Backcrossing VS Bx1

Pheno hunting is one of the most exciting and rewarding endeavors in cannabis cultivation, but it’s just the first step for home breeders. Testing large populations in different environments is enjoyable, and discovering something truly unique is always exhilarating. However, when you come across that exceptional plant with standout traits, the real work of preserving its genetics begins. At this point, breeders face a choice between asexual propagation and sexual reproduction.

While it’s possible to keep the plant in a vegetative state indefinitely and clone it continuously, there are several risks involved. Mother plants can suffer from insect infestations, viral infections, and mistakes in watering and spraying. Moreover, grow rooms can be subject to theft, and growers themselves may face illness or legal issues. Power outages and various other unforeseen circumstances can also disrupt the cultivation process. Despite genetic reservoirs and backup clones held by friends, I have unfortunately lost several clone-only strains over the years. However, those strains that were bred are not lost; they live on through their offspring.

Older clone mothers often experience “genetic drift” and phenotypic changes, requiring growers to adapt their grow environments to accommodate specific phenotypes. This approach is more labor-intensive compared to adapting the plants to the environment. When I come across a special line worth preserving, I aim to breed it to thrive in various outdoor and indoor environments and accommodate different grow methods. My goal is to create seeds that work for any grower, capable of withstanding mistakes and challenges. Adaptability holds more importance to me than uniformity.

Seeds are much easier to store for long-term preservation and can remain viable for hundreds of years when properly stored. Additionally, seeds can be easily shared with friends in different states and countries, unlike clones, which can encounter difficulties during transportation. Breeding your special female plant offers the added advantage of further improvement and adaptation to different environments and stressors, as well as the benefits of “hybrid vigor.”

Once we find that exceptional plant, we can play matchmaker and search for the perfect male partner. This process often brings some of the most rewarding breeding experiences. However, conducting a male pheno hunt is impractical for most breeders due to plant limits. Usually, breeders have to select the best male out of only two or three options. In such cases, many of the desired traits are likely to be recessive in their offspring. Hunting for those specific seeds becomes necessary to identify the individuals we desire and continue breeding that line for multiple generations until the traits we seek become predominant. Backcrossing offers a faster and simpler method to stabilize these recessive traits.

Backcrossing (BC) involves taking a plant, known as the donor parent, and crossing it with any one of its ancestors, referred to as the recurrent parent. This increases the likelihood of expressing recessive traits present in both parents, including the desired unique traits. However, it can also lead to the expression of undesirable recessive traits, which may require further selection and line-breeding to keep in check.

In the cannabis breeding community, there is a specific form of backcrossing known as “Bx1.” In Bx1, a plant is bred with a clone of one of its parents, typically the mother. This approach serves as a shortcut to “stabilize” a cultivar, providing a higher level of genetic uniformity than what can be achieved in a single generation of breeding.

Often, breeders take Bx1 seeds and cross them with the mother-grandma plant to create Bx2 seeds. Repeating the process leads to Bx3 seeds, and some breeders even go as far as Bx4 and Bx5. However, it’s important to note that, like all forms of inbreeding, extended backcrossing can result in mutations presenting themselves, along with a loss of vigor and resistance, especially if the original strains used in the breeding project were closely related. To address this, breeders can introduce parallel lines to cross with each other after a few generations of inbreeding, promoting genetic diversity.

For home breeders with limited space or plant limits seeking to preserve a special phenotype, Bx1 is the ideal option. It serves as an excellent first breeding project for those capable of maintaining a plant in the vegetative stage and can be completed in under six months. A successful Bx1 can become the foundation for many outstanding strains.

Happy breeding, and may your endeavors be fruitful and fulfilling!