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A multivariate analysis of morphological divergence of “seeds” (achenes) among ruderal, fibre, oilseed, dioecious/monoecious and marijuana variants of Cannabis sativa L.

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Abstract and Figures

Cannabis sativa has been domesticated for stem fibre and oilseed (the two classes are both low in the euphoric cannabinoid THC and called “hemp”), and marijuana (high in THC), and also occurs as weedy, ruderal plants. Achenes (“seeds”) from herbarium collections representative of these classes were assessed for morphological characters and pericarp resistance to fracture. In contrast to ruderal plants, domesticated plants (both hemp and marijuana) possessed achenes that were significantly longer, heavier, covered with a less adherent perianth, and lacking a pronounced basal attenuation. All of these characteristics reflect traits that are advantageous in domesticated plants and are consistent with the “domestication syndrome” found in propagules of other crops. Marijuana achenes, in comparison with hemp achenes, tended to be about 26% shorter and about 32 shades darker (on a 256-bit grayscale). Achenes of fibre cultivars proved to be about 19% longer than the achenes of oilseed cultivars. Achenes of dioecious oilseed cultivars proved to be about 6% longer than the achenes of monoecious oilseed cultivars. The pericarps of hemp seeds were about 26% and about 15% more resistant to fracture than those of ruderal and marijuana plants, respectively.
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A multivariate analysis of morphological divergence
of ‘‘seeds’’ (achenes) among ruderal, fibre, oilseed,
dioecious/monoecious and marijuana variants of Cannabis
sativa L.
Steve G. U. Naraine .Ernest Small .Andrew E. Laursen .
Lesley G. Campbell
Received: 30 April 2019 / Accepted: 21 October 2019 / Published online: 30 October 2019
ÓSpringer Nature B.V. 2019
Abstract Cannabis sativa has been domesticated for
stem fibre and oilseed (the two classes are both low in
the euphoric cannabinoid THC and called ‘‘hemp’’),
and marijuana (high in THC), and also occurs as
weedy, ruderal plants. Achenes (‘‘seeds’’) from
herbarium collections representative of these classes
were assessed for morphological characters and peri-
carp resistance to fracture. In contrast to ruderal plants,
domesticated plants (both hemp and marijuana) pos-
sessed achenes that were significantly longer, heavier,
covered with a less adherent perianth, and lacking a
pronounced basal attenuation. All of these character-
istics reflect traits that are advantageous in domesti-
cated plants and are consistent with the
‘domestication syndrome’’ found in propagules of
other crops. Marijuana achenes, in comparison with
hemp achenes, tended to be about 26% shorter and
about 32 shades darker (on a 256-bit grayscale).
Achenes of fibre cultivars proved to be about 19%
longer than the achenes of oilseed cultivars. Achenes
of dioecious oilseed cultivars proved to be about 6%
longer than the achenes of monoecious oilseed culti-
vars. The pericarps of hemp seeds were about 26% and
about 15% more resistant to fracture than those of
ruderal and marijuana plants, respectively.
Keywords Achenes Domestication Cannabis
sativa Ditchweed Hemp Marijuana
Taxonomic variation and domestication history
Cannabis is usually considered to have one species, C.
sativa L., although the names C. indica Lamarck
(usually designating marijuana strains) and C. ruder-
alis Janischevsky (usually labelling ruderal popula-
tions) are also encountered in the literature. Various
infraspecific classifications are also encountered (re-
viewed in Small, 2015,2016,2017). All biotypes of C.
sativa appear to be completely interfertile and there
are no genetic barriers to interbreeding (Small 1972).
Prodigious quantities of pollen are produced and
distributed by wind over considerable distances (Small
and Antle 2003), so spontaneous matings among
populations have doubtless homogenized the gene
pool of C. sativa (Gilmore et al. 2003; Dufresnes et al.
2017). Moreover, humans have very extensively
deliberately cross-pollinated traditional land races
S. G. U. Naraine A. E. Laursen L. G. Campbell (&)
Department of Chemistry and Biology, Ryerson
University, 350 Victoria St, Toronto, ON M5B 2K3,
S. G. U. Naraine E. Small
Ottawa Research and Development Centre, Agriculture
and Agri-Food Canada, Central Experimental Farm,
Ottawa, ON K1A 0C6, Canada
Genet Resour Crop Evol (2020) 67:703–714,-volV)(0123456789().,-volV)
Content courtesy of Springer Nature, terms of use apply. Rights reserved.
... The direct consequence of this selection was the unaware artificial creation of the C. sativa L. varieties, each with specific genotypic and phenotypic features, which at first, induced the taxonomists and botanists to erroneously recognize two or three different species of C. sativa L., embracing a polytypic concept of the Cannabis genus [27]. To further complicate the taxonomic classification of the Cannabis genus, there has been also the fact that C. sativa L. is a crop which tends to exist in "crop-weed complexes", that is complexes of domesticated forms in cultivation and related ruderal (weedy) forms growing outside of cultivation, developing morphological characteristics also very different from those of the domestic progenitor, as a consequence of adaptation to the wild environment [28]. However, it must be considered that, despite the high genetic variability of C. sativa L., the varieties that genotypically and phenotypically differ, are interfertile. ...
... As mentioned above, the C. sativa L. crop has a prehistoric use as an important source of industrial interest's plant fibre. Nevertheless, in the last decades, there has been a growing interest in the seed of the plant which is the fruit of hemp, commonly named seed, even if it is technically an achene, namely an one-seeded dry fruits in which the pericarp is not as tightly joined to the seed, essentially similar to the cereal caryopsis [28]. Normally, the seeds of hemp grown for fibre production were considered as a waste product, and at most, they were mainly used as animal feed [34,41]. ...
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Hempseeds, the edible fruits of the Cannabis sativa L. plant, were initially considered a by-product of the hemp technical fibre industry. Nowadays, following the restorationing of the cultivation of C. sativa L. plants containing an amount of delta-9-tetrahydrocannabinol (THC) <0.3% or 0.2% (industrial hemp) there is a growing interest for the hempseeds production due to their high nutritional value and functional features. The goal of this review is to examine the scientific literature concerning the nutritional and functional properties of hempseeds. Furthermore, we revised the scientific literature regarding the potential use of hempseeds and their derivatives as a dietary supplement for the prevention and treatment of inflammatory and chronic-degenerative diseases on animal models and humans too. In the first part of the work, we provide information regarding the genetic, biochemical, and legislative aspects of this plant that are, in our opinion essential to understand the difference between “industrial” and “drug-type” hemp. In the final part of the review, the employment of hempseeds by the food industry as livestock feed supplement and as ingredient to enrich or fortify daily foods has also revised. Overall, this review intends to encourage further and comprehensive investigations about the adoption of hempseeds in the functional foods field.
... For each reference, the following information is provided: type and year of publication, country and region, taxon, vernacular name, and part of the plant (inflorescence, leaf, whole plant, seed, aerial parts, stem, bark, root, twigs and branches, other parts) or plant product (resin, fibre, other products) used. In the database, the term 'seed' refers to the monosperm Cannabis fruit, a nut (also called achene) (Naraine et al., 2020). It contains information of the type of use, whether Cannabis had animal or human use, and includes modes of preparation and administration, whenever they were provided by the authors. ...
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Ethnopharmacological relevance: Cannabis is one of the most versatile genera in terms of plant use and has been exploited by humans for millennia. Nowadays, Cannabis is the centre of many scientific studies, most of them focusing on chemical composition and medicinal values. While new and varied applications are continuously being developed, the knowledge surrounding less common uses of the plant is slowly disappearing. Aim of the review: We have analysed diversity of global data of Cannabis traditional uses, to investigate if certain plant parts are significantly associated with particular Cannabis use. We wanted to uncover potential associations between the plant parts used for the treatment of different body systems and ailments. Materials and methods: We have analysed the extensive database of Cannabis traditional uses (CANNUSE). This database contains 2330 data entries of Cannabis ethnobotanical uses from over 40 countries across the world. The dataset was divided into five general groups based on the type of use: medicinal, alimentary, psychoactive, fibre and other uses. Given the abundance of human medicinal uses, detailed analysis was done on the subset of 1167 data entries. We analysed the relationship between 16 body system categories and ailments treated with Cannabis plant parts. We used a Pearson's chi-square and Fisher's exact test, to determine which Cannabis parts are characteristic of treatment for specific ailments. Results: In this dataset, the majority of reports were represented by medicinal (75.41%), followed by psychoactive (8.35%) and alimentary (7.29%) use. The most commonly used plant parts were leaf (50.51%), seed (15.38%) and inflorescence (11.35%). We found that different Cannabis plant parts were significantly associated with different uses; the leaf was typically used for medicinal, seed for alimentary and inflorescence for psychoactive use. Regarding the human medicinal uses, most common were reports for treatments of the digestive system and nutritional disorders (17.66%), nervous system and mental disorders (16.24%), followed by pain and inflammations (12.21%). We found a significant relationship between the use of certain Cannabis parts and treatment of ailments and body systems categories; leaf was significantly associated with treatment of two categories: skin and subcutaneous tissue disorders and circulatory system and blood disorders; seed use was associated with musculoskeletal system disorders and traumas; while inflorescence use shows a statistical support for treatment of nervous system and mental disorders. Conclusion: Several pharmaceutical companies are intensely working on developing new drugs with isolated chemical compounds or crude extracts, almost exclusively from Cannabis inflorescences. However, our review revealed that use of leaf or seed in traditional medicine is often more important than use of inflorescence for the treatment of certain ailments. A review of traditional medicine provides a body of knowledge and an initial pathway to identify landraces and plant parts that could have an important role in future medicinal research. We are confident that traditional medicine still has a large potential for modern medicine. As more information on Cannabis diversity (genetics, biochemistry, and clinical studies) becomes available, ethnobotanical data are poised to be of much greater significance.
... 7 More recently, achenes were analyzed in relation to their general biochemical characteristics, which allowed the authors to distinguish ruderal from domesticated plants, as well as psychoactive Cannabis (high-THC) versus hemp (very low-THC, for fiber and oilseed). 8 In this context, it would be helpful to have the possibility to rapidly predict varieties or even chemovars by using the morphology of the achenes in the ever-growing Cannabis industry, before the effort of growing plants has been invested. ...
Introduction:Cannabis plant uses are widespread across human cultures. The current tendency is to classify Cannabis varieties into chemovars upon their chemical fingerprint, mainly cannabinoids and terpenoids content. The identification of chemovars has important medical implications; however, their pharmacological characterization is costly and time consuming. The goal of this study was to assess whether achene shape variation could be related to Cannabis varieties with contrasting cannabinoid concentrations, as a first approach to chemovar identification. Methods: We used two-dimensional geometric morphometrics (GM) of the achenes and multivariate statistical analysis. We used achenes from five varieties, two from Type II chemotype (expressing both tetrahydrocannabinol [THC] and cannabidiol [CBD]), two Type I (THC-only), and one Type III (CBD-only). Results: The achenes from the different chemotypes were clearly distinguishable. No significant differences between varieties from the same chemotype were observed. The varieties with high THC concentration (Type I) were rounded and bigger, whereas achene from varieties containing only CBD (Type III) had a slender shape with smaller size. Conclusion: Achene shape variation is a potential biomarker of cannabinoid content in the plant flowers. Further studies are needed to confirm the suitability of GM methods for high-throughput screening of Cannabis cultivars, including larger diversity of varieties, and taking into account growth conditions, which can also influence plant chemical fingerprint.
... For each reference, the following information was recorded ( Figure 1): (i) type and year of publication, (ii) country, (iii) region, (iv) taxon, (v) vernacular names and (vi) part of the plant (inflorescence, leaf, whole plant, seed, aerial part, stem, bark, root, twig and branch, and other part) or plant product (resin, fibre and other product) used. In this database, the term 'seed' actually refers to the Cannabis fruit-a nut (also called achene) (21). In the reviewed literature, this part was referred to with several terms (fruit, young fruit, nut, achene and seed); because the term 'seed' was the most commonly used and generally accepted, the part was referred to in the database under the single term. ...
Full-text available
Cannabis is one of the most versatile genera in terms of plant uses and has been exploited by humans for millennia due to its medicinal properties, strong fibres, nutritious seeds and psychoactive resin. Nowadays, Cannabis is the centre of many scientific studies, which mainly focus on its chemical composition and medicinal properties. Unfortunately, while new applications of this plant are continuously being developed, some of its traditional uses are becoming rare and even disappearing altogether. Information on traditional uses of Cannabis is vast, but it is scattered across many publication sources in different formats, so synthesis and standardization of these data are increasingly important. The CANNUSE database provides an organized information source for scientists and general public interested in different aspects of Cannabis use. It contains over 2300 entries from 649 publications related to medicinal, alimentary, fibre and other uses from different geographical areas and cultures around the world. We believe this database will serve as a starting point for new research and development strategies based on the traditional knowledge. Database URL:
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Cannabis: Evolution and Ethnobotany is a comprehensive, interdisciplinary exploration of the natural origins and early evolution of this famous plant, highlighting its historic role in the development of human societies. Cannabis has long been prized for the strong and durable fiber in its stalks, its edible and oil-rich seeds, and the psychoactive and medicinal compounds produced by its female flowers. The culturally valuable and often irreplaceable goods derived from cannabis deeply influenced the commercial, medical, ritual, and religious practices of cultures throughout the ages, and human desire for these commodities directed the evolution of the plant toward its contemporary varieties. As interest in cannabis grows and public debate over its many uses rises, this book will help us understand why humanity continues to rely on this plant and adapts it to suit our needs.
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Cannabis (hemp and marijuana) is an iconic yet controversial crop. On the one hand, it represents a growing market for pharmaceutical and agricultural sectors. On the other hand, plants synthesizing the psychoactive THC produce the most widespread illicit drug in the world. Yet, the difficulty to reliably distinguish between Cannabis varieties based on morphological or biochemical criteria impedes the development of promising industrial programs and hinders the fight against narcotrafficking. Genetics offers an appropriate alternative to characterize drug vs. non-drug Cannabis. However, forensic applications require rapid and affordable genotyping of informative and reliable molecular markers for which a broad-scale reference database, representing both intra- and inter-variety variation, is available. Here we provide such a resource for Cannabis, by genotyping 13 microsatellite loci (STRs) in 1 324 samples selected specifically for fibre (24 hemp varieties) and drug (15 marijuana varieties) production. We showed that these loci are sufficient to capture most of the genome-wide diversity patterns recently revealed by NGS data. We recovered strong genetic structure between marijuana and hemp and demonstrated that anonymous samples can be confidently assigned to either plant types. Fibres appear genetically homogeneous whereas drugs show low (often clonal) diversity within varieties, but very high genetic differentiation between them, likely resulting from breeding practices. Based on an additional test dataset including samples from 41 local police seizures, we showed that the genetic signature of marijuana cultivars could be used to trace crime scene evidence. To date, our study provides the most comprehensive genetic resource for Cannabis forensics worldwide.
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Crop domestication provides a useful model system to characterize the molecular and developmental bases of morphological variation in plants. Among the most universal changes resulting from selection during crop domestication is the loss of seed and fruit dispersal mechanisms, which greatly facilitates harvesting efficiency. In this review, we consider the molecular genetic and developmental bases of the loss of seed shattering and fruit dispersal in six major crop plant families, three of which are primarily associated with seed crops (Poaceae, Brassicaceae, Fabaceae) and three of which are associated with fleshy-fruited crops (Solanaceae, Rosaceae, Rutaceae). We find that the developmental basis of the loss of seed/fruit dispersal is conserved in a number of independently domesticated crops, indicating the widespread occurrence of developmentally convergent evolution in response to human selection. With regard to the molecular genetic approaches used to characterize the basis of this trait, traditional biparental quantitative trait loci mapping remains the most commonly used strategy; however, recent advances in next-generation sequencing technologies are now providing new avenues to map and characterize loss of shattering/dispersal alleles. We anticipate that continued application of these approaches, together with candidate gene analyses informed by known shattering candidate genes from other crops, will lead to a rapid expansion of our understanding of this critical domestication trait.
Humans have deliberately spread plants worldwide for millennia. The exchange of plants between different and often distant regions first became a mass global phenomenon in the post-Columbian era. Europeans introduced their cultivated and ornamental plants to the newly settled areas and in return made use of the biological wealth of the new regions for introductions into Europe (26,32,91,153). The scale of the introductions corresponded to the extent of the newly discovered regions. First Mediterranean and American species were usually introduced to central Europe, then species from Asia, and later Australian and African species (74,117).
Cannabis sativa has been utilized for millennia, 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”), and secondarily as a source of edible seeds. In domesticating the species for these divergent purposes, humans have altered the morphology, chemistry, distribution and ecology of cultivated forms by comparison with related wild plants. Wild-growing plants appear to be 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. There are conflicting botanical classifications of Cannabis, including splitting it into several alleged species. The different approaches to classifying and naming plants such as Cannabis, with interbreeding domesticated and wild forms, are examined. It is recommended that Cannabis sativa be recognized as a single species, within which there is a high-THC subspecies with both domesticated and ruderal varieties, and similarly a low-THC subspecies with both domesticated and ruderal varieties. Alternative approaches to the classification of Cannabis that do not utilize scientific nomenclature are noted.