Homozygous cannabis seeds
Although we will keep it simple, there are a few basic terms that one must know in order to understand the concepts we will talk about in this article.
Genotype: This is the genetic makeup of an organism. it describes an organism’s entire set of genes. This is not something you can directly observe.
Phenotype: Also known as “Pheno”. A phenotype encompasses all the physical characteristics based on genotype. That is what growers can observe with their own eyes. For instance: Size, bud color, leaf shape… Note that the same plant can express different phenotypes based on the environment/growing conditions.
Alleles: The Alternative versions of a given gene are called alleles. Most cannabis plants have 2 different versions of each gene.
Heterozygous: having two different alleles of a particular gene or genes. Example: A plant that has 1 allele coding for broad leaves and 1 coding for narrow leaves may either produce broad leaves, narrow leaves or something in-between.
Homozygous: having two identical alleles of a particular gene or genes. For instance, a plant that has 2 alleles coding for purple flowers will produce purple flowers.
Why Make A Strain Stable?
For example, if you won the prestigious High Times Cannabis cup with a new “strain”, many growers may then want to grow that same outstanding strain. However, if that strain has not been properly stabilized, your chances of finding that same incredible plant from a 10 pack of seeds are slim to none.
In order to have uniformity among the offspring, it takes much more than a one-off cross.
Stability here refers to genetic stability meaning that the plants are homozygous for most genes. It is not to be confused with sexual stability (Having pure males and pure females without any hermaphrodites).
That being said, sexual stability is also an essential component. During the selection and stabilization process, plants must go through stress-tests in order to reveal their hermaphroditic tendencies. Then, all the “Hermies” must be culled out.
How Can You Stabilize A Strain?
There are several different methods breeders resort to in order to stabilize their strains.
Cannabis Plants by nature are diploids with twenty chromosomes. When you pollinate a plant, each one of the parents contributes ten chromosomes each to the new cell they have formed.
Selfing is a method that consists of pollinating a plant with itself (Generally a female plant). To do so, the breeder would have to reverse (Make a female produce male flowers) a branch of that female by spraying Colloidal Silver or Silver Thiosulfate (STS). Then, one can collect that female pollen and use it to pollinate the other branches of the same plant.
Selfing a female plant will only produce female seeds.
Each self’ed generation leads to an increase in characteristics by 50%. In other words, each time you self a plant, the genetic stabily (Homozygosity) will increase by 50%.
Selfing a cannabis plant is the fastest way to stabilize a strain. However, it is also the fastest way to lose vigor.
Backcrossing consists of crossing a plant with one of its parents (The recurrent parent). Meaning that a chosen plant among the offpring will have to be crossed back with the same parent each time. By doing so, breeders can achieve offspring with a similar genetic identity to that of the chosen parent (Recurrent parent). This is how the breeder “Mr Soul” created the famous Cinderella 99 using an outstanding Jack Herrer plant as the recurrent parent.
The advantage of backcrossing is that unlike the selfing method, you can still work with both male and female plants at the same time.
The biggest disadvantage is that by using this method, breeders can only fix a trait if the recurrent parent is already homozygous for the gene coding for that specific trait.
Line Breeding (Inbred lines):
IBLs are strains that breed true for a certain number of traits. A true breeding strain will have only one main phenotype with very little variations. IBL plants also have a uniform genotype.
To create a true breeding strain, cannabis breeders have a specific list of traits they are after. Then, they work with large populations of plants in order to find plants that would express these traits. Once the breeder has found a male and a female (Or 2 females) that match his criteria, he will make seeds with them. Then, the same process starts all over again with the offspring. It takes several generations to create a true breeding strain. Generally at least 5. However, you cannot focus on too many traits at the same time because it is very unlikely to find several specimens expressing the same group of traits. The bigger the population a breeder works with, the more traits he or she can focus on at once. Although breeding requires skills and knowlege, it is also a numbers game!
A Slow Process:
Some Landraces are almost true breeding because they have been selected by farmers for certain specific qualities over many generations. On the flip side, polyhybrids require much more work in order to become genetically stable. These are full of genetic diversity and genetically unstable. Therefore, it may require over 10 generations for a polyhybrid to become an IBL.
You can create an very stable line by inbreeding your plants, thus creating an inbred line (IBL). To create an IBL, one must keep records and cull out all the plants which don’t match his list of criterions.
Regular IBLs Versus Feminized IBLs:
Cannabis breeding is often a slow process. Nonetheless, line breeding is much faster and yields great results when working with female plants only. Line breeding using both male and female cannabis plants is trickier for 2 reasons:
- It is often hard to know what female attributes a male can pass on. The best way to know is to grow each male’s offspring but this is very time consuming.
- Male plants don’t “Herm” (turn hermaphrodite) as easily as female plants. For that reason, it is harder to stress-test them.
Line breeding for many generations leads to the creation of new IBL strains.
You can also cross 2 distinctly different IBLs to produce a new, uniform phenotype also known as a true F1 Hybrid.
True F1 Hybrids:
Many plant breeders and expert growers see True F1’s as the holy grail of breeding. True F1’s are sought after because the are both uniform and highly vigorous. True F1’s are the result of a cross between 2 stable lines (IBLs) that are genetically very different from each other. Despite the fact that both parents are very different, the offspring will look very stable.
Because each parent is highly homozygous, it always passes on the same version of a given gene to its offspring. That is why, all the true F1 plants that have the same parents will have almost the same combination of genes. That explains why true F1’s are very uniform even if they are heterozygous. Furthermore, true F1’s are more vigorous than either parent because of the principle of Heterosis (Hybrid Vigor). Having 2 different alleles for each gene is what causes that incredible Hybrid Vigor.
Just like true F1s, F1s are the offspring of two genetically different plants. However, unlike true F1s, the parents of an F1 do not have to be genetically stable (IBL) for making an F1.
Unlike true F1’s that are created using 2 very stable lines, F1’s are often very unstable. Because their parents are not homozygous but heterozygous. As a result, there will be many different combinations of genes among the offspring. Although F1’s are generally vigorous, there won’t be one main pheno but many. When we talk about pollen chucking, we refer to the creation of F1 Hybrids. These are your typical “One-off crosses”.
When creating a true-breeding strain, plant vigor sometimes decreases to the point where breeders have to either backcross, or go back one or several generations in order to regain some vigor. That is because when plants become too heavily inbred, they become genetically weak and they grow much slower. By the same token, genetically weak plants can develop undesirable mutations. Selfing a cannabis plant is the fastest way to stabilize a strain but it is also the fastest way leading to inbreeding depression.
Can Home Breeders Achieve Great Results?
While it is true that professional cannabis breeders are more likely to create good stable strains, home breeders can definitely create new outstanding varieties as well.
As mentioned before, cannabis breeding does not only take skills and knowledge but it is also a numbers game. For that reason, home breeders would have to focus on only one line at a given time. They can optimize their grow space and use small containers to maximize the number of plants. With the right experience, a lot of discipline and a great deal of patience, home breeders can also obtain amazing results.
The world of cannabis breeding is full of surprises and anyone with a solid breeding strategy has the potential to create the next Skunk#1…
If creating a new strain seems daunting to you, don’t be afraid, take it step by step and be patient.
Good luck with your future breeding endeavors!!
Development completed of fully stable and genetically uniform cannabis hybrid seeds
CanBreed has completed the development of a stable and uniform Cannabis hybrid seed. In doing so, the company brings a solution to the main problem of the Cannabis industry that suffers from a lack of uniformity and standardization due to the absence of genetic stability in Cannabis plants resulting also in high production costs that hamper growers’ profits. Stable and uniform hybrid seeds, with improved genetics, are the solution to both these problems.
In June 2020, after more than three years of strenuous research and development, CanBreed completed the development of the first uniform homozygous (100% stable) Cannabis parental lines. Crosses between these parental lines creates the world’s first true F1 hybrids Cannabis seeds. The company has completed the first F1 hybrid seed production cycle in the world. These stable hybrids will ensure the reproducibility, standardization and high quality of raw material for the entire Cannabis industry.
In the present cycle, CanBreed produced dozens of stable new varieties from diverse genetic backgrounds, which will be planted for testing in CanBreed’s breeding and seeds production farm that is at its final stages of construction. At the end of the selection phase, which is expected to be completed during the first half of 2021, the seeds of the varieties that fit industry demands will be marketed.
Unlike most agricultural crops that are grown from stable seeds, Cannabis plants are presently propagated vegetatively through cloning by using cuttings from mother plants. Cloning is done in order to ensure genetic identity between the offspring and the mother plants, which until now could not be achieved by growing Cannabis from seeds because there were no stable Cannabis seeds.
The main cause of the lack of standardization that exists in the industry is that the raw material extracted from Cannabis plants grown from cuttings is not reproducible. On one hand, cloning ensures a genetic identity between the offspring and the mother plant, but on the other hand, the cloning methods that exist today (such as tissue cultures) do not prevent the aging of the mother plants. Thus, similar to the natural aging processes that take place in any living organism (including humans) mother plants accumulate aging related mutations and changes in the genome that cause differences in the chemical profile of the plant. This leads to the fact that despite being genetically identical, the chemical profile of offspring differs from those of the young mother plants.
The reason that until now it was not possible to get reproducible and uniform Cannabis products by growing Cannabis from seeds is that all Cannabis strains in the market today are heterozygous (genetically unstable) and crossing between two unstable Cannabis strains will produce seeds with high genetic variation. Thus, today every seed grown on a plant produced from the crossing of two unstable plants is genetically different from all the other seeds on the same plant. The fact that all the seeds are different from each other in a particular Cannabis plant means that plants grown from these seeds, even though they originated from the same plant, will have a different genetic profile. Therefore, to this day, the only method available for Cannabis growers to preserve the genetic identity of the offsprings has been through cloning of mother plants.
The solution to the problem comes from the seeds industry.
In the agricultural industry, plants, such as tomatoes, corn, watermelon, etc, are grown exclusively from stable seeds thus ensuring genetic uniformity that enables high quality growing and reproducibility of the products.
Stable seeds, such as tomato seeds, corn, etc. used in the agricultural industry, are produced from homozygous parental lines (plants that are 100% genetically stable). The procedure of creating homozygous plants requires dedicated resources, unique agronomic and scientific knowledge and consumes considerable time. Crossing of two different homozygous plants will produce seeds that are genetically identical, meaning that all the resultant seeds of the crossing will have the same DNA (identical twins). These seeds are known in the seed industry as F1 Hybrid seeds. Using F1 Hybrid seeds will always result in plants identical to each other, thus eliminating the need for cloning of Cannabis and Hemp and ensuring the reproducibility and uniformity of the raw material extracted from the plant.
In parallel to the development of stable seeds, CanBreed is developing YieldMaxTM, an enhanced genetic trait platform, which contains all the agronomic traits that Cannabis and Hemp growers need for consistent, high-quality, cost efficient mass-scale cultivation. The breeding of the YieldMaxTM traits is achieved by using CRISPR-Cas9, an innovative gene editing technology. Upon completion of the YieldMaxTM development, the stable seeds of CanBreed will contain also these traits.
At November, CanBreed announced that as part of its project to develop a Powdery Mildew resistance trait, which is one of the traits in the YieldMaxTM platform, the company performed and identified an editing event in the Cannabis plant genome using CRISPR-Cas9. This report follows the company’s announcement on signing a commercial license agreement for CRISPR-Cas9 foundational patents with the CRISPR patent owners – Corteva Biosciences and Broad Institute (of MIT and Harvard). The CRISPR developers were recently awarded with the Nobel Prize in Chemistry for 2020.
The company further announced recently that it had purchased a 3.5-acre farm in San Diego county in California. A production facility of stable hemp seeds intended for the US market is planned to be set-up at the farm. The farm’s initial output is expected to be about 12.5 million seeds annually, which will subsequently increase to about 50 million seeds annually.
Ido Margalit, CanBreed CEO: “The company’s achievement comes after nearly four challenging years of development as the company faces extensive knowledge and infrastructure gaps in the field of Cannabis seeds, and in parallel invests in market education regarding the feasibility of developing stable Cannabis and Hemp seeds. CanBreed’s achievement, first of its kind in the world, positions the company at the forefront of this emerging industry that will provide a solution to a huge global potential market of Cannabis and Hemp seeds, estimated at hundreds of millions of dollars a year”.