Male Selection in Cannabis Breeding
Male selection is one of the most critical aspects of breeding quality Cannabis seed that sadly, is becoming a lost art. Although the majority of the Cannabis community has largely begun to look at the male half of our precious herb as obsolete due to the ubiquitous nature of genetic medication, ie. chemical feminization, this trend should be viewed as incredibly short sighted and potentially disastrous for ensuring genetic diversity.
The simple fact of the matter is that we have yet to fully understand the role of the male chromosome in Cannabis, apart from sexual propogation, and in doing away with males altogether, we laugh with self-assured hubris that us humans know better than Mother Nature; a dangerous and slippery slope.
With that being said, here are some techniques that we apply here are Lucky 13 Seed Company in order to ensure that every generation of our seed lines continue to improve over the previous iteration.
#1 Large Selection Numbers: The first mistake pollen chuckers and basement breeders make is thinking that you can develop a great seed line from a couple pack of seeds with only a handful of males to work with. Sure, you can make some seeds to play around with for next season, but unless you grow out a large number of males you will have absolutely no clue if the pollen donor you have selected is actually an exceptional example that will strengthen the line. If you skip this crucial step and end up selecting a poor example from the gene pool, every successive generation will pay the price. I recommend selecting from an absolute minimum of 20 strong males, while we prefer starting with 50-100 and then culling heavily until we're left with only the absolute standout examples with the traits that we want to propagate in the line.
#2 Flowering Males to Absolute Completion: Patience in breeding is key, and letting your pollen donors flower to complete maturity requires patience and planning. It is not enough to flower your males for a few weeks until the initial pollen drop, then fertilizing the females and calling it a day. Many males will not show their true potential until late into their flowering cycle (past week 6 of bloom) and you could inadvertently be eliminating the best examples of the line when you chop your males too soon. This requires flowering the males well in advance of your female pollen recipients in order to allow enough time for them to fully express their qualities. Since you will often not know the sex of your plants until you begin the flowering cycle, this requires taking clones of the entire population, flowering them in separate locations to completion, making your selections for both males and females, and then doing a second crop for seed by flowering only the keeper males and females together. This is time consuming and can take upwards of 6-12 months to do properly. Therefore, be cautious of any seed company who releases multiple brand new seed lines every few months. Unless they are working with a male breeding clone with a proven track record, chances are they are just using the "spray and pray" method.
#3 Discard Earliest Flowering Phenotypes: Sometimes selecting your males for the earliest flowering phenotypes can be desirable; in the case of breeding for an earlier flowering plant for short-season climates for example. However it is often the case that the very first males to initiate flowering and reach maturity correspond to the least potent chemotypes. This is another reason why employing large selection numbers is crucially important to breeding quality high-potency cannabis. If you only have a few males to choose from, you have no idea what their relative flowering time is like compared to the overall population.
Additionally, many breeders suffer from what I call "first-flower bias" and pick the first male that reaches maturation as their breeding stud. This is because, in comparison to the later flowering phenotypes, the first male to flower will reach full maturity first, and will deceptively look like the largest yielder. However, if left to mature completely the remaining phenotypes can reach, and often surpass, the yield of the first flowering male, and with a much greater potency potential. Ultimately, if first-flower bias is employed over the long term, the genetics will favour less potent progeny with each successive generation.
This doesn't mean you always want to select the very last male to flower either, as these can be genetic outliers that may do nothing but extend the flowering time of the progeny unnecessarily. Typically when selecting our males we will flower a very large population, discarding the earliest and slowest flowering phenotypes, and hunt for a stud that matches our breeding criteria in the mid-to-late range to ensure peak potency and reasonable flowering times.
#4 Eliminating Male Intersex Traits: Oh the dreaded 'herm', how you are so maligned. The fact is that genetically modified feminized Cannabis seed is far more likely to produce male pollen then well-bred natural cannabis seed. The reason for this is that in order to be effectively feminized, the line has to already be prone to intersex traits in order for the procedure to work. Certain lines simply refuse to produce viable male pollen and can't be feminized which is why these special plants tend to be passed around as clone-only elite strains. This does not mean that all feminized seed will 'go herm', and there are certainly many good breeders who produce quality feminized seed and put in the work of thoroughly testing their progeny to eliminate these negative traits.
However, when breeding organic Cannabis seed, careful attention must be paid to the male selection in order to eliminate any potential intersex traits. While most growers have seen female hermaphroditism, far fewer have seen this expressed in the male side of the equation. It is not as uncommon as you might think, but it often will not reveal itself until much later in the life cycle of the male, generally past the point that many breeders will keep their pollen donors, which is why it is more evasive. It can sometimes be a little tricky to see, but will reveal itself as female stigmas emerging out from a male pollen cluster, often after week 5 or 6 of flowering. When we find this expression in a male plant, it is discarded from the breeding pool as the likelihood of it producing offspring with intersex traits is quite high.
NOTE: Occasionally you may find a plant that initially expresses as male, but then produces abundant female flowers. These unique plants will often take on the appearance of a female plant that has been sex-reversed with feminizing chemicals. There is some debate amongst Cannabis breeders about these intersex males and their ability to produce high percentages of female progeny. In my experience, if you find a plant that initially expresses as male, but then produces heavy female flower clusters for the remainder of its life cycle, the pollen from this plant is likely to produce a very high percentage of female offspring and not necessarily with intersex traits. In this case the plant seems to be a male that leans heavily the female side. I've seen this repeatedly over the years with a particular phenotype of Romulan that pops up occasionally, as well as Chocolate Indica. If you do happen upon such a plant, the only way to know for sure what you're dealing with is to grow out large numbers of the offspring to look at sex percentages and potential hermaphroditic qualities.
#5 Selecting Males for Resin Production: While stem rubs can be useful in helping to determine what types of terpene profiles males will pass on genetically, truly exceptional males will actually produce resin glands later in the flowering cycle. If and when these resin glands appear, a simple pinch and rub between your fingers will release a much headier and nuanced bouquet that will provide a much clearer picture of the terpene profile encoded in the male's DNA. These resinous males also translate to resinous females, and very often correspond to potency potential as well. Yet again, this requires letting the males flower past 6 weeks in most cases, as well as growing out a large numbers since this trait can be somewhat elusive. Pictured below is a great example of a resinous male from our upcoming Romulan X line. This is a special Romulan IBL that has been line bred by over a decade of exploring multiple generations and hundreds of phenotypes of this legendary cultivar. Many males were sifted through and discarded in order to lock down these unique traits of enhanced resin production, purple stems and flowers, improved structure, and otherworldly potency.