A science-driven creative process of crossing plants to develop a new plant variety with more desirable traits. Breeding is the backbone of the cannabis industry, especially in recent years with the rise of low-THC, high-CBD hemp plants.
“Breeding of strains with unique properties can take up to five years for large-scale production.”
“At the beginning of the breeding process, hemp breeders use seeds that yield plants with high levels of CBD and low levels of THC.”
More About Breeding
Breeding is the process of crossing a male and female plant, which allows them to pass their genetic information to their offspring. This scientific process aims to produce desirable characteristics and crop varieties with unique and superior traits. Simply put, its goal is to improve the genetic potential of plants.
To understand this targeted process, we should talk about the fundamentals of plant reproduction. The cannabis plant has a diploid genome. This means that it has two copies of each chromosome that houses genetic material. During breeding, each parent provides a copy of their chromosome through the sex cell. Male plants have pollen, and female plants have the ovule. Reproduction combines these cells and mixes the genetic material of both parents in a process known as recombination.
The DNA recombination during breeding is a highly favorable process for future plants because it gives rise to new combinations of traits. Recombination produces new combinations of genes, leading to the appearance of yields that are better suited for new situations. The potential to increase beneficial traits may result in a better-adapted cultivar.
Intentional or targeted breeding is putting one male cannabis plant in a growing chamber with multiple female plants. The chamber can be anything from an enclosed environment shielded with plastic sheets to a specially designed large-scale breeding environment. In this environment, a single male plant pollinates tons of females. Breeders repeat this process for generations to strengthen the genes and assure consistent yields.
The Purpose of Breeding
Cannabis breeding as we know it began in the 1970s. One of the main goals was to increase the potency of cannabis, which was averaging at 3-5% of THC by mass. Modern strains are way more potent, with 17-25% THC by mass. However, other beneficial traits have been harder to acquire. One of them is the unique aroma that makes the product stand out on the market. Another one is the resistance to pests because mold and insects love to feed on cannabis.
It takes time, effort, and resources to yield results from this generational process. Breeders cross a plant that’s vulnerable to pests with a plant that is resistant to pests. The first generation offspring from an initial cross is known as the F1 hybrid. Some of them may display better resistance to pests than others. Next, the good plants are crossed again to further increase the resistance to pests. The second generation is known as F2 hybrids.
Producers use the best plants from each generation and repeat this process to selectively fix these traits. This process can end when the breeder notices that the traits are fixed in the hybrid line and should produce plants identical to them. This happens after rounds of cross-breeding when subsequent generations don’t differ in demonstration of targeted traits seen in earlier generations.
Once breeders create a strain with stable genetics, they sell their seeds to individuals looking to grow a similar crop. But, different people live in different climates, which can affect the outcome of the crop. So, once the seeds are grown in the new climate, the growers pick the ones that adapted better to their environmental conditions. These new plants will be crossed with each other to produce seeds that best adapt to the new environment.
Breeding Hemp CBD
Most countries hopped on the CBD bandwagon, which means they are producing hemp with high CBD levels and low THC levels. A few years ago, the entire focus was on cannabis strains high in THC. Breeders put minimal effort into finding and breeding plants with high CBD concentrations. This is understandable because there was no demand on the market for CBD strains.
Recent progress in research showed the importance and significance of CBD in various medical purposes — without the high. Therefore, producers started developing and stabilizing cannabis strains high in CBD. They use advanced genetic techniques and identification methods. Producers spend years selecting, crossing, and stabilizing unique cannabis strains until they guarantee she contains incredibly high CBD levels and only traces of THC.
Types of Breeding
Breeders use two types of breeding to create products that align with a grower’s goals: inbred and hybrid lines.
A true inbred line encompassess large population of plants from the same strain that are being crossed with one another. This form of breeding homogenizes favorable traits while decreasing genetic diversity because all generations of plants are related to one another. The most extreme form of inbreeding is selfing, which occurs when a plant pollinates itself. When this happens, the plant produces offspring with identical genetics.
Such inbreeding methods have little to no recombination as they often result in lineages that become less vigorous over time. This is known as “stale genetics.” Other breeding methods like outbreeding and backcrossing can re-introduce vigor and diversity in inbred lines.
Outbreeding produces hybrid lines by crossing a true inbred line with favorable traits but less vitality with another true inbred line. When creating hybrids, recombination of vastly different genetic information happens. As a result, hybrids have increased genetic diversity and a healthier lineage known as hybrid vigor. The downside is that the F1s may exhibit new, unwanted traits or some of the parents’ traits, but to a different degree. To fix this, breeders use backcrossing or breeding the F1 generation with the parental plants. This can strengthen the original parental traits in the more diverse hybrids.
One example is the CBD flower Elektra, which is a child of ACDC and Early Resin Berry. ACDC is a well-known cannabis strain that has high levels of CBD and is a stabilized phenotype of the popular strain Cannatonic. Early Resin Berry is a sativa-dominant strain known for its extraordinary fruity flavors. This crossover makes Elektra a CBD powerhouse with high levels of terpenes.
Breeding is a targeted, science-driven process of crossing cannabis plants to develop new strains with more desirable traits. This process was essential for the development of the hemp industry and strains that are high in CBD and low in THC.