Gender vs Sexual expression
Quote:
Originally Posted by
Chimera 
What seems like an easy question to answer is complicated by growers who don't understand the difference of gender vs sexual expression.
Dioecious varieties have
staminate and
pistillate individual, said another way males and females.
Gender is set in stone at
fertilization, gold star for amanda88. Rather, the gender is set in the chromosomes.
Males are identified by the presence of a Y chromosome, ie XY plants.
Females, on the other hand lack a Y
chromosome, or are XX genetically at the
sex chromosome (pair #10). Cannabis has 10 pairs of chromosomes, one of each pair inherited from mom, one of each pair from dad.
It is the male that either deposits, via
meiosis, the Y or X
chromosome into the pollen grains. If it donates an X
chromosome containing pollen grain to the
ovule of the female, the resulting seed is male (XY). If the male donates an X containing pollen grain, the resulting seed is female (XX). Said again another way, if the male donates a Y to the seed, the resulting offspring is male. If the male donates his X
chromosome to the seed, the resulting progeny is genetically female.
~
In monoeicious varieties, ie
hemp varieties that are intersex, we see an interesting thing happen.
When you genetically test the plants bearing staminate flowers for the presence of a Y chromosome, there is none present. You see these varieties are essentially a mix of females, and intersex plants (known incorrectly as hermaphrodites), but
there is a lack of true males or XY plants. How can this be? These varieties are used for the production of nutritional
hemp seed, so they must be shedding pollen and self-fertilizing the population. But no true male XY plants exist in the population?
What is happening is that these plants have a
series of genes that allow the formation of
staminate flowers on genetically female plants- what dope growers call herms (again, correctly referred to as intersex). The
staminate flowers shed pollen, and the nearby females and even pollen shedding plants set seed on their
pistillate flowers, and seeds are produced.
These genes make up what we call in genetics a QTL- or quantitative trait loci- which are essentially a series of genes or genetic factors, which taken together, all contribute to the level of intersexuality on a plant.
If a plant has only a low dose of the particular genes in a female plant, you might get a female that occasionally sprouts a
staminate or male flower- either constitutively (ie, the plant sprouts male flowers throughout the flowering-cycle), or it may only sprout a
staminate flower near the end of flowering. This is the sexual expression of
staminate flowers on genetically female plants, and not to be confusd with true males.
At the other end of this spectrum, you might see a plant that has many of these genetic factors for producing
staminate flowers on genetically female plants, to the point that a genetically female plant, may even produce more
staminate (ie male) flowers that it does produce
pistillate (female) ones. Again, this is an example of sexual expression of
staminate flowers on a
female gendered (XX) plant. It pretty easy for a grower to look at this plant and say "it's a male", especially considering many growers only look at the first few flowers to determine sex. Think about it, most growers see the first few male flowers at the base of a young plant from seed, decide it's a male, then kill it. However to call this plant a male, is incorrect; genetically it's a female plant that produced male flowers.
The true test of maleness is the presence of a Y chromosome, which can only be tested microscopically (very difficult and labour intensive in cannabis) or via genetic means, either
PCR or
DNA sequencing, which are now very easy and inexpensive tests.
