[Sam_Skunkman]

I have seen them, both that will not show intersex and plants and /or that will make male flowers but no viable pollen. I do not consider the later pure female. As they may yield progeny that makes fertile intersex flowers.
-SamS

[Illuminate]

I think under high selective pressure with large plant count, it's easier to find true females. Over the years I have deliberately messed with the lights and nutrition schedule during my search for mums, and found at least 10 different plants that did not produce pollen or sacs under those conditions. Probably about 5% or less of all the plants I've ever stressed were those girls, Exodus cheese aka skunk#1 was one.

[Sam_Skunkman]

One more, and this one is really good:

https://onlinelibrary.wiley.com/doi/1...nph.13562/full



Gene duplication and divergence affecting drug content in Cannabis sativa
New Phytologist 17 July 2015
George D. Weiblen, Jonathan P. Wenger, Kathleen J. Craft, Mahmoud A. ElSohly,
Zlatko Mehmedic, Erin L. Treiber, M. David Marks

Summary

Cannabis sativa is an economically important source of durable fibers, nutritious seeds, and psychoactive drugs but few economic plants are so poorly understood genetically.

Marijuana and hemp were crossed to evaluate competing models of cannabinoid inheritance and to explain the predominance of tetrahydrocannabinolic acid (THCA) in marijuana compared with cannabidiolic acid (CBDA) in hemp. Individuals in the resulting F2 population were assessed for differential expression of cannabinoid synthase genes and were used in linkage mapping. Genetic markers associated with divergent cannabinoid phenotypes were identified.

Although phenotypic segregation and a major quantitative trait locus (QTL) for the THCA/CBDA ratio were consistent with a simple model of codominant alleles at a single locus, the diversity of THCA and CBDA synthase sequences observed in the mapping population, the position of enzyme coding loci on the map, and patterns of expression suggest multiple linked loci. Phylogenetic analysis further suggests a history of duplication and divergence affecting drug content.

Marijuana is distinguished from hemp by a nonfunctional CBDA synthase that appears to have been positively selected to enhance psychoactivity. An unlinked QTL for cannabinoid quantity may also have played a role in the recent escalation of drug potency.

[Sam_Skunkman]

A new review and an older review but great.
Old:
https://www.researchgate.net/publicat...n_cannabinoids

A historical overview of chemical research on cannabinoids
Chemistry and Physics of Lipids
108 (2000) 1–13
Raphael Mechoulam , Lumı´r Hanusˇ
Department of Medicinal Chemistry and Natural Products, Hebrew Uni6ersity of Jerusalem, Medical Faculty, Ein Kerem Campus,
91120 Jerusalem, Israel

Abstract
The chemical research on the plant cannabinoids and their derivatives over two centuries is concisely reviewed. The tortuous path leading to the discovery of the endogenous cannabinoids is described. Future directions, which will probably be followed are delineated.

-----------------------
NEW:

https://www.researchgate.net/publicat...ids_and_beyond

Early phytocannabinoid chemistry to endocannabinoids and beyond
Nature Reviews / Neuroscience Vol 15 Nov 1014 Pg 757-764 Perspectives
Raphael Mechoulam, Lumír O. Hanuš, Roger Pertwee and
Allyn C. Howlett
Abstract
Isolation and structure elucidation of most of the major cannabinoid constituents — including Δ9-tetrahydrocannabinol (Δ9-THC), which is the principal psychoactive molecule in Cannabis sativa — was achieved in the 1960s and 1970s. It was followed by the identification of two cannabinoid receptors in the 1980s and the early 1990s and by the identification of the endocannabinoids shortly thereafter. There have since been considerable advances in our understanding of the endocannabinoid system and its function in the brain, which reveal potential therapeutic targets for a wide range of brain disorders.

[Sativied]

Originally Posted by Sam_Skunkman

One more:

https://onlinelibrary.wiley.com/doi/1...nph.13562/full

Gene duplication and divergence affecting drug content in Cannabis sativa

That should be mandatory reading for any cannabis breeder, especially for those underestimating or even denying the importance of mendel's work. Read at least the Quality vs Quantity and Cannabinoid synthase evolution sections.

The former shows nicely how important it is to distinguish between qualitative traits and quantitative traits, which directly affects a breeding program and required plant count. Only need a few plants and generations to breed a trait into another variety, getting it in the highest amounts and uniform is much harder and requires more plants and more generations.

[Sam_Skunkman]

Not new, not Cannabis specific, but maybe interesting?

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3474957/

Effect of Soil Nutrient on Production and Diversity of Volatile Terpenoids from Plants
E Ormeño* and C Fernandez

Curr Bioact Compd. 2012 Jan; 8(1): 71–79.

Abstract
Terpenoid production (emission and storage) within foliage plays direct and indirect defensive and protective functions for the plant, mediates complex trophic relationships and controls the oxidation capacity of the atmosphere. Both biotic and abiotic conditions alter terpenoid production, with herbivory, light and temperature effects being reasonably well understood. In this manuscript, the state of the science about nutrient effect on terpenoid production is reviewed. The focus is on isoprene emissions and mono- and sesquiterpenoid emissions and concentrations according to fertilizing treatments and their potential interaction with other environmental factors. Ecological, physiological, biochemical and biophysical hypothesis formulated over research investigations are exposed and several points are highlighted as future research perspectives which could help to elucidate the apparent contrasting results.

[Sam_Skunkman]

https://www.ncbi.nlm.nih.gov/pubmed/26577065


J Psychopharmacol. 2015 Nov 17. pii: 0269881115615104. [Epub ahead of print]
The effect of five day dosing with THCV on THC-induced cognitive, psychological and physiological effects in healthy male human volunteers: A placebo-controlled, double-blind, crossover pilot trial.
Englund A1, Atakan Z2, Kralj A2, Tunstall N2, Murray R2, Morrison P2.

Abstract
RATIONALE:
Cannabis is mostly grown under illegal and unregulated circumstances, which seems to favour a product increasingly high in its main cannabinoid ∆-9-tetrahydrocannabinol (THC). ∆-9-tetrahydrocannabivarin (THCV) is a relatively untested cannabinoid which is said to be a cannabinoid receptor neutral antagonist, and may inhibit the effects of THC.
OBJECTIVES:
To explore the safety and tolerability of repeated THCV administration and its effects on symptoms normally induced by THC in a sample of healthy volunteers.
METHODS:
Ten male cannabis users (<25 use occasions) were recruited for this within-subjects, placebo-controlled, double-blind, cross-over pilot study. 10mg oral pure THCV or placebo were administered daily for five days, followed by 1mg intravenous THC on the fifth day.
RESULTS:
THCV was well tolerated and subjectively indistinguishable from placebo. THC did not significantly increase psychotic symptoms, paranoia or impair short-term memory, while still producing significant intoxicating effects. Delayed verbal recall was impaired by THC and only occurred under placebo condition (Z=-2.201, p=0.028), suggesting a protective effect of THCV. THCV also inhibited THC-induced increased heart rate (Z=-2.193, p=0.028). Nine out of ten participants reported THC under THCV condition (compared to placebo) to be subjectively weaker or less intense (χ2=6.4, p=0.011). THCV in combination with THC significantly increased memory intrusions (Z=-2.155, p=0.031).
CONCLUSION:
In this first study of THC and THCV, THCV inhibited some of the well-known effects of THC, while potentiating others. These findings need to be interpreted with caution due to a small sample size and lack of THC-induced psychotomimetic and memory-impairing effect, probably owing to the choice of dose.



FYI, I did THCV/THC trials 15 years ago, unpublished, but we found much the same, THCV is not for recreational users unless they like their THC tuned down. THCV delays THC onset, reduces peak experiences, and maybe lengthens the reduced effects.
-SamS

[Sam_Skunkman]

Not an article but interesting.
-SamS


https://cannabis-med.org/members/wp-c...11/Pertwee.pdf

New potential therapeutic applications for certain phytocannabinoids revealed by pharmacological discoveries
Roger Pertwee

[MJtheIndicator]

Originally Posted by Sam_Skunkman

FYI, I did THCV/THC trials 15 years ago, unpublished, but we found much the same, THCV is not for recreational users unless they like their THC tuned down. THCV delays THC onset, reduces peak experiences, and maybe lengthens the reduced effects.
-SamS

Been interested in metabolic trials as regards these two. Or rather if THCV is a green light to amplify metabolites. The drug affect might still be there in its typical role, but anabolism is over-compensating pushing enzymatic process to the fore. Current studies make it sound like one is still just as high, with greater metabolic threshold. One is not hypothetically "less high", but working harder. Question being which wears off quicker the homologue or THC? Maybe compartmentalizing studies to anabolic vs. psychoactive is a means to circumvent scientific preoccupation with attenuates.

[Josch Edgington]

Sam where is the old school skunk I smelt in the closet in the seventies and eighties?