What Are Hybrid Strains? How Breeders Mix Indica, Sativa and Ruderalis

A hybrid strain is cannabis bred by crossing two or more varieties so the offspring combines the traits of its parents, and today the vast majority of strains on the market are hybrids. Through breeding and crossing, they've become very different, in both phenotype and genotype, from the ancestral landrace strains. The goal is to stack the best qualities of each parent into one improved plant.

Hybrids are basically humanity's big attempt at custom-built plants with specific traits, usually drawn from ruderalis, indica or sativa varieties. Hybrid weed is in high demand because it inherits the best qualities of its parents.

What types of hybrid strains are there?

Generally, crosses are said to fall into four types:

• Sativa x sativa: a cross between two sativa strains.
• Indica x indica: a cross between two indica strains.
• Sativa x indica: a strain described this way is a sativa-dominant hybrid, though it has traits from both cannabis families. It might be a tall plant with purple buds, for example.
• Indica x sativa: this strain will have traits of both, but it's indica-dominant.

On top of that, autoflowering hybrids are strains that were crossed with ruderalis genetics at some point in their history.

Hybrid genetics: dominant and recessive traits

Genetic inheritance is the genetic information that comes from the parents, gets combined and is passed down. Even though a plant gets genetic information from both parents, only the dominant genes show up in how it looks. That gives us two scenarios:

• Complete dominance: this happens when a dominant gene completely controls how a trait looks over a recessive gene. Simply put, if a trait is dominant, it shows up in the plant's appearance, while a recessive trait stays hidden. For example, if one parent carries green as a dominant trait and the other carries purple as a recessive trait, under complete dominance the first generation will be entirely green.
• Incomplete dominance: this happens when neither gene is fully dominant, so the resulting phenotypes can show a blend of both. It's less common and can produce in-between traits in the first generation and the ones after it, an exception to Mendel's simple dominance rule. Going back to our cannabis example, the offspring would show a mix of green and purple tones instead of a single color.

Landrace weed and the cannabis subspecies

Landrace weed refers to cannabis types that humans domesticated in the past but that adapted to different regions, where they can now grow “wild” without human intervention (also known as open pollination). That's why these varieties tend to come from remote places, usually mountain regions.

There are three main types of cannabis that emerged as landrace genetics in different parts of the world, and then there are cannabis hybrids:

Indicas:

Indica plants are compact and short and pump out lots of resin with dense buds. Some indica landraces, like Kush, have moderate levels of THC and other cannabinoids, plus plenty of myrcene, a terpene known for its relaxing effects. Many indica landraces are adapted to harsh mountain environments and are used to breed tough, compact strains.

Sativas:

Sativas are known for growing into tall, tree-like plants with airier buds than indicas. These towering plants come from regions like Mexico and South Africa. Durban Poison, for example, is a one-of-a-kind South African strain that contains THC, THCV and a significant amount of terpinolene, which gives it a distinctive peppery, herbal flavor.

Ruderalis:

Ruderalis is native to Central Asia and Eastern Europe, has low THC and one unique trait: it doesn't depend on the photoperiod to flower, meaning it blooms regardless of how much light it gets. That trait is hugely valuable commercially. Whenever you find an autoflower version of your favorite hybrid, you'll know it was made by crossing indica or sativa genetics with ruderalis.

Hybrids:

These cannabis varieties come from humans crossing the subspecies above. Breeders combine indica, sativa and/or ruderalis genetics to create hybrids that highlight the traits breeders, growers and consumers want. An early commercial hybrid was Skunk, considered one of the first “major” indica-sativa crosses, though it wasn't the only one.

How are hybrid strains made?

Crossing two plants might sound simple, but getting a specific result in nearly all the offspring with some degree of stability is a whole different story. Cannabis breeders can tackle each project with different methods, including:

Compensatory mating

This method combines the desirable traits of two different plants so the offspring inherit the best of both, reducing or offsetting any weaknesses. Even if one parent lacks certain qualities the other has, this process can make up for it.

Directional selection

This means identifying the traits you want in a phenotype and locking them in through stabilization. Put simply, you cull the plants you don't want and focus on the ones that show the specific trait you're after.

Producing regular seeds

This is one of the simplest jobs, but it's up to nature. You just expose female plants to pollen from a male plant, and they'll produce seeds. Keep in mind that with this approach, the offspring will be highly variable.

Creating a new hybrid depends on several factors, including experience and patience. How you handle them affects the final quality and stability of the hybrid. That's why it's crucial to understand what stability means in this context.