“There really is no genetic basis to require males in a Cannabis breeding program.”
With the advent of chemically-induced sex reversal techniques, the above attitude towards breeding with true male plants is becoming more common. I don’t think we know enough about the male’s contribution to cannabis breeding to support this statement. There is the phenomenon of sex-linked traits, and we are just at the beginning of exploring what those traits may be. There could be critical traits that aren’t visually apparent which are passed on through males – disease resistance, for instance – that could be lost in a female-only breeding program, apart from the inevitable slide toward dominate expression of intersexuality, i.e., sinsemilla apocalypse….
There are many instances of sex-linked traits passed from one sex that is expressed in the opposite-sex progeny. In humans, male-pattern baldness is the well-known example. Again, having only mapped the cannabis genome in the last couple of years, the state of the science here is in its infancy, and any position that “males don’t matter” is based more on ideology than biology. We simply don’t know what alleles code for what traits in cannabis, yet.
Breeder selection is the primary evolutionary pressure placed on drug cannabis today. Among “feminized” seed breeders, there is much talk about using only “fully female” plants to avoid passing on intersexuality tendencies. So, what is a “fully female” plant? How does one select for “full femaleness”? Is that really what a feminized seed breeder is selecting for?
No, s/he is not. The feminized breeder selects parent stock primarily based on those individuals which will express intersexuality when exposed to stress, whether from chemicals, dark period disruption, or water and nutrient deficiencies. Any female plant that cannot express male traits, i.e. produce staminate growth with viable pollen, simply will never make the cut in a female seed production project. Therefore, the feminized breeder intentionally, and as a primary trait, selects for intersexual expression.
S/he may select carefully, looking for those individuals who tend to express intersex traits only under severe stress, but select she does. Any truly “fully female” individuals which do not express intersexual traits under extreme stress will be culled from the program by their very virtue of being unable to form male flowers with viable pollen. Feminizers aren’t selecting for “fully female” plants, they are culling them, because they won’t “flip.”
Therefore, any feminized plant breeding program, by its very nature, will select and breed for individuals with an ever-increasing frequency of intersexual expression in the offspring, by the very nature of the breeder’s selection – conscious or unconscious.
I’ve heard this “fully female” argument from feminizers for years. It’s bunk pure and simple. Sexuality, in animals and plants, is expressed along a spectrum. It is only binary at the chromosomal level. Chemicals don’t change genes, they simply change the level of environmental stress, which the plant responds to based on its genotype. Those plants with genotypes that favor intersexual expression form pollen sacs. Only those plants which form pollen sacs get feminized. Feminized breeders select for hermaphrodism, plain and simple.