Sire Lines & "Y" They Matter

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A combined genetic and physical map reveals​

that genes and recombination events are concentrated near chromosome ends​

Genome Res. 2019 Jan; 29(1): 146–156.
doi: 10.1101/gr.242594.118
PMCID: PMC6314170
PMID: 30409771

A physical and genetic map of Cannabis sativa identifies extensive rearrangements at the THC/CBD acid synthase loci​

Comparison of scaffolds between PK and FN assemblies. Alignments of scaffolds from PK and FN FALCON assemblies containing key cannabinoid biosynthesis enzymes are shown. Locations of exons are indicated by pink and blue lines for FN and PK, respectively. Repeat classes given are from RepeatModeler. Individual repeat types indicated were identified by manual analysis. Features of genes are further described and compared beneath the alignments. (A) Aromatic prenyltransferase (AP). (B) THCAS and CBDAS. (C) Olivetol synthase (OLS, or tetraketide synthase).

no equivalent of THCAS (deactivated or not) is found in hemp.

Due to the relatively high rate of polymorphism in cannabis, it should be possible to employ resequencing (e.g., low-coverage short-read Illumina protocols) either on crosses or at a population level to associate variants or variation with traits and genes, using the genetic map.

The scaffold containing CBDAS is located within a much larger repeat-rich and gene-poor region of ∼39 Mb in the central section of Chromosome 6, encompassing 151 scaffolds with no recombination in either parent observed among the 99 F1s (Fig. 1B). The scaffold containing THCAS was separated from this region in a single recombination event among the 99 crosses, thus placing it at one end of this region and indicating that the THCAS and CBDAS scaffolds are at separate loci. We suggest that this repeat-rich segment of the chromosome may have hosted a series of tandem duplications and rearrangements amplifying an ancestral gene, leading to the present chromosomal organization; there is also a pseudogene with 89%–93% identity to each of THCAS, CBDAS, and CBCAS in this region. We note that this observation represents a modification of both previous models of CBDAS and THCAS arrangement: They are not isoforms at an otherwise equivalent locus, and no equivalent of THCAS (deactivated or not) is found in hemp.

Genetic recombination - Wikipedia

en.wikipedia.org

 

[Dime]

,

 

[acespicoli]

,

The Inheritance of Chemical Phenotype in Cannabis sativa L..pdf

drive.google.com

Thats a good read thanks for sharing
ABSTRACT

Four crosses were made between inbred Cannabis sativa plants with pure cannabidiol (CBD) and pure
-9-tetrahydrocannabinol (THC) chemotypes. All the plants belonging to the F1’s were analyzed by gas
chromatography for cannabinoid composition and constantly found to have a mixed CBD-THC chemotype.

Ten individual F1 plants were self-fertilized, and 10 inbred F2 offspring were collected and analyzed. In
all cases, a segregation of the three chemotypes (pure CBD, mixed CBD-THC, and pure THC) fitting a
1:2:1 proportion was observed.

The CBD/THC ratio was found to be significantly progeny specific and
transmitted from each F1 to the F2’s derived from it. A model involving one locus, B, with two alleles, BD
and BT, is proposed, with the two alleles being codominant.

The mixed chemotypes are interpreted as
due to the genotype BD/BT at the B locus, while the pure-chemotype plants are due to homozygosity at
the B locus (either BD/BD or BT/BT).

It is suggested that such codominance is due to the codification by
the two alleles for different isoforms of the same synthase, having different specificity for the conversion
of the common precursor cannabigerol into CBD or THC, respectively. The F2 segregating groups were

used in a bulk segregant analysis of the pooled DNAs for screening RAPD primers; three chemotype-
associated markers are described, one of which has been transformed in a sequence-characterized amplified

region (SCAR) marker and shows tight linkage to the chemotype and codominance.

 

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Four crosses were made between inbred Cannabis sativa plants with pure cannabidiol (CBD) and pure -9-tetrahydrocannabinol (THC) chemotypes.

All the plants belonging to the F1’s were analyzed by gas chromatography for cannabinoid composition and constantly found to have a mixed CBD-THC chemotype.

@Dime this drives it home, home run

@Hammerhead was just mentioning why the potency of cannabis has deteriorated over the years
I remember once in a while and im not talking about all the time we would get some killer weed.
No CBD and it was a magic carpet ride

If I recount the best in the past 35 years theres like 1/2 doz that were special
Were taking out of tons...everyday every year... year after year

Thats saying something ?

The Kerala is overdue...
ah well such is life Best>>>

 

[acespicoli]

Schilling2020_Review_Preprint.pdf

drive.google.com

Phytocannabinoids, synthases, genotypes and chemotypes of Cannabis. Phytocannabinoids are synthesised via a multi-step pathway involving different enzymes. The precursor cannabigerolic acid (CBGA) is first synthesised by a prenyltransferase from the precursor molecules geranyl pyrophosphate (GPP) and olivetolic acid (OA). CBGA is metabolised into tetrahydrocannabinolic acid (THCA) via THCA synthase, into cannabidiolic acid (CBDA) via CBDA synthase or cannabichromenic acid (CBCA) via CBCA synthase. The different synthases are encoded by the BT (encoding for an active THCA synthase) and BD (encoding for an active CBDA synthase) loci. BT/BT plants produce mainly THCA (chemotype I), while BD/BD plants produce predominantly CBDA (chemotype III). Presence of BT and BD results in chemotype II (THCA and CBDA intermediate). B0indicates that only non-functional THCA and CBDA synthases are present, which results in the accumulation of CBGA (chemotype IV). Cannabis varieties with very low overall levels of cannabinoids are categorized chemotype V, which is caused by a homozygous recessive allele of locus O. To complicate matters further, there is also a locus C, which is encoding for CBCA synthase. However, in almost all varieties, CBCA is only produced in young immature flowers. Chemotypes I and II can be considered marijuana, while the other low-THC chemotypes can be considered hemp varieties of Cannabis.

5. The battle of the sexes: Sex determination in Cannabis
5.1. The genetics of sex determination
The dioecy of Cannabis is genetically controlled (Figure 2). Hemp is diploid (2n = 20), with nine pairs of
autosomes and one pair of sex chromosomes. Female plants are homogametic with XX chromosomes and male
plants are heterogametic with an XY sex chromosome pair (Moliterni et al., 2004). Cannabis thus represents
a rare case among the flowering plants in which sex chromosomes have been identified (Charlesworth, 2016).
The diploid genome size of female Cannabis plants is estimated to be 1636 Mbp, that of a male plant 1683
Mbp by flow cytometry (Sakamoto et al., 1998). The sex chromosomes of Cannabis are the largest in the
chromosomal complement, they are estimated to comprise 6.5 % (Y chromosome) and 6.1 % (X chromosome)
13

Posted on Authorea 29 Sep 2020 | The copyright holder is the author/funder. All rights reserved. No reuse without permission. | https://doi.org/10.22541/au.160139712.25104053

Chemotypes I and II can be considered marijuana, while the other low-THC chemotypes can be considered hemp varieties of Cannabis. (Or hay ? @Tom Hill )

 

[acespicoli]

ORIGINAL RESEARCH article​

Front. Plant Sci., 30 June 2021
Sec. Plant Metabolism and Chemodiversity
Volume 12 - 2021 | https://doi.org/10.3389/fpls.2021.699530
This article is part of the Research TopicBehind the Smoke and Mirrors: Reflections on Improving Cannabis Production and Investigating Medical PotentialView all 16 articles

Identification of Chemotypic Markers in Three Chemotype Categories of Cannabis Using Secondary Metabolites Profiled in Inflorescences, Leaves, Stem Bark, and Roots​

Front. Plant Sci., 30 September 2019
Sec. Plant Metabolism and Chemodiversity
Volume 10 - 2019 | https://doi.org/10.3389/fpls.2019.01166
This article is part of the Research TopicThe Origin of Plant Chemodiversity - Conceptual and Empirical InsightsView all 24 articles

Terpene Synthases as Metabolic Gatekeepers​

in the Evolution of Plant Terpenoid Chemical Diversity​

Knowledge of terpenoid-metabolic genes, enzymes, and pathways will increasingly enable the investigation of terpenoid physiological functions in planta and under various environmental conditions. To this end, gene editing and transformation techniques applicable to a broader range of model and non-model species that produce species-specific blends of bioactive terpenoids will be critical (Wurtzel and Kutchan, 2016). Together, advanced genomic and biochemical tools and a deeper understanding of terpenoid biosynthesis and function have tremendous potential for harnessing the natural diversity of plant terpenoids for, for example, improving crop resistance and other quality traits and developing advanced protein and pathway engineering strategies for producing known and novel bioproducts.

 

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Figure 4. Flowering and sex determination metabolic pathways: identification of candidate genes underneath the QTLs. The QTLs for flowering time are found in different flowering dependent pathways (photoperiod, temperature, and endogenous flowering pathways). Photoperiod pathway involves genes of the perception and transduction of light signals [ultraviolet-B receptors (uvr8), circadian timekeeper (xap5), suppressor of PHYA-105 (spa1), cryptochromes (cry1), phytochrome A (phyA), and phytochrome E (phyE)]. Temperature pathway involves vrn1, a vernalization dependent transcription factor. Both photoperiod and temperature pathways activate signaling pathways and/or transcription factors involved in the endogenous flowering pathway to regulate floral meristem identity genes, such as leafy (lfy). Genes that code for these transcription factors include flowering locus C (FLC), flowering locus D (FLD), flowering locus T (FLORIGEN or FT), suppressor of overexpression of constans1 (soc1), and gibberellic acid insensitive (gai gene – DELLA protein), among others. TF is used to summarize all transcription factors inducing floral meristem identity genes. Endogenous pathway also include the regulatory element of flowering genes, miR156. The QTLs for sex determination are found in metabolic pathways involved in regulation of phytohormones gibberellic acid (GA) or auxins. These pathways include B-class homeotic genes involved in the development of male flower organs and auxin response factors genes (ARFs) involved in female flower development.


Front. Plant Sci., 03 November 2020
Sec. Plant Breeding
Volume 11 - 2020 | https://doi.org/10.3389/fpls.2020.569958

Conclusion​

The results of this study prescribe new prospects to understand the genetics basis of flowering time and sex determination in hemp. Molecular SNP markers and QTLs were identified for these quantitative traits. Genes involved in the photoperiod and temperature flowering pathways, such as genes involved in the perception and transduction of environmental signals (i.e., light), and genes involved in the autonomous and phytohormones flowering pathways, such as flowering transcription factors, were identified in QTLs for flowering time. About sex determination, genes involved in regulating the balance of phytohormones gibberellic acid (GA) and auxins were identified. The alleles with positive effects of these sex QTLs were found to promote monecious phenotypes. Finally, the SNP markers composing the QTLs can be used to develop new hemp cultivars with early or late flowering time behaviors and to select for monecious plants. SNP markers associated with sex determination will increase the stability of monoecy determination in monecious hemp cultivars.

 

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Hierarchical clustering of 40 genes involved in the isoprenoid pathway and 795 genes from other pathways. Clustering is depicted as a heatmap, in which red and green represent high and low expression values, respectively. Rows depict genes and columns depict hybridizations. Positions of the genes from the MEV pathway (m) and the plastoquinone and phytosterol pathways (+) are indicated in the left-hand column of the heatmap axis on the right side of the figure. Positions of the genes from the MEP pathway and the plastoquinone, carotenoid and chlorophyll pathways (+) are indicated in the right column of the axis.

Wille, A., Zimmermann, P., Vranová, E. et al. Sparse graphical Gaussian modeling of the isoprenoid gene network in Arabidopsis thaliana. Genome Biol 5, R92 (2004). https://doi.org/10.1186/gb-2004-5-11-r92

ORIGINAL RESEARCH article​

Front. Plant Sci., 30 June 2021
Sec. Plant Metabolism and Chemodiversity
Volume 12 - 2021 | https://doi.org/10.3389/fpls.2021.699530
This article is part of the Research TopicBehind the Smoke and Mirrors: Reflections on Improving Cannabis Production and Investigating Medical PotentialView all 16 articles

Identification of Chemotypic Markers in Three Chemotype Categories of Cannabis Using Secondary Metabolites Profiled in Inflorescences, Leaves, Stem Bark, and Roots​

 

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Cannabinoids and Terpenes: How Production of Photo-Protectants Can Be Manipulated to Enhance Cannabis sativa L. Phytochemistry.​

Desaulniers Brousseau V 1,
Wu BS 1,
MacPherson S 1,
Morello V 1,
Lefsrud M 1

Author information​

Frontiers in Plant Science, 31 May 2021, 12:620021
https://doi.org/10.3389/fpls.2021.620021

Genomic characterization of the complete terpene synthase gene family from Cannabis sativa

Terpenes are responsible for most or all of the odor and flavor properties of Cannabis sativa, and may also impact effects users experience either directly or indirectly. We report the diversity of terpene profiles across samples bound for the Washington dispensary market. The remarkable degree...

journals.plos.org

 

[acespicoli]

Terpene Groups as Strain Characteristics​

15 March 2023
Alexis St-Gelais, chimiste – Popularization & Plant profiles
The intensive breeding of cannabis produces strains that have different molecular signatures, and this is quite apparent within terpenes profile. These features can be useful to characterize a strain or extract, by putting forward what sets it apart from another variety. Based on our extensive experience with cannabis terpenes, let us have a look at some interesting molecular trends in the plant.

Chemotypes and Cannabis​

The production of molecules within the plant obeys a metabolic logic. A crude parallel can be made with the color of eyes in humans: depending on the genetic characteristics of an individual, our body will have the ability to produce (or not) pigments that will in turn determine the iris’ shade. The latter (although with multiple subtleties) can then be classified into a limited number of categories, like blue eyes. When studying plants, the concept of chemotype can be used to designate this phenomenon where molecules are expressed in some individuals and not (or less) in others. Polatoglu suggested the following definition for this concept: organisms categorized under same species […] having differences in quantity and quality of their component(s) in their whole chemical fingerprint that is related to genetic or genetic expression differences [1].
Within cannabis, cannabinoids tend to follow a chemotypical pattern, where one or two dominant cannabinoids are found but can vary from one strain to another. In The Handbook of Cannabis, de Meijer proposes a model with three genetic and one morphological turning points that can lead a given strain to express one of nine possible chemotypes (or even more, considering that one can have a mixed chemotype where two molecules are co-dominant, most typically THCA and CBDA) [2]. The model is summarized in figure 1 below, where the term “locus” refers to a zone in a chromosome of the cannabis plant where the genes encountered will influence the metabolic expression of cannabinoids.

Figure 1.

Olivetolic acid - Wikipedia

en.wikipedia.org

https://en.wikipedia.org/wiki/Divarinolic_acid

PY - 2020/02/24
T1 - Secondary Metabolites Profiled in Cannabis Inflorescences, Leaves, Stem Barks, and Roots for Medicinal Purposes
DO - 10.1038/s41598-020-60172-6
Figure 1. Genetic model proposed by de Meijer [2] (figure adapted by PhytoChemia) to explain cannabinoids chemotypes. A first locus controls the expression of enzymes which are necessary for the synthesis of metabolic precursors of the phenolic part of cannabinoids – if this locus is inactive, the plant will be short of raw metabolic material and no cannabinoids will be produced whatsoever. A second locus controls the length of the carbon chain attached to this phenolic backbone, defining a proportion between C3 and C5 phenolic acids (divarinolic acid vs olivetolic acid, the latter being the precursor of the familiar THCA and CBDA). A third locus works in a similar fashion to the A/B/AB/O blood types in humans (this parallel is ours, not de Meijer’s). If the locus is inactive (akin to type O), the metabolism stops at CBGA (or CBGVA); if the genetic information for type A is present, then THCA will be produced, whereas type B will lead to CBDA (and both types can be present, as with blood type AB, for a mixed chemotype). A fourth parameter can come into play and has to do with the morphology of the trichomes, which can in some case lead to the conversion of CBGA to CBCA and give more chemotypes.
As far as we are aware, a comprehensive model for cannabis terpenes has yet to be proposed (let us know if you know of one!). You can nevertheless see from the example of cannabinoids that genetic traits in a strain can define whether or not a given molecule will accumulate as an outcome of the plant’s metabolism – or in other terms, if the strain will pertain to a given chemotype.

Correlated Terpenes​

Very often, a given metabolic transformation will be driven by an enzyme, i.e., a protein that is able to facilitate a specific chemical transformation. Enzymes can be more or less selective in what type of molecules they can transform. When several molecules are similar in structure, they can sometimes all be transformed by the same enzyme, although not necessarily all with the same efficiency or speed. This implies that if the plant expresses a given enzyme thanks to its genetic traits, not only one, but several molecules can sometimes arise. In other cases, if one transformation of a key molecule is permitted upstream, several other transformations downstream become possible since the “raw material” has been made available. In any case, even without knowledge of the exact genetic and metabolic mechanisms at play, one can therefore examine if there are correlations between molecules, which would imply that they have a common origin. If that is the case, they should be considered together, because it is unlikely that only one of them will be found.
There are several such cases in cannabis terpenes. Here are quantitatively important groups to consider:

• • Pinenes correlate, with varying proportions of α- and β- isomers;
• • When limonene is abundant, a series of oxygenated monoterpenes tends to also increase in content;
• • A large proportion of terpinolene will be accompanied by the presence of several other monoterpenes;
• • β-caryophyllene and α-humulene are strongly correlated;
• • A group of eudesmane-type (or selinane) sesquiterpenes are closely tied. Those include α- and β-selinenes, a few selinadiene isomers and juniper camphor. They also correlate with spirovetiva-1(10),7(11)-diene and eremophila-1(10),7(11)-diene;
• • α- and δ-guaienes co-occur;
• • Germacrene B is always associated with γ-elemene by GC, since the latter is a thermal degradation product of germacrene B and therefore partly generated during analysis. (E)-α-bisabolene and α-bisabolol tend to somewhat correlate with germacrene B;
• • Finally, a cluster of sesquiterpenols including guaiol, eudesmols, bulnesol and cryptomeridiol are clearly tied together in terms of abundance.

Behavior of Terpenes Groups Across Strains​

As we have come to test thousands of samples, some trends have become apparent within or between the groups outlined above. Here are some recurring phenomenons we observe in our tests. Keep in mind that with intensive breeding, one can still stumble upon something unusual: these are trends, not absolute rules!

Monoterpenes​

The profile of terpenes is most of the time dominated by one or several monoterpenes amongst the following: myrcene, α-pinene*, limonene*, terpinolene*, (E)-β-ocimene and linalool – the latter two very seldom being the dominant compound. Remember that those marked by an asterisk come with peers. From the perspective of chemical trends, the cases of terpinolene and limonene are particularly interesting.
In the case of terpinolene, its presence seems to be a metabolic key for the expression of several other molecules. Whenever terpinolene is a dominant terpene, a diverse group of molecules that are usually found at best as traces become more salient. Some of them are represented in figure 2.

Figure 2. Compounds associated with terpinolene in cannabis. These molecules tend to be more abundant whenever a strain is rich in terpinolene, while being trace constituents or even entirely missing otherwise. In addition to those molecules, an unknown oxygenated monoterpene is also closely tied to terpinolene. It is eluted near terpinen-4-ol on a DB-5 column.
As for limonene, its concentration is correlated with that of camphene and several oxygenated monoterpenes including α-terpineol, endo-fenchol, and borneol, as well as pinene hydrates (figure 3). The latter are in fact relatively rare in the field of essential oils, with cannabis being one of the rare botanicals where they have some abundance alongside the rather uncommon African wild sage (or leleshwa), Tarchonanthus camphoratus.

Figure 3. Structures of molecules closely correlated to limonene abundance in cannabis.
Sesquiterpenes

β-Caryophyllene and α-Humulene​

These two sesquiterpenes (figure 4) can sometimes surpass monoterpenes in terms of concentrations in a strain. They are always expressed unless a strain or extract is almost devoid of terpenes. This is not so surprising, because these terpenes are amongst the most widely distributed in nature – relatively few essential oil bearing plants do not exhibit them. It will be extremely rare to see any cannabis where the sum of caryophyllene and humulene does not account for at least 1% (relative percentage) of total terpenes, and their distribution is relatively continuous across all their possible concentrations. As such, they do not really represent a chemotype, rather a continuum.

Figure 4. Structures of β-caryophyllene and α-humulene
Germacrene B
As mentioned earlier, germacrene B is not thermally stable (figure 5). Whenever it shows on a GC profile, it will inevitably be accompanied by γ-elemene, into which it partially rearranges within the heated injection port of the instrument [3]. These usually will not be featured in terpenes screens in most laboratories, because the germacrene B standard is hard to obtain – but it can nevertheless be a quantitatively important constituent of terpenes in some strains. We have seen the sum of germacrene B and γ-elemene reach well over 10 mg/g in some cases! And there are instances where germacrene B is almost missing entirely, with almost all possibilities in-between.
There is some degree of correlation between germacrene B and the pair of closely related compounds (E)-α-bisabolene and α-bisabolol, although in that case we sometimes observe examples where they are decoupled. The α-bisabolene/bisabolol pair exhibits some chemotypical behavior, where they are most of the time expressed in strains, but once in a while inhibited to very low levels.

Figure 5. Structures of germacrene B and fully or partially correlated compounds.
Guaienes
α-Guaiene and δ-guaiene (figure 6) are typically found in rose and patchouli essential oils, among others. In many cannabis strains, these sesquiterpenes will be rather faintly expressed, but in some cases, their expression is triggered to account for a few relative points of percentage of total terpenes. In all honesty, this is difficult to track from α-guaiene only, because it tends to coelute with another quantitatively abundant sesquiterpene of cannabis, trans-α-bergamotene, on many GC columns (DB-5 and DB-Wax included). δ-Guaiene is therefore the good cue to look at for this chemotype. There are exceptions, but together the guaienes will typically either account for under 0.5 mg/g of terpenes or be found in the 1-3 mg/g bracket, which would suggest that there is a genetic trait that either allows or inhibits their production. α-Guaiene can oxidize over time into a potent odorant compound, rotundone [4] – it is probably too faint to be monitored directly in cannabis but could contribute to the aroma of some strains.

Figure 6. Structures of guaienes.
Eudesmanes (Selinanes)
This is one group of sesquiterpenes (figure 7) that you do not want to miss if you want an accurate account of the terpenes content of a strain. Selinadienes are, in many strains, amongst the most abundant terpenes overall, sometimes contributing well over 10 mg/g in total. As far as we are aware, cannabis is also the botanical where these molecules are the most prominent. The fact that our screen takes them into account whereas many laboratories disregard them goes a long way to explain the difference in “total terpenes” reported – and keep in mind the concept of total terpenes requires precautions.

Figure 7. Structures of the main eudesmane-type sesquiterpenes found in cannabis, and the correlated spirovetiva-1(10),7(11)-diene and eremophila-1(10),7(11)-diene. The group also includes selina-4,7(11)-diene.
There appears to be chemotypes with regards to eudesmanes, too. In a few strains, they are almost absent, implying that the absence of a given gene inhibits their metabolism.

Bulnesol/guaiol/eudesmols Sesquiterpenols​

One last interesting group comprises several molecules that are closely correlated (figure 8), including bulnesol, guaiol and several eudesmol isomers. Except for cryptomeridiol, they are all featured roughly in the same amounts, and they follow a presence/absence chemotypical pattern. Some strains clearly express the group, whereas the molecules are found in traces only in other cases. In our experience, this is one of the most variable metabolic traits between strains, along with the dominant monoterpenes.

Figure 8. Compounds correlated in a cluster of sesquiterpenols found in cannabis, with none of them clearly dominating the rest.
Bottom Line
The proportions between terpenes can be useful tools to describe strains. Our full terpenes service comes with a short conclusion that will highlight a few trends regarding the groups discussed above, and we keep thinking of good ways to capture the terpenes chemotypes in cannabis to better convey this information to our customers in the future.

References​

[1] Polatoglu, K. “Chemotypes”– A Fact That Should Not Be Ignored in Natural Product Studies. Nat. Prod. J. 2013, 3 (1), 10–14. https://doi.org/10.2174/2210315511303010004.
[2] de Meijer, E. The Chemical Phenotypes (Chemotypes) of Cannabis. In The Handbook of Cannabis; Pertwee, R. G., Ed.; Oxford University Press: Oxford, 2014; pp 89–110.
[3] Venditti, A. What Is and What Should Never Be: Artifacts, Improbable Phytochemicals, Contaminants and Natural Products. Nat. Prod. Res. 2020, 34 (7), 1014–1031. https://doi.org/10.1080/14786419.2018.1543674.
[4] Huang, A.-C.; Burrett, S.; Sefton, M. A.; Taylor, D. K. Production of the Pepper Aroma Compound, (−)-Rotundone, by Aerial Oxidation of α-Guaiene. J. Agric. Food Chem. 2014, 62 (44), 10809–10815. https://doi.org/10.1021/jf504693e.

Terpene Groups as Strain Characteristics | Phytochemia

phytochemia.com

https://en.wikipedia.org/wiki/Tetrahydrocannabivarin#Biosynthesis​

Biosynthesis​

Unlike THC, cannabidiol (CBD), and cannabichromene (CBC), THCV doesn't begin as cannabigerolic acid (CBGA). Instead of combining with olivetolic acid to create CBGA, geranyl pyrophosphate joins with divarinolic acid, which has two fewer carbon atoms. The result is cannabigerovarin acid (CBGVA). Once CBGVA is created, the process continues exactly the same as it would for THC. CBGVA is broken down to tetrahydrocannabivarin carboxylic acid (THCVA) by the enzyme THCV synthase. At that point, THCVA can be decarboxylated with heat or UV light to create THCV.[12]