Most commercial cannabis varieties are diploid, meaning they possess two sets of chromosomes, one from each parent plant. Through selective breeding, new triploid and tetraploid forms of cannabis are being cultivated with increased potency, unique traits, and improved vigor. In this post, we’ll look at how manipulating the number of chromosomes impacts cannabis genetics and what benefits triploid and tetraploid strains may offer growers and consumers.
Chromosomes and Cannabis
All living organisms contain chromosomes within each cell, which carry the genes and DNA sequences that determine traits and enable reproduction. Cannabis plants normally have 20 chromosomes, with 10 contributed from the male pollen and 10 from the female flower to create offspring. This is known as diploid cannabis. The number of chromosome sets is reflected in scientific names, with diploid cannabis being Cannabis sativa 2n=20.
Creating Triploids and Tetraploids
Through advanced breeding techniques, the number of chromosomes can be manipulated to produce triploid and tetraploid plants. These variants have 50-100% more chromosomes compared to the standard diploid form. Here’s an overview:
Triploids – Contain three sets of chromosomes, denoted as 3n. Most triploids have 30 total chromosomes.
Tetraploids – Four sets of chromosomes, denoted as 4n. Tetraploids typically have 40 chromosomes.
Creating these aneuploid chromosome numbers requires crosses utilizing genetics that produce unreduced gametes, either diploid pollen or tetraploid ovaries. The resulting seeds produce triploid or tetraploid offspring.
So what’s the purpose of producing triploid and tetraploid cannabis breeds? While individual results can vary, reported effects include:
- Increased vigor – More chromosomes provide genetic redundancy that can improve plant size, growth rates and yield. Triploids and tetraploids are often more robust and resilient.
- Higher cannabinoid levels – The extra chromosomes allow for additional THC and CBD production resulting in elevated cannabinoid concentrations.
- Greater resin content – Research has shown aneuploids can increase resin gland density and overall cannabinoid production.
- Novel appearances – Unusual phenotypes are possible, like extremely wide leaves or fatter buds. The odd chromosome numbers can bring out unique expressions.
- Seedlessness – Many triploids and most tetraploids produce little to no viable seeds, a desirable trait for commercial growers.
- Distinct effects – Anecdotal reports describe more complex aromas and effects from triploid and tetraploid strains. The novel genetics may recombine cannabinoids in new ways.
- Of course, negative results like decreased vigor or yield are also possible depending on the individual strain and growing conditions. But skilled breeders select the most promising polyploid specimens for reproduction.
Notable Breeders and Strains
While still somewhat rare, a number of reputable cannabis breeders have dabbled in the aneuploid arena and released unique triploid or tetraploid hybrids:
- Symbiotic Genetics – Produced Zkittlez T1, a triploid version of their famous Zkittlez strain touted to have 50% higher cannabinoid levels.
- Seed Junky – Known for elite clones like Wedding Cake, Seed Junky has created several tetraploid crosses using their genetics, including 4N MAC.
- Compound Genetics – Released TetraMAC, a potent, seedless tetraploid cross of Miracle Alien Cookies and Starfighter.
- Canna Exotics – Known for breeding large, vigorous polyploid specimens under their TetraHybrix brand. Strains include Double Strawberry Yeti V2.
- Thug Pug – Famed breeder Gromer crossed his elite Glue stud “Studley Spewright” to a tetraploid female to produce Tetraploid Gorilla Glue, an ultra-potent tetra.
The aneuploid cannabis scene is still emerging but shows intriguing potential for creating the next generation of super strains. As breeders refine techniques and stabilize polyploid genetics, growers can look forward to big, resiny new varieties along with intriguing cannabinoid profiles. The cannabis chromosome count continues increasing in the quest for optimum potency.
Eastman, Michael. “What Are Cannabis Triploids and Tetraploids?” Leafly, 21 Oct. 2021, https://www.leafly.com/news/science-tech/what-are-cannabis-triploids-tetraploids
“Polyploid Cannabis Types: Tetraploid and Triploid.” RQS Blog, 6 May 2020, https://www.royalqueenseeds.com/blog-polyploid-cannabis-tetraploid-and-triploid-n861
Clarke, Robert Connell. “Tetraploid and triploid cannabis genetics.” Extract, 6 Apr. 2018, https://extract.suntimes.com/extract-news/tetraploid-triploid-cannabis-genetics/
Loo, Michelle. “Tetraploids: Coming Soon to a Grow Near You.” Cannabis Now, 26 Aug. 2021, https://cannabisnow.com/tetraploids/
Kessler, Michael. “Hunting Tetraploids.” High Times, 14 Mar. 2019, https://hightimes.com/grow/hunting-tetraploids/
We’ve gathered a list of recommended tools and resources for growing Cannabis plant, which you can find in our post How Long Does It Take To Fully Grow A Cannabis Plant?
To learn more about Cannabis Clones, we’ve written extensively about it in our posts on From Clone to Harvest: Understanding The Journey of Cannabis, Legalizing of Four Cannabis Plants per Household in Canada, and How Can Cannabis Clones Save Me Money and Time.