[Sam_Skunkman]

One more new one:
I find interesting as CBD has been reported to not bind to the CB1 yet it does modulate THC, this is how.
-SamS

https://www.ncbi.nlm.nih.gov/pubmed/26218440

Br J Pharmacol. 2015 Jul 27.
Cannabidiol is a negative allosteric modulator of the type 1 cannabinoid receptor.

BACKGROUND AND PURPOSE:
Cannabidiol has been reported to act as an antagonist of cannabinoid agonists at type 1 cannabinoid receptors (CB1 ). We hypothesized that cannabidiol can inhibit cannabinoid agonist activity through negative allosteric modulation of CB1 .

[R043]

I first would like to thank the OP for this initiative which I found quite interesting and informative.

Secondly regarding the view that some shared, that the OP should have take the time to vulgarize the different study seems to me as lacking perspective.

I personally (and would think others are sharing my point of view) would rather have access to the material the OP offered than nothing at all and if he does not have the time to proceed with a full explanation of each article as he stated, it seems to me it would makes more sens to thank him instead of implying that it would have been his responsibility to do so.

Finally, a bit earlier today while browsing the interwebs I have stumble upon an interesting abstract I collected and after reading this whole thread, though it might be appropriate to share it.

My apologies if most of you are already aware of this study of if it seems unreliable as I do not feel competent enough to judge of this by myself.


Planta Med. 2010 Nov;76(16):1938-9. doi: 10.1055/s-0030-1249978. Epub 2010 Jun 8.

Genetic identification of female Cannabis sativa plants at early developmental stage.

Techen N1, Chandra S, Lata H, Elsohly MA, Khan IA.
Author information

Abstract

Sequence-characterized amplified region (SCAR) markers were used to identify female plants at an early developmental stage in four different varieties of Cannabis sativa. Using the cetyl trimethylammonium bromide (CTAB) method, DNA was isolated from two-week-old plants of three drug-type varieties (Terbag W1, Terbag K2, and Terbag MX) and one fiber-type variety (Terbag Fedora A7) of C. sativa grown under controlled environmental conditions through seeds. Attempts to use MADC2 (male-associated DNA from Cannabis sativa) primers as a marker to identify the sex of Cannabis sativa plants were successful. Amplification of genomic DNA using MADC2-F and MADC2-R primers produced two distinct fragments, one with a size of approximately 450 bp for female plants and one for male plants with a size of approximately 300 bp. After harvesting the tissues for DNA extraction, plants were subjected to a flowering photoperiod (i.e., 12-h light cycle), and the appearance of flowers was compared with the DNA analysis. The results of the molecular analysis were found to be concordant with the appearance of male or female flowers. The results of this study represent a quick and reliable technique for the identification of sex in Cannabis plants using SCAR markers at a very early developmental stage.

© Georg Thieme Verlag KG Stuttgart · New York.

PMID:20533168[PubMed - indexed for MEDLINE]

[Sam_Skunkman]

https://www.esciencecentral.org/journ....php?aid=57624

https://dx.doi.org/10.4172/2329-6836.1000181

Open access full text!!

Natural Products Chemistry & Research
Cannabinoids and Terpenes as Chemotaxonomic Markers in Cannabis
Elzinga S, Fischedick J, Podkolinski R, and Raber J

Abstract
In this paper, we present principal component analysis (PCA) results from a dataset containing 494 cannabis
flower samples and 170 concentrate samples analyzed for 31 compounds. A continuum of chemical composition
amongst cannabis strains was found instead of distinct chemotypes. Our data shows that some strains are much
more reproducible in chemical composition than others. Strains labeled as indica were compared with those labeled
as sativa and no evidence was found that these two cultivars are distinctly different chemotypes. PCA of “OG” and
“Kush” type strains found that “OG” strains have relatively higher levels of α-terpineol, fenchol, limonene, camphene, terpinolene and linalool where “Kush” samples are characterized mainly by the compounds trans-ocimene, guaiol, β-eudesmol, myrcene and α-pinene. The composition of concentrates and flowers were compared as well. Although the absolute concentration of compounds in concentrates is much higher, the relative composition of compounds between flowers and concentrates is similar.
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https://www.docdroid.net/teh6qCm/1010...157-3.pdf.html
You can download the pdf here, just push the download button at the site

https://link.springer.com/article/10....229-015-9157-3

The Botanical Review
August 2015
Date: 19 Aug 2015
Evolution and Classification of Cannabis sativa (Marijuana, Hemp) in Relation to Human Utilization
Ernest Small

Abstract
Cannabis sativa has been employed for thousands of years, primarily as a source of a stem fiber (both the plant and the fiber termed “hemp”) and a resinous intoxicant (the plant and its drug preparations commonly termed “marijuana”). Studies of relationships among various groups of domesticated forms of the species and wild-growing plants have led to conflicting evolutionary interpretations and different classifications, including splitting C. sativa into several alleged species. This review examines the evolving ways Cannabis has been used from ancient times to the present, and how human selection has altered the morphology, chemistry, distribution and ecology of domesticated forms by comparison with related wild plants. Special attention is given to classification, since this has been extremely contentious, and is a key to understanding, exploiting and controlling the plant. Differences that have been used to recognize cultivated groups within Cannabis are the results of disruptive selection for characteristics selected by humans. Wild-growing plants, insofar as has been determined, are either escapes from domesticated forms or the results of thousands of years of widespread genetic exchange with domesticated plants, making it impossible to determine if unaltered primeval or ancestral populations still exist. The conflicting approaches to classifying and naming plants with such interacting domesticated and wild forms are examined. It is recommended that Cannabis sativa be recognized as a single species, within which there is a narcotic subspecies with both domesticated and ruderal varieties, and similarly a non-narcotic subspecies with both domesticated and ruderal varieties. An alternative approach consistent with the international code of nomenclature for cultivated plants is proposed, recognizing six groups: two composed of essentially non-narcotic fiber and oilseed cultivars as well as an additional group composed of their hybrids; and two composed of narcotic strains as well as an additional group composed of their hybrids.

[Sam_Skunkman]

Bump

[MrBelvedere]

Thx, this has a lot of good info on trying to understand whorling...

https://www.ncbi.nlm.nih.gov/pmc/arti...report=classic

A Dynamical Phyllotaxis Model to Determine Floral Organ Number

Abstract
How organisms determine particular organ numbers is a fundamental key to the development of precise body structures; however, the developmental mechanisms underlying organ-number determination are unclear. In many eudicot plants, the primordia of sepals and petals (the floral organs) first arise sequentially at the edge of a circular, undifferentiated region called the floral meristem, and later transition into a concentric arrangement called a whorl, which includes four or five organs. The properties controlling the transition to whorls comprising particular numbers of organs is little explored. We propose a development-based model of floral organ-number determination, improving upon earlier models of plant phyllotaxis that assumed two developmental processes: the sequential initiation of primordia in the least crowded space around the meristem and the constant growth of the tip of the stem. By introducing mutual repulsion among primordia into the growth process, we numerically and analytically show that the whorled arrangement emerges spontaneously from the sequential initiation of primordia. Moreover, by allowing the strength of the inhibition exerted by each primordium to decrease as the primordium ages, we show that pentamerous whorls, in which the angular and radial positions of the primordia are consistent with those observed in sepal and petal primordia in Silene coeli-rosa, Caryophyllaceae, become the dominant arrangement. The organ number within the outmost whorl, corresponding to the sepals, takes a value of four or five in a much wider parameter space than that in which it takes a value of six or seven. These results suggest that mutual repulsion among primordia during growth and a temporal decrease in the strength of the inhibition during initiation are required for the development of the tetramerous and pentamerous whorls common in eudicots.

[Sam_Skunkman]

One more:

https://www.plosone.org/article/fetch...esentation=PDF

The Genetic Structure of Marijuana and Hemp
Jason Sawler, Jake M. Stout, Kyle M. Gardner, Darryl Hudson, John Vidmar, Laura Butler, Jonathan E. Page, Sean Myles PLOS x
Published: August 26, 2015DOI: 10.1371/journal.pone.0133292

Despite its cultivation as a source of food, fibre and medicine, and its global status as the most used illicit drug, the genus Cannabis has an inconclusive taxonomic organization and evolutionary history. Drug types of Cannabis (marijuana), which contain high amounts of the psychoactive cannabinoid Δ9-tetrahydrocannabinol (THC), are used for medical purposes and as a recreational drug. Hemp types are grown for the production of seed and fibre, and contain low amounts of THC. Two species or gene pools (C. sativa and C. indica) are widely used in describing the pedigree or appearance of cultivated Cannabis plants. Using 14,031 single-nucleotide polymorphisms (SNPs) genotyped in 81 marijuana and 43 hemp samples, we show that marijuana and hemp are significantly differentiated at a genome-wide level, demonstrating that the distinction between these populations is not limited to genes underlying THC production. We find a moderate correlation between the genetic structure of marijuana strains and their reported C. sativa and C. indica ancestry and show that marijuana strain names often do not reflect a meaningful genetic identity. We also provide evidence that hemp is genetically more similar to C. indica type marijuana than to C. sativa strains.

[oldchuck]

Man, this taxonomy tangle is fascinating but it's also nuts:

"We also provide evidence that hemp is genetically more similar to C. indica type marijuana than to C. sativa strains."

Linnaeus originally defined Cannabis Sativa as hemp. Now these guys are saying hemp is genetically more like Cannabis Indica which Lamarck thought came from India but now is said to be actually Cannabis Afganica.

Clearly, Cannabis is a global genetic stewpot but the fact remains that Cannabis from everywhere is willing and able to breed freely with Cannabis from everywhere else. That makes it a single species in my humble opinion.

[Only Ornamental]

Originally Posted by oldchuck

...
Clearly, Cannabis is a global genetic stewpot but the fact remains that Cannabis from everywhere is willing and able to breed freely with Cannabis from everywhere else. That makes it a single species in my humble opinion.

Hi oldchuck
Look at cacti and orchids, many breed freely with each other (obviously cactus with cactus and orchid with orchid). Still, they are only loosely related and comprise very different genera.

[Donn]

Sure, and orchid taxonomy too - not something I know a lot about, but happened this week to be reading about Brazilian Laelia species, which were then reclassified as Sophronitis, but that only lasted a few years and then they got shuffled over to Cattleya. Lots of very popular orchids are Laeliocattleya hybrids - but maybe with parents that are now both Cattleya? so in principle that needs to be straightened out too. And likewise the Brassolaeliocattleya hybrids are usually a parent that was removed from Brassavola some time back, and now they're really Ryncholaeliocattleya.

It's wonderful that they're able to make these giant strides with their taxonomy, but it doesn't really serve the trade very well, I'm guessing. The same could be said for the sativa/indica/afghanica thing. Sometimes I think there ought to be some stiff fee attached to changing a botanical name that's in wide use.

[MrBelvedere]

Plant taxonomy is just us humans making a lame attempt at trying to assign words to differentiate plants, nothing more, nothing less.