Polyploid marijuana: a surprising cannabis mutation

Have you ever heard of polyploid marijuana? It is not a sick plant or a monster from the depths of the ocean, but a type of cannabis that’s genetically different and opens up the door to a whole world of possibilities within the scientific community and the cannabis industry. Here we explain everything there is to know about this plant and how it is produced.

Just like humans, cannabis is a diploid species. This means that its DNA consists of 23 pairs of chromosomes which are located in the nucleus of its cells. Each pair includes one chromosome from the mother and one from the father.

Polyploidy in marijuana occurs when its DNA is grouped into three (triploid), four (tetraploid), or even higher numbers of chromosomes, rather than being grouped into pairs (diploid).

Therefore, polyploid marijuana presents a genetic anomaly, as it has more chromosomes grouped together in its cells, and contains a larger genome than the majority of cannabis plants. So what are the effects of polyploidy in cannabis?

Characteristics of polyploid marijuana

The effects of duplicating a plant’s genome may include larger organs and better stress tolerance. However, whilst polyploidy is widely spread in other crops such as corn and wheat, this is a rare phenomenon in cannabis.

For this reason, a Canadian study published in 2019 analysed the main characteristics observed when introducing polyploidy in marijuana. The results were as follows:

• Larger leaves
• Bigger and less dense stomata
• Denser trichomes
• A distinct terpene profile, with an increase in the number of terpenes.
• Increase in CBD levels
• Same THC levels
• Similar yielding capacity to that of diploid plants.

Does the size of polyploid marijuana matter?

At first glance, this list of features doesn’t seem surprising. However, when a polyploid plant grows in the midst of a cannabis crop, the difference in size is astonishing.

Amongst those growers who have been fortunate enough to witness this strange phenomenon there are rumours of huge buds, boundless leaves, and thicker stems. Polyploid plants stand out so much from their sisters, almost as if they have eaten a couple of the others while no one was looking. This is one of the most characteristic features found in polyploid cannabis, but does size really matter?

Advantages of polyploid marijuana

As you can see, polyploid marijuana only presents a limited number of advantages at present. Although some improvements are there, since there is a clear increase in the number of organs (such as the plant’s stomata and trichomes), these plants do not show a considerable overall improvement when compared to their predecessors. The levels of cannabinoids such as THC and CBD, for example, are very close to those of the original plant.

Nonetheless, this slight improvement in the growth of certain organs can be interesting for the cannabis industry when the plant is grown on a large scale. In this sector, a certain increase in size or a small improvement in cannabinoid levels may lead to great economic benefits.

Furthermore, obtaining a different terpene profile through polyploidy not only expands the aromatic potential of the plant but also opens the door to a world of possibilities for the medical cannabis industry. There is no doubt that the role that terpenes play in the effect of cannabis through their interaction with cannabinoids is becoming more clearly understood.

Is polyploid cannabis found in nature?

Polyploidy is an evolutionary process. This is a frequent phenomenon in plants, especially in flowering species, of which approximately 40% have more than two chromosomes grouped in the nucleus of their cells. Many of these vegetables are also sources of food for humans. Therefore, it is not surprising that this chromosomal abnormality has been unwittingly selected for centuries to generate improvements such as higher yields and larger fruits, among others.

So, the polyploidy of many plants occurs spontaneously in nature, with humans favouring their reproduction until they become the predominant species. However, this isn’t the case for cannabis: to date, only one natural tetraploid of the cannabis plant has been identified.

This was found a few years ago in the cold desert valleys of Lahaul and Spiti, in India. In the style of Indiana Jones and the Raiders of the Lost Ark, a group of researchers found the only tetraploid cannabis variety that lives and reproduces in a natural and spontaneous way in the middle of this arid territory in the heights of the Indian Himalayas. This is documented in their Indian study, published in 2016.

Although cannabis doesn’t have the ability to increase its genome in nature, humans continue to try to apply the benefits of polyploidy in this plant via methods that go beyond the selection of interesting specimens.

The creation of polyploid marijuana

In the last decade, a substantial number of studies have attempted to obtain a stable variety of polyploid cannabis. A Polish study published in December 2021 collects all the efforts that have been made to date to achieve polyploidy in the most sought-after crops, including cannabis. These are the different methods used:

• Colchicine: This drug is used for the treatment of gout and can be very toxic at certain doses, but it also exhibits great antimitotic properties, i.e. it is capable of inhibiting or stopping cell division. Several studies have managed to obtain polyploid cannabis by applying this on the shoots of growing plants.
• Orizaline: As an alternative to colchicine, this herbicide is capable of blocking plant cell growth. Some studies have been able to obtain polyploid cannabis by applying orizaline on small sections of the mother plant in an artificial growing medium (in vitro explants). Hence, orizaline has proven to be a more effective and less toxic agent than colchicine to achieve polyploidy in plants.
• Cross of tetraploid plants with diploid cannabis plants to induce triploidy. The result of this study constituted the first seedless triploid cannabis plants ever created (they essentially cannot produce seeds, even when directly exposed to pollen). Having three sets of clustered chromosomes, there was no equal separation between them to generate sex cells. This type of seedless triploid plant is common in banana, watermelon, hop, and citrus crops.

Polyploid cannabis: on the lookout for better results

History has shown that polyploidy can be a great ally for the creation of high-yielding crops in many plants. However, this reality is still under investigation for cannabis. Many studies have unsuccessfully attempted to achieve a new polyploid cannabis strain that contains more cannabinoids than its predecessors.

Furthermore, many of these have not only failed to achieve an improvement in polyploid plants but have actually obtained a lower THC count in them. This is what happened in a 2017 Iranian study looking to investigate the benefits of polyploidy with regard to the medical applications of cannabis. Judging by the number of research studies that have been conducted around the globe with this objective in mind, we can be sure that polyploid marijuana has a promising future ahead, despite the disappointing results that have been seen so far. We will follow its progress closely so we can give you all the latest news as it emerges.