are 4 possible combinations of the chromosomes from the male and female plant that a seed can inherit, 2 being male (“XY”
and 2 being female (“XX”, representing a 50% chance a seed will be male or female. As a side note scientifically this suggests that strategies of producing more female plants from seeds by germinating and vegetating the plant under certain conditions to improve the female:male ratio are ineffective, as the seed’s sex is predetermined when it is created based on the chromosome distribution outlined above. However, there are known cases of plants being able to alter sex based on environmental conditions, but this is outside the scope of what I am covering here. What is a Feminized Seed?
From what we have seen above, the definition of a feminized seed is a seed where the sex chromosome combination is guaranteed to be “XX”.
It is common in the marijuana seed industry to sell feminized seeds that are simply the result of a hermaphrodite self pollinating. Technically, this is a feminized seed because both “parents” are contributing “XX”, resulting in seeds that can only have an “XX” combination as the “Y” chromosome is not in the equation. Pollen of a hermie female still passes “XX”, pollen itself is only a chromosome distribution mechanism and will still pass the chromosomes of the plant on which it is produced. In the case of a true male where pollen is naturally produced this is “XY”, with a hermaphrodite female plant this is still “XX”. Hermie male flowers are a reaction to environmental stress, they do not represent a fundamental rewriting of the plants genetic characteristics.
If the plants resulting from a hermaphrodite-sired seed are not stressed, there is every probability that a healthy female plant will be produced. The mother created seeds without the contribution of a male, thus the male chromosomes are not present in the offspring. The drawback of this method is that the seeds created are also guaranteed to have the hermaphrodite trait passed, resulting in a risk of your garden being destroyed by hermie male flowers spreading pollen and destroying the potency of your crop. Sometimes this manifestation of male flowers is very slight – only a couple of male flowers hidden within predominantly female buds. However this is still enough pollen being produced in the environment to effectively destroy a harvest.
(Continued...)
