How many strains of cannabis are there

In this research, we examined commercially available, drug-type Cannabis strains using genetic methods to determine if the commonly referenced distinctions are supported and if samples with the same strain name are consistent when obtained from different facilities. Samples were examined to determine if there is any genetic distinction separating the commonly referenced Sativa, Indica and Hybrid types and if there is consistent genetic identity found within strain accessions obtained from different facilities.

The analyses revealed genetic inconsistencies within strains, with most strains containing at least one genetic outlier. However, after the removal of obvious outliers, many strains showed considerable genetic stability. We failed to find clear genetic support for commonly referenced Sativa, Indica and Hybrid types as described in online databases. Significant genetic differences within samples of the same strain were observed indicating that consumers could be provided inconsistent products.

These differences have the potential to lead to phenotypic differences and unexpected effects, which could be surprising for the recreational user, but have more serious implications for patients relying on strains that alleviate specific medical symptoms.

Cultivation of Cannabis sativa L. The U. Global restrictions have limited Cannabis related research, and there are relatively few genetic studies focused on strains Lynch et al.

Currently, the Cannabis industry has no way to verify strains. Consequently, suppliers are unable to provide confirmation of strains, and consumers have to trust the printed name on a label matches the product inside the package.

Reports of inconsistencies, along with the history of underground trading and growing in the absence of a verification system, reinforce the likelihood that strain names may be unreliable identifiers for Cannabis products at the present time. Without verification systems in place, there is the potential for misidentification and mislabeling of plants, creating names for plants of unknown origin, and even re-naming or re-labeling plants with prominent names for better sale.

Cannabis taxonomy is complex Emboden ; Schultes et al. Leafly b and various levels of recent legalization in many states has led to a surge of new strains Leafly a ; Wikileaf Breeders are producing new Cannabis strains with novel chemical profiles resulting in various psychotropic effects and relief for an array of symptoms associated with medical conditions including but not limited to : glaucoma Tomida et al.

There are primarily two Cannabis usage groups, which are well supported by genetic analyses Lynch et al. Within the two major groups Cannabis has been further divided into strains varietals in the commercial marketplace, and particularly for the drug types, strains are assigned to one of three categories: Sativa which reportedly has uplifting and more psychotropic effects, Indica which reportedly has more relaxing and sedative effects, and Hybrid which is the result of breeding Sativa and Indica types resulting in intermediate effects.

The colloquial terms Sativa, Hybrid , and Indica are used throughout this document even though these terms do not align with the current formal botanical taxonomy for Cannabis sativa and proposed Cannabis indica McPartland ; Piomelli and Russo We feel the colloquial terminology is necessary here as the approach for this study was from a consumer view, and these are the terms offered as common descriptors for the general public Leafly a ; Wikileaf ; cannabis. Genetic analyses have not provided a clear consensus for higher taxonomic distinction among these commonly described Cannabis types Lynch et al.

However, both the recreational and medical Cannabis communities claim there are distinct differences in effects between Sativa and Indica type strains Leafly a ; Wikileaf ; cannabis. Female Cannabis plants are selected based on desirable characters mother plants and are produced through cloning and, in some cases, self-fertilization to produce seeds Green Cloning allows Cannabis growers to replicate plants, ideally producing consistent products.

There are an overwhelming number of Cannabis strains that vary widely in appearance, taste, smell and psychotropic effects Leafly a ; Wikileaf ; cannabis.

Online databases such as Leafly a and Wikileaf , for example, provide consumers with information about strains but lack scientific merit for the Cannabis industry to regulate the consistency of strains.

Other databases exist cannabis. To our knowledge, there have not been any published scientific studies specifically investigating the genetic consistency of strains at multiple points of sale for Cannabis consumers. Breeders and growers choose Cannabis plants with desirable characters phenotype related to flowers, cannabinoid profile, and terpene production.

Phenotype is a product of genotype and environment. Cannabis is considerably variable and extraordinarily plastic in response to varying environmental conditions Onofri and Mandolino Therefore, determining sources of variation, at the most basic level, requires examining genetic differences. Strains propagated through cloning should have minimal genetic variation.

Eight of the strains examined in this study are reportedly clone only strains indicating there should be little to no genetic variation within these strains.

That being said, it is possible for mutations to accumulate over multiple generations of cloning Gabriel et al. Self-fertilization and subsequent seed production may also be used to grow a particular strain.

With most commercial plant products growers go through multiple generations of self-fertilization and backcrossing to remove genetic variability within a strain and provide a consistent product Riggs However, for many Cannabis strains, the extent of genetic variability stabilization is uncertain.

It has been observed that novel Cannabis strains developed through crossing are often phenotypically variable Green , which could be the result of seed producers growing seeds that are not stabilized enough to produce a consistent phenotype. Soler et al. Given the uncertainties surrounding named Cannabis strains, genetic data provides an ideal path to examine how widespread genetic inconsistencies might be. In the U. Traditionally, morphological characters were used to define new varieties in crops such as grapes Vitis vinifera L.

With the rapid development of new varieties in these types of crops, morphological characters have become increasingly difficult to distinguish.

Microsatellite genotyping enables growers and breeders of new cultivars to demonstrate uniqueness through variable genetic profiles Rongwen et al. Microsatellite genotyping has been used to distinguish cultivars and hybrid varieties of multiple crop varietals within species Rongwen et al.

Generally, 3—12 microsatellite loci are sufficient to accurately identify varietals and detect misidentified individuals Cipriani et al. We used a well-established genetic technique to compare commercially available C. This study is highly unique in that we approached sample acquisition as a common retail consumer by purchasing flower samples from dispensaries based on what was available at the time of purchase. All strains were purchased as-is, with no additional information provided by the facility, other than the identifying label.

This study aimed to determine if: 1 any genetic distinction separates the common perception of Sativa, Indica and Hybrid types; 2 consistent genetic identity is found within a variety of different strain accessions obtained from different facilities; 3 there is evidence of misidentification or mislabeling.

Cannabis samples for 30 strains were acquired from 20 dispensaries or donors in three states Table 1. All samples used in this study were obtained legally from either retail Colorado and Washington , medical California dispensaries, or as a donation from legally obtained samples Greeley 1. Several databases exist with various descriptive Sativa and Indica assignments for thousands of strains Additional file 1 : Table S1. For this study proportions of Sativa and Indica phenotypes from Wikileaf were used.

Analyses were performed on the full sample dataset Table 1. The 30 strains were assigned a proportion of Sativa according to online information Table 2.

Results from popular strains are highlighted to show levels of variation in strains that are more widely available or that are in higher demand. Primers were developed de-novo flanking microsatellites with 3—6 nucleotide repeat units Additional file 1 : Table S2. Seven of the microsatellites had trinucleotide motifs, two had hexanucleotide motifs, and one had a tetranucleotide motif Additional file 1 : Table S2.

Ten primer pairs produced consistent peaks within the predicted size range and were used for the genetic analyses herein Additional file 1 : Table S2. For all strains the r- mean and standard deviation SD was calculated averaging among all samples. Obvious outliers were determined by calculating the lowest r- mean and iteratively removing those samples to determine the relatedness among the remaining samples in the subset.

A graph was generated for 12 popular strains Table 2 to show how the r- mean value change within a strain when outliers were removed. The microsatellite analyses show genetic inconsistencies in Cannabis strains acquired from different facilities. While popular strains were widely available, some strains were found only at two dispensaries Table 1.

Since the aim of the research was not to identify specific locations where strain inconsistencies were found, dispensaries are coded to protect the identity of businesses. There was no evidence of linkage-disequilibrium when all samples were treated as a single population. All loci deviate significantly from HWE, and all but one locus was monomorphic in at least two strains. All but one locus had excess homozygosity and therefore possibly null alleles.

Given the inbred nature and extensive hybridization of Cannabis , deviations from neutral expectations are not surprising, and the lack of linkage-disequilibrium indicates that the markers are spanning multiple regions of the genome. The number of alleles ranged from 5 to 10 across the ten loci Additional file 1 : Table S2. There was no evidence of null alleles due to scoring errors. Division into two genetic groups does not support the commonly described Sativa and Indica phenotypes.

Each strain includes reported proportion of Sativa in parentheses Wikileaf and each sample includes the coded location and city from where it was acquired. Each bar indicates proportion of assignment to genotype 1 blue and genotype 2 yellow. Strain types with the same reported proportions are the same color but have different symbols. The PCoA of all strains represents Different symbols are used to indicate different strains within reported phenotype.

Coordinate axis 1 explains Comparisons are detailed for six popular strains Fig. Values of close to 1. Negative values arise when individuals are less related than expected under normal panmictic conditions Moura et al.

Sample strain names and location of origin are indicated along the top and down the left side of the chart. Pairwise genetic relatedness r values are given in each cell and cell color reflects the degree to which two individuals are related. Standard deviations ranged from 0. The strains with higher standard deviation values indicate a wide range of genetic relatedness within a strain, while low values indicate that samples within a strain share similar levels of genetic relatedness.

In order to determine how outliers impact the overall relatedness in a strain, the farthest outlier lowest pairwise r- mean value was removed and the overall r- means and SD values within strains were recalculated Table 3.

In all strains, the overall r- means increased when outliers were removed. In strains with more than three samples, a second outlier was removed and the overall r- means and SD values were recalculated. Overall r- means are displayed for all 30 strains Table 3 , and graphically for 12 popular strains Fig.

Initial overall r- means indicate only three strains are first or higher order relatives Table 3. Removing first or second outliers, depending on sample size, revealed that the remaining samples for an additional ten strains are first or higher order relatives 0. However, removal of two outliers, Denver 1 and Garden City 2, reduces the number of comparisons ranked as not related from 13 to zero. This graph indicates the mean pairwise genetic relatedness r initially light purple , and after the removal of one medium purple or two dark purple outlying samples in 12 popular strains.

Cannabis is becoming an ever-increasing topic of discussion, so it is important that scientists and the public can discuss Cannabis in a similar manner. We postulated that genetic profiles from samples with the same strain identifying name should have identical, or at least, highly similar genotypes no matter the source of origin. The multiple genetic analyses used here address paramount questions for the medical Cannabis community and bring empirical evidence to support claims that inconsistent products are being distributed.

An important element for this study is that samples were acquired from multiple locations to maximize the potential for variation among samples. Maintenance of the genetic integrity through genotyping is possible only following evaluation of genetic consistency and continuing to overlook this aspect will promote genetic variability and phenotypic variation within Cannabis. Addressing strain variability at the molecular level is of the utmost importance while the industry is still relatively new.

Genetic analyses have consistently found genetic distinction between hemp and marijuana, but no clear distinction has been shown between the common description of Sativa and Indica types Lynch et al. We found high support for two genetic groups in the data Fig.

If genetic differentiation of the commonly perceived Sativa and Indica types previously existed, it is no longer detectable in the neutral genetic markers used here. Extensive hybridization and selection have presumably created a homogenizing effect and erased evidence of potentially divergent historical genotypes. Wikileaf maintains that the proportions of Sativa and Indica reported for strains are largely based on genetics and lineage Nelson , although online databases do not give scientific evidence for their categorization other than parentage information from breeders and expert opinions.

This has seemingly become convoluted over time Russo ; Clarke and Merlin ; Small a ; Small Our results show that commonly reported levels of Sativa, Indica and Hybrid type strains are often not reflected in the average genotype. This analysis indicates strains with similar reported proportions of Sativa or Indica may have differing genetic assignments. From these results, we can conclude that reported ratios or differences between Sativa and Indica phenotypes are not discernable using these genetic markers.

Given the lack of genetic distinction between Indica and Sativa types, it is not surprising that reported ancestry proportions are also not supported. To accurately address reported variation within strains, samples were purchased from various locations, as a customer, with no information of strains other than publicly available online information.

Evidence for genetic inconsistencies is apparent within many strains and supported by multiple genetic analyses. These results indicate that half of the included strains showed relatively stable genetic identity among most samples.

Six strains had only two samples, both of which were different e. The remaining nine strains in the analysis had more than one divergent sample e. Eight of the 30 strains examined are identified as clone only Table 2. All eight of the strains described as clone only show differentiation of at least one sample within the strain Fig.

Other genetic studies have similarly found genetic inconsistencies across samples within the same strain Lynch et al. These results lend support to the idea that unstable genetic lines are being used to produce seed. Values of 1. Six examples of within-strain pairwise comparison heat maps were examined to illustrate common patterns Fig. Other clone-only strains Clone Only Strains n. Outliers were calculated and removed iteratively to demonstrate how they affected the overall r - mean within the 12 popular strains Table 3 , Fig.

There are unexpected areas in the entire dataset heat map that indicate high degrees of relatedness between different strains Additional file 4 : Figure S3. However, most of the between strain overall r - mean are negative e. These were acquired to include in the study to determine if and how these variants were related.

This illustrates how Cannabis strains may have come to market in a non-traditional manner. Genetic analyses can add scientific support to the stories behind vintage strains and possibly help clarify the history of specific strains. It does, however, produce an autoflower effect, which is why it is used as an additional source of genetic material to give certain breeds this potentially useful characteristic. Ruderalis has an extremely short flowering period, for it is typically found in the Northernmost climates where it is capable of withstanding many harsh conditions with a moderate frost tolerance.

Said to be from parts of Russia, ruderalis typically does not have much time to mature before the cold conditions hit, which plays a factor as to why its flowering period is so quick to occur. In addition to the three primary cannabis species indica, sativa, and ruderalis, these three types are bred and blended together, producing various strain types which are what is often talked about when you go to a dispensary and have a selection to choose from.

In reality, it is actually impossible to say how many cannabis strain types exist in the world — the number could be reaching easily into the millions! This is partially because of an endless number of possible combinations, many of which are still in experimental stages or even bred by small-scale cultivators.

These experimental strain types may never see the light of day and could only be kept for small batch growths, but nevertheless, they are their own unique strain types. Furthermore, it is difficult to test the genetic origins of a specific strain, which is often why some popular selections appear with an unknown genetic origin. Some strain types do stand out above the rest, for they are the most popular.

They are normally classified into families. Here are some of these classifications:. Aside from these four mentioned major group classifications, hundreds of thousands of other cannabis strain types do exist, and many of them have reached immense popularity, while some remain almost completely unheard of.

The variety is honestly quite literally endless. This article is especially tailored to those who were wondering about this commonly discussed question that has existed probably since cannabis first started being widely consumed.

We hope you found this article to not only be entertaining but also educational and informative. It is important to remember that the consumption of marijuana is the sole responsibility of the user and discretion should always be taken. Tobacco vs. WayofLeaf use cookies to ensure that we give you the best experience on our website. If you continue to use this site we will assume that you are happy with it.

Written by Georgia Smith, B. Keep reading to discover how many different kinds of marijuana there are in the world with our informative guide… Understanding Strains: All About the Marijuana Genus Marijuana, the type that we consume and enjoy and that gets us high and gives us these various psychoactive feelings and medical benefits, is known scientifically as the Cannabis plant and is further divided into the three species: Cannabis sativa, Cannabis indica, and Cannabis ruderalis.

The First Species: Cannabis Sativa Cannabis sativa, probably the most commonly recognized of the three species, is by far the largest of the crops.

The Third Species: Cannabis Ruderalis Cannabis ruderalis is the third cannabis species type, but it is definitely the least frequent to be spoken about. Strains of Marijuana: Further Cannabis Classifications In addition to the three primary cannabis species indica, sativa, and ruderalis, these three types are bred and blended together, producing various strain types which are what is often talked about when you go to a dispensary and have a selection to choose from.

The Haze strain type variations tend to be more sativa-dominant, typically with little indica influence. Some of them are, however, officially classified as hybrid strains. Although researchers are studying the effects of a variety of cannabis strains on a range of medical conditions, there is still a long way to go in this area.

All strains of cannabis derive from the Cannabaceae family of plants. Some experts consider that Cannabis indica and Cannabis sativa are the two main subspecies , although some people think they are separate species. To create a strain, cultivators select a variety of traits to produce the effects they want. This is a similar process to how breeders create particular characteristics in dogs. People often describe cannabis strains as being indica, sativa, or hybrid.

Hybrid refers to a strain created by combining both indica and sativa strains. Here are some examples of cannabis strains and the plant they derive from:. Many producers crossbreed cannabis plants to develop new strains with specific characteristics.

Experts suggest that there are over strains of cannabis. One of the most important characteristics of a cannabis strain is the THC content. Some rules exist on naming each strain, but many producers do not name their products according to these rules.

Despite these classifications, hybridization and crossbreeding has meant that people cannot tell exactly how much THC is in a particular plant by simply looking at its physical features. Experts suggest it is impossible to guess the composition of a cannabis plant by looking at its height, branching, or leaf appearance.

The only way to know the chemical composition of a cannabis-derived product is to analyze it in a biochemical assay. However, researchers and scientists remain unsure of the ideal quantities of THC and CBD that people should use for various medical conditions or recreation. Although both THC and CBD are cannabinoids, they act differently in the body because they target different areas in the brain. According to a article , people who use products with a higher THC content may experience psychoactive effects, such as euphoria and a greater sensitivity to things such as color and taste.

However, THC also can lead to anxiety and paranoia. Learn more about what it feels like to be high here. CBD, on the other hand, is non-intoxicating. Some people report mild physiological effects, such as reduced anxiety when using CBD.

Animal studies suggest CBD may help improve vomiting, nausea, pain, and offer neuroprotective effects on the brain. Learn more about the effects of CBD here. However, since CBD can affect mood, some experts describe it as a non-intoxicating but psychoactive compound. Studies are ongoing to determine whether CBD has other physiological effects. Preliminary human data suggests CBD could benefit conditions, such as schizophrenia and even opioid addiction.

The terms indica and sativa derive from the biolgical classification of these species, which is based on physical characteristics.