The characterization of key physiological traits of medicinal cannabis (Cannabis sativa L.) as a tool for precision breeding

BACKGROUND

For millennia, drug-type cannabis strains were extensively used for various medicinal, ritual, and inebriant applications. However, cannabis prohibition during the last century led to cultivation and breeding activities being conducted under clandestine conditions, while scientific development of the crop ceased. Recently, the potential of medicinal cannabis has been reacknowledged and the now expanding industry requires optimal and scientifically characterized varieties. However, scientific knowledge that can propel this advancement is sorely lacking. To address this issue, the current study aims to provide a better understanding of key physiological and phenological traits that can facilitate the breeding of advanced cultivars.

RESULTS

A diverse population of 121 genotypes of high-THC or balanced THC-CBD ratio was cultivated under a controlled environment facility and 13 plant parameters were measured. No physiological association across genotypes attributed to the same vernacular classification was observed. Floral bud dry weight was found to be positively associated with plant height and stem diameter but not with days to maturation. Furthermore, the heritability of both plant height and days to maturation was relatively high, but for plant height it decreased during the vegetative growth phase. To advance breeding efficacy, a prediction equation for forecasting floral bud dry weight was generated, driven by parameters that can be detected during the vegetative growth phase solely.

CONCLUSIONS

Our findings suggest that selection for taller and fast-growing genotypes is likely to lead to an increase in floral bud productivity. It was also found that the final plant height and stem diameter are determined by 5 independent factors that can be used to maximize productivity through cultivation adjustments. The proposed prediction equation can facilitate the selection of prolific genotypes without the completion of a full cultivation cycle. Future studies that will associate genome-wide variation with plants morphological traits and cannabinoid profile will enable precise and accelerated breeding through genomic selection approaches.

Biotechnological Approaches on Two High CBD and CBG Cannabis sativa L. (Cannabaceae) Varieties: In Vitro Regeneration and Phytochemical Consistency Evaluation of Micropropagated Plants Using Quantitative 1H-NMR

High cannabidiol (CBD) and cannabigerol (CBG) varieties of Cannabis sativa L., a species with medicinal properties, were regenerated in vitro. Explants of nodal segments including healthy axillary bud, after sterilization, were placed in Murashige-Skoog (MS) culture medium. The shoots formed after 30 days were subcultured in full- or half-strength MS medium supplemented with several concentrations of 6-benzyl-amino-purine (BA) or thidiazuron (TDZ). The highest average number and length of shoots was achieved when both full and half-strength MS media were supplemented with 4.0 μM BA. The presence of 4.0 μM TDZ showed also comparable results. BA and TDZ at concentrations of 4.0, 8.0 μM and 2.0, 4.0 μM respectively, displayed the maximum shooting frequency. The new shoots were transferred on the same media and were either self-rooted or after being enhanced with different concentrations of indole-3-butyric acid (IBA) or α-naphthalene acetic acid (NAA). Presence of 2.0 or 4.0 μM IBA or 4.0 μM NAA resulted to the optimum rooting rates. The maximum average number and length of roots per shoot was observed when the culture media was supplemented with 4.0 μM IBA or NAA. Approximately 92% of the plantlets were successfully established and acclimatized in field. The consistency of the chemical profile of the acclimatized in vitro propagated clones was assessed using quantitative ¹H-NMR high throughput screening. In each variety, analysis of the micropropagated plant in comparison with the mother plant showed no statistically significant differences (p ≤ 0.05) in CBD+ cannabidiolic acid (CBDA) and CBG+ cannabigerolic acid (CBGA) content respectively, thus indicating stability of their chemical profile.

[Cannabis: Similarities and differences with tobacco]

Nicotine is the specific psychoactive substance of tobacco while tetrahydrocannabinol (THC) is the specific component of cannabis. The inhalation technique of cannabis is different from that of tobacco smoking: the volume of puffs is larger, inhalation is deeper, and pulmonary retention time is longer. Cannabis addiction is difficult to evaluate, both products often being smoked concomitantly. The principle physical side effects of cannabis affect organs and functions in a similar way to tobacco: pulmonary, cardiovascular, endocrine and stomatological. Gastrointestinal complications such as cannabinoid hyperemesis are specific to cannabis. Some psychological effects of THC may be acute (altered time and space perception, sensory disability, decreased vigilance, mood and dissociative disorders, hallucinations and delirium, impaired learning and memory, impaired cognitive and motor performance, panic attacks and anxiety) or chronic (lack of motivation, disorganisation of thoughts, increase in frequency and severity of schizophrenic crises). Cannabis can also be implicated in traffic and workplace accidents. Synthetic cannabinoids have increased psychotropic and somatic effects due to a greater affinity for brain cannabinoid receptors.

Photochemical efficiency is negatively correlated with the Δ9- tetrahydrocannabinol content in Cannabis sativa L

Cannabis sativa L is an important plant, which is a source of durable fibers, nutritious seeds, and medicinally important phytocannabinoids including Δ⁹-tetrahydrocannabinol (THC) and cannabidiol (CBD). Light has shown to be a key modulator of biomass and cannabinoid yield suggesting responsive photochemical machinery. The present study was envisaged to understand the effect of the increasing levels of metabolic THC on the photochemical efficiency in Cannabis. The chlorophyll a fluorescence kinetics, photosynthetic pigments and immuno-detection of the photosynthetic machinery was analyzed on seven accessions from different environments, in conjunction with the cannabinoid content. All the accessions were clearly divided into three groups based on their relative content of CBD and THC. Group I with (CBD/THC > 1) had a clear advantage in terms of the damage to the D1, RbCL and Lhc1 protein holo-complex. Performance indicators of photochemistry based on the OJIP kinetics suggested a stoichiometrically negative correlation with the THC content. Zeaxanthin-dependent quenching is primarily responsible for lower NPQ in Group III with high THC content (THC > 6%). The THC treatment on Arabidopsis thaliana also suggested dose-dependent decrease in the photochemical efficiency suggesting the exclusivity of THC in causing the response. This resulted in the damage of photosynthetic machinery and the generation of free radicals, thereby compromising the yield. The study also opens a new screening method for Cannabis, based on cannabinoid content.

Phytocannabinoids: Useful Drugs for the Treatment of Obesity? Special Focus on Cannabidiol

Currently, an increasing number of diseases related to insulin resistance and obesity is an alarming problem worldwide. It is well-known that the above states can lead to the development of type 2 diabetes, hypertension, and cardiovascular diseases. An excessive amount of triacylglycerols (TAGs) in a diet also evokes adipocyte hyperplasia and subsequent accumulation of lipids in peripheral organs (liver, cardiac muscle). Therefore, new therapeutic methods are constantly sought for the prevention, treatment and alleviation of symptoms of the above mentioned diseases. Currently, much attention is paid to Cannabis derivatives-phytocannabinoids, which interact with the endocannabinoid system (ECS) constituents. Δ⁹-tetrahydrocannabinol (Δ⁹-THC) and cannabidiol (CBD) are the most abundant compounds of Cannabis plants and their therapeutic application has been suggested. CBD is considered as a potential therapeutic agent due to its anti-inflammatory, anti-oxidant, anti-tumor, neuroprotective, and potential anti-obesity properties. Therefore, in this review, we especially highlight pharmacological properties of CBD as well as its impact on obesity in different tissues.

Has the "M" word been framed? Marijuana, cannabis, and public opinion

Over the past two decades, a growing cadre of US states has legalized the drug commonly known as "marijuana." But even as more states legalize the drug, proponents of reform have begun to shun the term "marijuana" in favor of the term "cannabis." Arguing that the "M" word has been tainted and may thus dampen public support for legalization, policy advocates have championed "cannabis" as an alternative and more neutral name for the drug. Importantly, however, no one has tested whether calling the drug "cannabis" as opposed to "marijuana" actually has any effect on public opinion. Using an original survey experiment, we examine whether framing the drug as "marijuana" as opposed to "cannabis" shapes public attitudes across a range of related topics: support for legalization of the drug, moral acceptance of its use, tolerance of activities involving the drug, perceptions of the drug's harms, and stereotypes of its users. Throughout each of our tests, we find no evidence to suggest that the public distinguishes between the terms "marijuana" and "cannabis." We conclude with implications of our findings for debates over marijuana/cannabis policy and for framing in policy discourse more generally.

Enhanced tolerance of industrial hemp (Cannabis sativa L.) plants on abandoned mine land soil leads to overexpression of cannabinoids

Industrial activities have a detrimental impact on the environment and health when high concentrations of pollutants are released. Phytoremediation is a natural method of utilizing plants to remove contaminants from the soil. The goal of this study was to investigate the ability of Cannabis sativa L. to sustainably grow and remediate abandoned coal mine land soils in Pennsylvania. In this study, six different varieties of industrial hemp (Fedora 17, Felina 32, Ferimon, Futura 75, Santhica 27, and USO 31) were grown on two different contaminated soil types and two commercial soils (Miracle-Gro Potting Mix and PRO-MIX HP Mycorrhizae High Porosity Grower Mix). Plants growing in all soil types were exposed to two environmental conditions (outside and in the greenhouse). Seed germination response and plant height indicated no significant differences among all hemp varieties grown in different soils, however on an average, the height of the plants grown in the greenhouse exceeded that of the plants grown outdoors. In addition, heavy metal analysis of Arsenic, Lead, Nickel, Mercury, and Cadmium was performed. The concentration of Nickel was 2.54 times greater in the leaves of hemp grown in mine land soil outdoors when compared to greenhouse conditions. No differences were found between expression of heavy metal transporter genes. Secondary metabolite analysis of floral buds from hemp grown in mine land soil displayed a significant increase in the total Cannabidiol content (2.16%, 2.58%) when compared to Miracle-Gro control soil (1.08%, 1.6%) for outdoors and in the greenhouse, respectively. Molecular analysis using qRT-PCR indicated an 18-fold increase in the expression of the cannabidiolic acid synthase gene in plants grown on mine land soil. The data indicates a high tolerance to heavy metals as indicated from the physiological and metabolites analysis.

Phenotypic plasticity influences the success of clonal propagation in industrial pharmaceutical Cannabis sativa

The burgeoning cannabis market requires evidence-based science such that farmers can quickly and efficiently generate new plants. In part, horticultural operations are limited by the success of cloning procedures. Here, we measured the role of environmental conditions and cultivar identity on the success of generating long branch material with many meristems in planting stock (mothers) and in rooting success of stem-derived clones. To evaluate the influence of lighting treatments on the optimal production of branching mothers, four lighting conditions (Fluorescent High Output T5s [T5], Metal halide lamps [MH], Plasma lamps [PL], or Metal halide lamps augmented with far red LED lights [MH+FR]) were applied to two cultivars of container grown plants (Cannabis sativa L. 'Bubba Kush', 'Ghost Train Haze') grown in peat-based organic substrates in mylar grow tents. To evaluate the influence of lighting, cutting tool (secateurs or scalpels), and stem wounding (present/absent) on optimal rooting of stems, three lighting conditions (Fluorescent T8s, T5, PL) were applied to three cultivars of peat pellet grown plants (C. sativa L. 'Bubba Kush', 'Ghost Train Haze', 'Headband'). Mothers grown under T5 and MH (vs MH+FR) produced ~30% more meristems. However, growing mothers under MH+FR were 19% taller than mothers under T5, with ~25% longer internodes on dominant stems than plants under any other lighting condition. Canopies were denser under T5 because petiole length was ~30% shorter under T5 and fan leaves were longer and narrower under MH+FR and MH+FR and PL, respectively, than under other lighting conditions. Cultivar Ghost Train Haze stems rooted most frequently and most quickly. Wounded stems were 162% more likely to root than unwounded stems and rooted 1.5 days earlier. Our results will guide producers attempting to maximize the rate of clone production in licensed facilities; although results may differ among cultivars, where cultivars differed in their average phenotype as mother plants, and their propensity to root from cuttings, and the speed with which they produced those roots.

Women's perspectives about cannabis use during pregnancy and the postpartum period: An integrative review

Cannabis is the most commonly used illicit drug among general and pregnant populations. Despite recommendations to abstain from cannabis use, its use is increasing during the perinatal period. In this integrative review, we aim to understand women's perspectives about the health aspects of perinatal cannabis use. The following databases were searched: MEDLINE, PsycInfo, EMBASE, and CINAHL. We included quantitative and qualitative studies with a primary focus on perinatal cannabis use. The methodological quality of the included studies was appraised using appropriate checklists. Extracted data were integrated into a single data matrix and iteratively compared across studies to summarize and synthesize the data. Full text of 33 citations was retrieved and reviewed of which 6 studies met the inclusion criteria. Women who continued to use cannabis during pregnancy often perceived no general or pregnancy-specific risk compared to nonusers. The uncertainty regarding adverse perinatal consequences, its perceived therapeutic effects, and lower costs of cannabis compared to that of cigarettes contributed to cannabis use. A lack of communication with health care providers regarding the health aspects of cannabis was evident. Women perceived this lack of counseling as an indication that adverse outcomes associated with cannabis use are not significant. Women's perceptions of health risks associated with cannabis use are important factors in the decision-making process regarding use or cessation, particularly as legal concerns are fading away. A discussion about health concerns surrounding cannabis use may influence women's perceptions of risk and help them to make informed choices.

High times for cannabis: Epigenetic imprint and its legacy on brain and behavior

Extensive debates continue regarding marijuana (Cannabis spp), the most commonly used illicit substance in many countries worldwide. There has been an exponential increase of cannabis studies over the past two decades but the drug's long-term effects still lack in-depth scientific data. The epigenome is a critical molecular machinery with the capacity to maintain persistent alterations of gene expression and behaviors induced by cannabinoids that have been observed across the individual's lifespan and even into the subsequent generation. Though mechanistic investigations regarding the consequences of developmental cannabis exposure remain sparse, human and animal studies have begun to reveal specific epigenetic disruptions in the brain and the periphery. In this article, we focus attention on long-term disturbances in epigenetic regulation in relation to prenatal, adolescent and parental germline cannabinoid exposure. Expanding knowledge about the protracted molecular memory could help to identify novel targets to develop preventive strategies and treatments for behaviors relevant to neuropsychiatric risks associated with developmental cannabis exposure.

Challenges towards Revitalizing Hemp: A Multifaceted Crop

Hemp has been an important crop throughout human history for food, fiber, and medicine. Despite significant progress made by the international research community, the basic biology of hemp plants remains insufficiently understood. Clear objectives are needed to guide future research. As a semi-domesticated plant, hemp has many desirable traits that require improvement, including eliminating seed shattering, enhancing the quantity and quality of stem fiber, and increasing the accumulation of phytocannabinoids. Methods to manipulate the sex of hemp plants will also be important for optimizing yields of seed, fiber, and cannabinoids. Currently, research into trait improvement is hindered by the lack of molecular techniques adapted to hemp. Here we review how addressing these limitations will help advance our knowledge of plant biology and enable us to fully domesticate and maximize the agronomic potential of this promising crop.

Pharmacologic Implications of Marijuana Use During Pregnancy

Marijuana is the most commonly used recreational drug in the United States, including among women of childbearing age and women who are pregnant. Changing legal statutes that allow for the use of medical marijuana and the decriminalization of marijuana for personal use reflect more permissive societal views on the use of this drug. Active compounds in marijuana cross the placenta rapidly and are excreted in breast milk. Results of studies of the effects of marijuana on a developing fetus and neonate are conflicting, but researchers have identified chronic marijuana exposure as a risk factor for preterm birth and small-for-gestational-age infants. This article reviews the pharmacology of marijuana and discusses implications for nurses who work with women of childbearing age.

Endocannabinoid regulation of β-cell functions: implications for glycaemic control and diabetes

Visceral obesity is a major risk factor for the development of insulin resistance which can progress to overt type 2 diabetes (T2D) with loss of β-cell function and, ultimately, loss of β-cells. Insulin secretion by β-cells of the pancreatic islets is tightly coupled to blood glucose concentration and modulated by a large number of blood-borne or locally released mediators, including endocannabinoids. Obesity and its complications, including T2D, are associated with increased activity of the endocannabinoid/CB1 receptor (CB1 R) system, as indicated by the therapeutic effects of CB1 R antagonists. Similar beneficial effects of CB1 R antagonists with limited brain penetrance indicate the important role of CB1 R in peripheral tissues, including the endocrine pancreas. Pancreatic β-cells express all of the components of the endocannabinoid system, and endocannabinoids modulate their function via both autocrine and paracrine mechanisms, which influence basal and glucose-induced insulin secretion and also affect β-cell proliferation and survival. The present brief review will survey available information on the modulation of these processes by endocannabinoids and their receptors, with an attempt to assess the contribution of such effects to glycaemic control in T2D and insulin resistance.

An Event-Related Potential Study on the Effects of Cannabis on Emotion Processing

The effect of cannabis on emotional processing was investigated using event-related potential paradigms (ERPs). ERPs associated with emotional processing of cannabis users, and non-using controls, were recorded and compared during an implicit and explicit emotional expression recognition and empathy task. Comparisons in P3 component mean amplitudes were made between cannabis users and controls. Results showed a significant decrease in the P3 amplitude in cannabis users compared to controls. Specifically, cannabis users showed reduced P3 amplitudes for implicit compared to explicit processing over centro-parietal sites which reversed, and was enhanced, at fronto-central sites. Cannabis users also showed a decreased P3 to happy faces, with an increase to angry faces, compared to controls. These effects appear to increase with those participants that self-reported the highest levels of cannabis consumption. Those cannabis users with the greatest consumption rates showed the largest P3 deficits for explicit processing and negative emotions. These data suggest that there is a complex relationship between cannabis consumption and emotion processing that appears to be modulated by attention.

In Vitro Propagation of Cannabis sativa L. and Evaluation of Regenerated Plants for Genetic Fidelity and Cannabinoids Content for Quality Assurance

Cannabis sativa L. (Marijuana; Cannabaceae), one of the oldest medicinal plants in the world, has been used throughout history for fiber, food, as well as for its psychoactive properties. The dioecious and allogamous nature of C. sativa is the major constraint to maintain the consistency in chemical profile and overall efficacy if grown from seed. Therefore, the present optimized in vitro propagation protocol of the selected elite germplasm via direct organogenesis and quality assurance protocols using genetic and chemical profiling provide an ideal pathway for ensuring the efficacy of micropropagated Cannabis sativa germplasm. A high frequency shoot organogenesis of C. sativa was obtained from nodal segments in 0.5 μM thidiazuron medium and 95 % in vitro rhizogenesis is obtained on half-strength MS medium supplemented with 500 mg/L activated charcoal and 2.5 μM indole-3-butyric acid. Inter Simple Sequence Repeats (ISSR) and Gas Chromatography-Flame Ionization Detection (GC-FID) are successfully used to monitor the genetic stability in micropropagated plants up to 30 passages in culture and hardened in soil for 8 months.

Cold acclimation induces distinctive changes in the chromatin state and transcript levels of COR genes in Cannabis sativa varieties with contrasting cold acclimation capacities

Little is known about the capacity of Cannabis sativa to cold-acclimate and develop freezing tolerance. This study investigates the cold acclimation (CA) capacity of nine C. sativa varieties and the underlying genetic and epigenetic responses. The varieties were divided into three groups based on their contrasting CA capacities by comparing the survival of non-acclimated and cold-acclimated plants in whole-plant freeze tests. In response to the CA treatment, all varieties accumulated soluble sugars but only the varieties with superior capacity for CA could maintain higher levels throughout the treatment. In addition, the varieties that acclimated most efficiently accumulated higher transcript levels of cold-regulated (COR) genes and genes involved in de novo DNA methylation while displaying locus- and variety-specific changes in the levels of H3K9ac, H3K27me3 and methylcytosine (MeC) during CA. Furthermore, these hardy C. sativa varieties displayed significant increases in MeC levels at COR gene loci when deacclimated, suggesting a role for locus-specific DNA methylation in deacclimation. This study uncovers the molecular mechanisms underlying CA in C. sativa and reveals higher levels of complexity regarding how genetic, epigenetic and environmental factors intertwine.

[Cannabis in France, new insights]

France holds the record for cannabis use in Europe, especially among adolescents. This drug of abuse is thus mainly used during a very sensitive period of brain development, education, vehicle driving and development of life projects. In addition, synthetic derivatives of tetrahydrocannabinol (THC), which are more noxious than cannabis itself are now appearing on the market. Traficking and cultivation for personnal use have intensified; products proposed for sale are richer in THC; and some methods of consumption (e-cigarettes, vaporizers, water pipes) increase the supply of THC to the lungs and thence to the body and brain. It is in this context that attempts are being made to legalize this drug of abuse. Other attempts are made to disguise it as a medication. Meanwhile, the list of its psychic as well as physical damages grows longer, with some very severe cases of major injuries. This evolution takes place in spite of numerous warnings expressed by the French Academy of Medicine. Subsequently, it is prompted to carefully and vigorously denounce these events. This will be the aim of this thematic session.

High frequency plant regeneration from leaf derived callus of high Δ9-tetrahydrocannabinol yielding Cannabis sativa L

An efficient in vitro propagation protocol for rapidly producing Cannabis sativa plantlets from young leaf tissue was developed. Using gas chromatography-flame ionization detection (GC-FID), high THC yielding elite female clone of a drug-type CANNABIS variety (MX) was screened and its vegetatively propagated clones were used for micropropagation. Calli were induced from leaf explant on Murashige and Skoog medium supplemented with different concentrations (0.5, 1.0, 1.5, and 2.0 µM) of indole- 3-acetic acid (IAA), indole- 3- butyric acid (IBA), naphthalene acetic acid (NAA), and 2,4-dichlorophenoxy-acetic acid (2,4-D) in combination with 1.0 µM of thidiazuron (TDZ) for the production of callus. The optimum callus growth and maintenance was in 0.5 µM NAA plus 1.0 µM TDZ. The two-month-old calli were subcultured to MS media containing different concentrations of cytokinins (BAP, KN, TDZ). The rate of shoot induction and proliferation was highest in 0.5 µM TDZ. Of the various auxins (IAA, IBA, and NAA) tested, regenerated shoots rooted best on half strength MS medium (1/2 - MS) supplemented with 2.5 µM IBA. The rooted plantlets were successfully established in soil and grown to maturity with no gross variations in morphology and cannabinoids content at a survival rate of 95 % in the indoor growroom.

Targeting the CB2 receptor for immune modulation

Early work on the biology of the components of Cannabis sativa showed evidence for a potential influence on immune regulation. With the discovery of a peripheral cannabinoid receptor associated with immune cells, many laboratories have sought to link the immunoregulatory activities of cannabinoid compounds with this receptor, hoping that such compounds would lack the psychoactive effects of marijuana and other nonspecific cannabinoid agonists. In this report, the authors investigate the role of the cannabinoid CB2 receptor in immune regulation, with particular emphasis on compounds shown to regulate immune cell recruitment. The authors conclude by using the immune cell recruitment model to rationalise cannabinoid CB2 receptor-specific effects in modulating immune disease, particularly the increasing evidence for its role in experimental autoimmune encephalomyelitis and in influencing bone density.

Hemp (Cannabis sativa L.)

Hemp (Cannabis sativa L.) suspension culture cells were transformed with Agrobacterium tumefaciens strain EHA101 carrying the binary plasmid pNOV3635. The plasmid contains a phosphomannose isomerase (PMI) selectable marker gene. Cells transformed with PMI are capable of metabolizing the selective agent, mannose, whereas cells not expressing the gene are incapable of using the carbon source and will stop growing. Callus masses proliferating on selection were screened for PMI expression using a chlorophenol red assay. Genomic DNA was extracted from putatively transformed callus lines and the presence of the PMI gene was confirmed using polymerase chain reaction and Southern hybridization. Using this method, an average transformation frequency of 31.23% +/- 0.14 was obtained for all transformation experiments, with a range of 15.1 to 55.3%.

Determination of mechanical strength properties of hemp fibers using near-infrared fourier transform Raman microspectroscopy

Fourier transform near-infrared (FT-NIR) Raman microspectroscopy was adopted for analyzing the micro mechanical tensile deformation behavior of cellulosic plant fibers. Mechanical strength parameters such as tensile strength, failure strain, and Young's modulus of diversified hemp fibers were determined within the range of single fiber cells and fiber filaments. The analysis of fiber deformation at the molecular level was followed by the response of a characteristic Raman signal of fiber cellulose that is sensitive to the tensile load applied. The frequency shift of the Raman signal at 1095 cm(-1) to lower wavenumbers was observed when the fibers were subjected to tensile strain. Microstructural investigations using electron microscopy under environmental conditions supported the discussion of mechanical properties of hemp fibers in relation to several fiber variabilities. Generally, mechanical strength properties of diversified hemp fibers were discussed at the molecular, microstructural, and macroscale level. It was observed that mechanical strength properties of the fibers can be controlled in a broad range by appropriate mercerization parameters such as alkali concentration, fiber shrinkage, and tensile stress applied to the fibers during the alkaline treatments.

A review of the world cannabis situation

Cannabis is the world's most widely cultivated and consumed illicit drug, but there remain major gaps in our understanding of global cannabis markets. For example, it appears that premium sinsemilla cannabis, often produced indoors in consumer countries, has become more potent in recent years and that its market share is also growing in some areas. This may be leading to greater localization of cannabis markets. It may also be responsible for the increase in the proportion of cannabis users in treatment populations at the international level. Assessing the extent and impact of this trend, however, is hampered both by a lack of international standards on issues such as terminology and by unanswered research questions. In order to arrive at accurate global estimates of the extent of production, there is a need for more scientific data on cannabis yields. On the demand side, more information is required on the question of cannabis dosage and volumes used by both occasional and regular users. Cannabis is not a uniform drug: the impact of using cannabis of differing potencies and chemical compositions needs to be researched. While issues concerning cannabis have been evaluated many times in the past, it remains a highly adaptable plant and, consequently, a dynamic drug, requiring constant reassessment.

[Specific features of microsporogenesis in the hemp of the Shu valley]

Specific features of microsporogenesis were studied in the narcotic drug containing hemp of the Shu valley. Nuclear divisions were investigated from the moment of appearance of the archesporial tissue until the formation of mature pollen grains. A special attention is paid to the detailed cytological analysis of meiosis and defects at all meiotic phases. The defects at anaphase 1 and anaphase 2 did not affect the karyotype constancy and their absence at the tetrad stage can be considered as an evidence of cytological stability of the studied material.

Cannabis: its therapeutic use

This article provides an overview of the issues surrounding the use of cannabis for therapeutic purposes. Examples of some of the ethical issues related to professional practice are discussed. The authors do not advocate legalising cannabis for all, but the therapeutic advantages and disadvantages of using cannabis are highlighted.

Early development of the secretory cavity of peltate glands in Humulus lupulus L. (Cannabaceae)

Early development of the secretory cavity of chemically fixed peltate glands in Humulus lupulus L. showed secretions with different densities, light, gray and dark, in the cytoplasm of disc cells and in the periplasmic space adjacent to the developing secretory cavity. Secretions were detected in the disc cell wall and subsequently in the developing secretory cavity under the subcuticular wall of the sheath. Light and gray secretions in the cavity possessed a membrane-like surface feature. Secretions were in contact with the irregular inner surface of the cuticle. Secretions contributed to the thickening of the cuticle, whereas the membrane-like surface feature contributed to a network of Cannabis striae distributed throughout the cuticle. This study supports an early development and organization of the secretory cavity in H. lupulus, parallel to those in Cannabis, and may represent common features for lipophilic glands in angiosperms.

Plastid development in disc cells of glandular trichomes of Cannabis (Cannabaceae)

Plastids in lipophilic glandular trichomes of chemically fixed (CF) and high pressure cryofixed-cryosubstituted (HPC-CS) bracteal tissues of Cannabis were examined by transmission electron microscopy. In CF preparations, plastids in disc cells prior to secretory cavity formation possessed several lobed and dilated thylakoid-like features. In glands with secretory cavities, thylakoid-like features aggregated to form reticulate bodies that distended regions of the elongated plastids. Electron-gray inclusions evident on the plastid surface appeared continuous with the reticulate body. Inclusions of similar electron density also appeared in the cell cytoplasm, along the plasma membrane, between the plasma membrane and cell wall facing the cavity, and in the secretory cavity in both CF and HPC-CS preparations. The bilayer structure of membranes of the plastid envelope was evident in HPC-CS but not in CF preparations. In HPC-CS preparations, secretions were evident on the plastid surface and were continuous with those in the plastid through pores in the envelope. This study supports an interpretation that these specialized plastids, lipoplasts, synthesize secretions that are transported through the plasma membrane and cell wall to subsequently accumulate in the secretory cavity.