Contributed by MrSoul:
Breeding fine cannabis involves carefully choosing the breeding stock. To choose wisely we must first define male and female cannabis:
Female Cannabis – The female cannabis plant, unlike the male, is grown to produce marijuana. Premium marijuana is produced in seedless form by eliminating all pollen sources from the growing environment. Seed production reduces the value of marijuana dramatically by lowering the yield and potency of the flowers. Hermaphrodites are plants expressing both male and female flowers. They may fool a grower who mistakes the "hermie" for a female - only to find his crop is ruined by the unexpected release of pollen. Knowledgeable marijuana breeders are very careful to avoid hermaphrodism in their seedlines.
The attributes of a valuable female are the following (in descending order of importance):
1. Resistance to hermaphrodism
5. Rate of flowering response
6. Resin production
9. Floral structure
10. Floral color
Male Cannabis – The male cannabis plant is essentially only useful for breeding. The male plant makes very poor marijuana, being mostly leaves without the dense resinous floral clusters of the female the yield is miserable. More importantly, the male of the species has virtually no potency in comparison to that of female cannabis. The males do carry genes that influence the expression of ALL the traits listed above, but not many of them are directly observable in the male itself due to the male phenotype being markedly different from the female phenotype. A male cannabis plant’s value is DEFINED by the quality of his daughters.
Naturally, when starting out with a large number of potential breeding individuals, one desires to “weed out” the undesirable individuals.
The female is easy to evaluate because all the traits favoring marijuana production are directly observable in the female. It's a simple matter of growing & flowering the females to grade their performance and smoking the resulting marijuana. The breeder then chooses only those females most closely matching the breeder's personal ideal to be used as seed parents.
The directly observable & important traits of male cannabis are as follows:
1. Resistance to hermaphrodism
4. Maturation rate
All males expressing poor quality in any of these traits should be culled so as not to pass the weak trait on to the progeny.
Males are also be observed to have a certain scent and floral structure but the importance of these traits pale in comparison to those listed.
The potency of male plants, and especially the potency difference between individual males in a group, is generally too subtle to be measured by anything short of professional scientific laboratory equipment. Moreover, there is no conclusive proof that the most potent male in a group actually creates the most potent female progeny, although it seems intuitive that that should be the case. The difficulty of determining a male plant's potency is a major hurdle to proving this link.
Thankfully, logic dictates that the potency of a male plant ITSELF isn’t very important, as we aren’t interested in growing males for marijuana production. The value of a male lies entirely in the traits he consistently passes on to his daughters. Therefore it’s unnecessary to identify the one male amongst a group of potential pollen donors with the greatest potency. It’s far more logical to evaluate the female progeny of each male to define the potency of each male in the group.
Male cannabis individuals may be graded for quality by a controlled pollination of IDENTICAL female clones (one for each pollen donor). This isolates the influence of the male by holding CONSTANT the influence of the female on each cross. The seeds resulting from each clone are then grown and the progeny is graded to determine which of the crosses was the most successful. When the group with the most desirable female progeny is identified, the responsible male has been identified as the most valuable. Males can be kept in the vegetative state exactly like female “mother plants”, except that we should call them “dads” of course. Clones from the favored male can be flowered as needed along with the breeding female(s) when seeds are desired.
Due to the clandestine nature of marijuana growing, in most cases there will only be about 10 males to be evaluated after culling all those with directly observable defects. Breeding with larger populations is always preferable, as genetics is a statistical "game".
Commercial breeders would clearly benefit from the development of a reliable method of identifying males with the greatest potential for passing on high potency genes. Perhaps someone will do the necessary research someday, but by following the above method, growers can accurately pin-point the ONE male in their small group which is the most potent...in the only meaningful sense of “male potency”.