What are F1 Seeds? What about F2, F3, etc?
By Caroline | April 22nd, 2024
With a little help, anyone can be a grower. But becoming a breeder is an entirely different ball game.
Breeders often devote their entire careers to creating that one perfect cross. They achieve this by enhancing the strongest properties through selection and crossbreeding. These crosses are indicated by generation.
Let's discuss what F1, F2, F3, etc selections are.
What are hybrid cannabis strains?
The demand for new cannabis species is increasing with the natural consequence that there is plenty of experimentation by breeders.
As a result of this (cross) breeding and experimenting, most of the species on the current commercial market are hybrids. These are plants that are a result of crossbreeding several cannabis varieties to amplify certain effects or characteristics.
As this crossing process evolves, the plants will eventually form seeds from different cannabis strains or generations.
Cannabis, like any other plant, exists as a pure variety or as a hybrid mix of strains.
Hybrids are the result of attempts to shape plants with specific characteristics, which are common in ruderalis, Sativa, and Indica strains. Successful crosses inherit the best traits of both parents.
When the industry started to commercialize, both pure varieties and existing hybrids were constantly mixed and recombined. These efforts have produced some of the best-known species today.
What are F1, F2, F3, etc. selections?
As you further specialize in cannabis cultivation, you will undoubtedly encounter more and more impressive terminology.
When I first saw the term "F1 strain", I seriously wondered what car racing and cannabis have to do with each other (and if it was wise to combine the two).
Needless to say, the guys got a good laugh out of that one. It turns out it has nothing to do with the automotive sports industry, nor should we fear for Hamilton's safety.
In this case, F1 means something totally different and very fascinating!
In a nutshell, an F1 variety is the first hybrid plant from a specific pair of parents and a new phenotype that is
independent, yet still closely related to the two parents.
But that just sounds confusing and doesn't cover the load. Let's go further back first before we take a leap into the unknown...
Creating new cannabis strains
The basics of growing plants are always the same. This also applies to cannabis. Male pollen pollinates the female plant. Nature has ensured this happens naturally.
But when creating a hybrid, the growers use selective breeding in a controlled environment. This entails that the breeder personally selects the female plant and the male pollen in order to get one or more specific characteristics in the offspring.
A few of the properties that can be improved through selection are rooting, growth potential, flowering period, color, bud structure, and yield.
The seeds germinated after this process are the first generation of hybrids from male and female parents. The plants with the desired characteristics undergo this selective process again.
Once the desired traits are achieved, the breeder stabilizes the species.
The next step is crossing the young hybrid with the parent species to enhance the characteristics.
This process requires a lot of patience and perseverance from the breeder since stabilizing the properties of a species usually requires three or more generations.
We distinguish the following generations:
- Pure Breeding strains
- F1
- F2
- F3
- F4
- F5
- IBL
To make a well-informed decision when deciding on what the ideal seeds for you, it is helpful to understand the differences between these different generations.
Pure-breeding line or strain
A group of identical individual plants that always produce offspring of the same phenotype when intercrossed.
Pure-breeds are unadulterated traditional landraces that have only interbred with similar strains and so have almost identical genes.
F1 – The first grow
F1 stands for "first-generation hybrid". The F derives from Filius, which is the Latin word for "son". Yes, botanists sure love their Latin ;-)
You create an F1 strain by crossing two pure strains with completely different phenotypes. To achieve this, the grower will, for example, take 100 of their best plants and select only the very best mother plants based on a specific trait from one strain.
He will do the same with another (pure) species.
Let’s take a large plant (represented by two dominant genes, AA)
and cross it with a small but bushy plant (represented by the two
small recessive genes, aa). Since the resulting plants each receive
one gene from each parent, this will result in offspring with the following genetic makeup: Aa. All four offspring have the same makeup and will each be tall bushy plants.
The difference from the parent generation, in this case, is that these will not be pure strains due to the presence of the recessive gene.
F2 - Keep on crossing
To create an F2 strain, the breeder will cross two members of the F1 family together.
The offspring that comes from this crossing has
the genetic makeup of AA, Aa, AA, and aa.
That means that the F2 seed variety will have three tall plants and one short plant. So, the main difference between the F1 and F2 varieties is the amount of genetic variation and purity of the seed strain.
F3 - Reducing variation
As the cycle continues, we keep combining plants with the desired traits. We call this generation: F3. For example, if the grower was looking for short plants, he would select parents with the composition of Aa and aa.
The result of this combination is two tall plants, each with the genetic markers of Aa, and two short plants (both aa). This breeding has actually reduced the variation towards a more stable variety. We call this process stabilizing.
Since F3 varieties usually start of rather unable we advise to cross it back with the selected F2 mother plant.
F4 - Narrowing the number of phenotypes
Once you've achieved a level of stability in your F3 variety, it is time to take your game to the next level. By continuing the selection process and using only the most stable plants from the previous generation, we've now reached the F4 variety.
F4 varieties contain even fewer phenotypes, which means that the plants should be nearly identical, with only slight variations in, for example, scent or yield.
F5 - Perfecting the process
By continuing on this path of crossing the strongest plants back within their own generation, the stability grows and a strong new species has emerged.
IBL Strains
After F5, the plants are IBL.
IBL stands for “inbred line”, AKA the holy grail of cannabis cultivation.
An IBL is a breed that produces offspring with stable and consistent genetics usually from a single dominant phenotype of the strain.
These strains will produce balanced and homogenous offspring with the desired specific characteristics time and time again for many generations.
Creating a stable F1 strain
When you pollinate a feminized female plant with pollen of the male-cannabis plant, you will get seeds, but not automatically a stable strain.
Breeders create stabilized hybrids and then continually interbreed, stabilizing their characteristics from generation to generation.
There are very few strains of stabilized hybrids as the process takes a number of generations, over several years, to achieve.
It is important to note that ‘stable’ is not the same as ‘true-breeding’. A true-breeding strain will produce consistent offspring of one dominant phenotype. In marijuana strains, you can mainly find this in landraces.
If you want to create a stable strain that shows the generation of the same characteristic after generation, you will have to stabilize it by crossing it back various times. By always selecting and crossing plants with the desired characteristics, you stabilize a species.
Since this is a time-consuming technical process that demands a lot from the breeder, it's now clear where the -sometimes- massive price difference for different types of seeds comes from.
Let's recap...
F1 is the result of crossing 2 separate varieties. The resulting seeds are F1 and they will be stable, meaning the plant qualities should be pretty consistent.
All the plants from these seeds will be very similar. This is great if you prefer a crop of identical plants.
F2 is a cross of 2 of your F1 plants from the seeds you bred. F2 is what true breeders are looking for.
The F2 seeds are unstable meaning the plants grown can show very different qualities, some may be good while others are bad. The F2 seeds can contain all the possibilities of phenotypes from all of the previous lineages of both parents.
F2's are where you will find the next great strains which is what true breeders are consistently trying to do along with producing stable seeds for its consumers.
Once you find that special F2 plant, you need to cross it with another F2 from the same seed batch. Next, cross this plant back with your special F2. The seeds from this, called F3 will be unstable and may not produce your special F2 consistently.
To stabilize your new strain (The special F2 plant you selected) you now grow F3 seeds and pick one of these to back cross with your F2 mother.
The resulting seeds from this will be an F4 and more stable than F3 seeds. You continue this process to about an F5. By this time the F5 seeds should be stable and look like the new breed F2 that you found. You have now created your very own new strain!
So the main difference between F1, F2, and F3, etc. is simply the generation and level of stability that comes with them.
With each successive selection, the grower selectively takes the plants that are the best representation of the properties he desires and uses them for crossings.
I hope this has given you some insight and clarity and brought you are one step closer to being a full-fledged Marijuana high school graduate. Happy growing
Caroline
Educated by one of the best breeders in the Netherlands, I chose to combine my passion for writing with the fascinating world of cannabis cultivation. What are the best strains for which occasion, what are the effects, and how to use responsibly? Let me take you on a journey.
