## 3 Discussion
### Phenotyping in Terms of THC and CBD Composition
[PERSON] and colleagues (2020) stated that, while the THC content in light cannabis has to be within 0.2%, CBD content is highly variable, ranging from 2 to 40% [41]. Additionally, serum THC/CBD concentration ratio was used as a useful biomarker to identify use of light cannabis (not higher than 0.9), illegal THC cannabis (generally \(>\)10), and medical cannabis (\(>\)1) [35]. Another study on chemotaxonomic discrimination indicated significant chemical differences in three chemotypes, so that CBD dominant varieties had higher amounts of total CBD, while THC dominant varieties had higher total THC, and intermediate varieties were generally equal to or in between those in CBD-dominant and THC-dominant varieties [58]. They finally showed that chemotype markers (presence or absence of THC and CBD) could be used as chemical fingerprints for quality standardization or variety identification for clinical studies and cannabis product manufacturing [58]. THC and CBD variations among populations of this Iranian collection enabled us to define studied populations as three different groups: Type I (THC/CBD \(>\) 1), Type II (THC/CBD \(\approx\) 1), and Type III (THC/CBD \(<\) 1) with a prevalence of THC, both THC and CBD in an approximately equal proportions, and CBD, respectively (Figure 3a). Genetic diversity in Iranian cannabis germplasm has been assessed by merging the data with the marijuana and hemp data prepared by [59] to elucidate the relationship of Iranian cannabis with marijuana and fiber type accessions. Finally, they categorized Iranian cannabis populations into marijuana and hemp clusters and reported that natural populations of cannabis in Iran in general more closely fit the profile of marijuana than hemp [60]. Additionally, in this study, we have used the same sources to fingerprint THCand CBD, and these populations were defined as Type I, Type II, and Type III, thus revealing, on the basis of chemistry, these three distinct types. In this research, most plants of population Ard-01, which were also morphologically distinct with a THC/CBD ratio around one due to equivalent THC and CBD concentrations, were assigned to class Type II, defined as an intermediate THC/CBD ratio. This supports the findings of a genetic diversity study reported earlier, indicating Ard-01 was failed to group with either the marijuana or hemp clusters [60]. This is an interesting finding and may have immediate significance for commercialization, promising for therapeutic purposes in the production of medications with formula requirement of THC/CBD ratio around the unity such as Sative\({}^{\circledR}\)[61]. This is an important medication for the suppression of spasticity and pain associated with multiple sclerosis [13; 62]. It is worth noting that sequencing the whole genome of this morphologically, chemically, and genetically distinct population would be of value, as this should provide further insight into the genetic basis of the three chemotypes described here. Furthermore, a concentration of THC \(\leq\) 0.3% and higher amount of CBD in the plants from the location Sam-01 that was located in class Type III is another significant finding in this study, worthy of further investigation, and may reflect a tight control of cannabinoid type and content for cultivation and could provide pre-breeding germplasm resources for future development of hemp crops, particularly in nations where there is a strict regulatory environment around the production of high THC crops. Although most of the focus has been on identifying plants with higher concentrations of THC for the recreational drug industry, and those with higher concentrations of CBD for medicinal, fiber, and grain purposes, there is also evidence reporting therapeutic benefits for CBD with anticonvulsive, anti-epileptic, antimicrobial, and antiparkinsonian properties, which are more important recently due to the lack of psychotropic effects associated with CBD consumption, as well as FDA-approved CBD drugs such as Epididex\({}^{\circledR}\)[63; 64; 65; 66; 67; 68].