Generalities, types, and differences between cannabis seeds - Dr. Raúl Porras et al.

Pro Secretary of the Consejo Mexicano de Cannabis y Cáñamo. Medical Surgeon, PhD in Biomedical Sciences at the Instituto Nacional de Enfermedades Respiratorias (INER). Certified in Cannabis medicine; he applies his knowledge advising patients under cannabis treatment. Member of the International Association of Cannabinoid Medicine (IACM). Founder and president of Cannapeutas A.C.

THERE IS A GREAT VERSATILITY OF CANNABIS SEED THAT VARIES DEPENDING ON THE CULTIVATION CHARACTERISTICS, THE GENOTYPE THAT CONSIDERS THE PSYCHOACTIVE EFFECTS, INDICO/SATIVO PERCENTAGES, FLAVORS, COLORS, ETC. KNOWING WHAT TYPE OF SEED IS BEING GERMINATED WILL ALLOW SOLVING THE NEEDS OF USING THE RELEVANT MANAGEMENT FOR GOOD DEVELOPMENT AND PRODUCTION.

SEED MORPHOLOGY AND ANATOMY

The seeds have a rigid and hard testa (head) or outer coat to prevent the seed from breaking easily. The pericarp separates the two halves of the shell in half forming a crown at the flat end, allowing the seed to open and begin the germination process (Fig. 1). Inside the seed, the plant’s embryo is located, waiting for optimal conditions of temperature and humidity to initiate the germination. There is also the radicle, which when it manages to emerge from the testa will represent the main root, and the cotyledons, the first pair of leaves that contain macro and micronutrients that will help later in the early development of the seeding. The radicular system has three main functions: serving as an anchor to the soil, providing the plant with water and nutrients, and finally, storing sugars and starches produced during photosynthesis (Fig. 1). Likewise, the stem will grow between the cotyledons and will end in the apical area, where it continues its vertical growth. Depending on the genetics, the color, size, and weight of the seed will vary (Fig. 1).

Figure 1. Morphological structure of the Cannabis seed, where a) External view. b) Cannabis seed longitudinal cut. c) External view without testa. *Depending on the genetics, the color, size, and weight of the seed will vary. [Photo] Jessica Torres, 2021; [Diagram] Izaizel Cruz, 2021.

It is necessary to know the differences between the different types of seeds to make the right choice at the time of cultivation, thus, to have good management, development, and therefore, a good production.

REGULAR SEEDS

Pure genetic seeds, i.e., that have not undergone any type of manipulation and capable of developing plants of excellent quality and exceptionally good production. In addition, they are photo-dependent (or photoperiodic), which means that there must be a change in the photoperiod, a decrease in the hours of light, and an increase in the hours of dark to enter the flowering stage.

Also, these plants can rise female, male, and hermaphrodite plants. Therefore, it is important to know that, if the intention is not the production of seeds, in case of having male plants in the cultivation space, they should be removed so that they do not pollinate the female flowers, and in case of being hermaphrodite, the male flowers should be cut as soon as they are defined. (Piranha, 2020).

THE ATTRACTION FOR GROWERS: FEMINIZED SEEDS

Feminized seeds are those obtained from regular plants modified and developed so that their offspring produce only female plants, i.e., growers do not have to wait to know whether their plants will be female or male. In addition, feminized seeds allow them time to learn how to become better growers.

SEED FEMINIZATION PROCESS

This process consists basically in the application of silver nitrate (AgNO3) to female plants, which will lead to the expression of male traits producing modified pollen, which in turn will fertilize females to produce seeds with a high load of female genetic material, and thus, obtaining a high potential of producing only female plants. Likewise, these plants are also photo-dependent, giving a stable and good quality production, being the Indica varieties the ones that present a shorter time in terms of floral development (Piranha, 2020).

DIFFERENCES BETWEEN THE FEMINIZED INDICA AND SATIVA SEEDS

Currently, most Cannabis seeds contain a mixture of both Indica and Sativa genetics, i.e., they are hybrids with characteristics from both species.

AUTO-FLOWERING SEEDS

By incorporating these genetics in feminized seeds, seeds with faster growth and flowering are obtained. Such plants are not photo-dependent, as their flowering period is determined by the sexual maturity of the plant rather than the decrease of daylight hours. That is, they do not depend on the length of the photoperiod to change from the vegetative to the reproductive stage but begin to flower when they complete a fixed vegetation period (Piranha, 2020).

FAST VERSION SEEDS

Fast Version seeds result from the first offspring of a crossing between a male automatic plant and a feminized one. They are those feminized seeds of short flowering. Likewise, these seeds are also called F1 because of the characteristics of the first filial generation produced from this crossing. This first-generation maintains the traits of the photo-dependent feminized plant with a shorter flowering period (Piranha, 2020).

F1 Fast Version® variants are 100% photo-dependent and ultra-fast flowering including some of the most appreciated genetics of the Sweet Seeds® catalog. These new genetics are F1 hybrids. These marijuana plants are ready to be harvested in indoor crops only 6 to 7 weeks after the change of photoperiod to 12 hours of light and 12 hours of dark; in outdoor crops, plants are harvested 1 or 2 weeks earlier than the original versions. Due to their fast-flowering, these varieties are quite suitable for cultivation in humid, rainy, high mountainous areas or with cold winters, especially sensitive to fungal attacks, as they manage to anticipate their harvest to the most virulent botrytis (gray mold) that decimate the buds of the longest flowering plants.

How to differentiate between seed varieties? It is important to highlight that the identification of the seed genetics comes directly from the seed banks because it is not possible to differentiate at a glance between the different seeds of Cannabis sativa. The comparisons between the aforementioned seed varieties are shown in Table 1.

Table 1. Comparison between different varieties of seeds (indoor crops). Based on Blog Piranha, 2020.

SEEDS USES AND BENEFITS

Hemp seeds and their derivatives such as oil, flour, and powdered protein are considered a superfood due to their nutritional properties; the content in fatty acids, vitamins, proteins, and minerals represent a highly energetic cereal that matches the characteristics of chia, as shown on Table 2 (Fundación CANNA, n.d.; López, 2020).

Table 2. Nutritional values of Cannabis and Salvia hispanica seeds (López, 2020).

Studies on hemp flour demonstrated that it contains a higher amount of calcium, potassium, magnesium, but also, great amounts of dietary fiber compared to the wheat flour control. Despite the severe loss of these compounds due to baking, all bread obtained from hemp products (especially 15% and 25% hemp flour) retained higher amounts of bioactive mineral compounds due to higher initial levels. The hemp products used in the experiments allow us to consider bread variants with higher nutritional value, and thus, incorporate proteins, essential fatty acids, minerals, and dietary fibers into bakery products, improving their quality by substituting a quantity of total flour and thereby, decreasing the total gluten content. For this reason, these bread variants are recommended for people with low gluten tolerance (Bădărău et al., 2018).

In terms of the chemical composition, hemp products contain polyunsaturated fatty acids (PUFA) of around 70% to 80%, with low concentrations of saturated fatty acids (SFA). Among PUFA, linoleic acid was the most representative fatty acid with about half of the total fatty acids. The second prominent PUFA was α-linolenic acid (ALA), commonly known as Omega 3, thus, hemp oil represents a particularly rich source of these two fatty acids, known as Essential Fatty Acids (EFA), as they cannot be synthesized by mammals and therefore, must be acquired in the diet since they are necessary to maintain a healthy human life (Farinon et al., 2020).

Hemp products' high concentration of PUFA, such as Omega-3, has proven to reduce the risk of cardiovascular diseases, the proliferation of different types of cancer, and beneficial effects in the treatment of inflammatory diseases such as rheumatoid arthritis, psoriasis, or Crohn's disease. In addition, the ratio Omega-6 and Omega-3 (n-6/n-3) is favorable since high ratios of Omega-6 to Omega-3 promote the pathogenesis of several diseases, including cardiovascular, autoimmune, and cancer diseases while decreasing this ratio, i.e., increased Omega-3 delivers beneficial effects on health (Fundación CANNA, n.d.).

In 2009, Callaway et al. conducted an experiment in patients with atopic dermatitis, where the efficiency of hemp oil compared to extra virgin olive oil was measured. The experiment was carried out for eight weeks in a group of 20 patients, of whom, only 16 completed the treatment consisting of consuming 30 mL of the study oil, as well as avoiding nutrient supplements, steroids (e.g., skin creams), oral cyclosporine, asthma medications, or solariums during the study and 1 month prior. Preliminary results confirm an improvement in skin after the daily ingestion of small amounts of hemp oil for a relatively short period.

In addition, studies demonstrate that Omega-3 could help solve problems caused by particulate matter pollution with diameters of less than 2.5 microns (2.5 PM), such as cardiovascular diseases, one of the main causes of death around the world. Researchers performed experiments on mice exposed twice a week for 6 weeks to 2.5 PM, showing the presence of a large number of PM particles in the spleen, liver, brain, kidneys, testes, and lung. Several approaches were considered to minimize such effects and found that simple supplementation with Omega-3 fatty acids proved to be effective, as a significant reduction in local and systemic inflammation was observed, significantly decreasing lung inflammation, treating, and preventing health issues caused by PM pollution. Omega-3 supplementation was effective both as prevention (pre-exposure) and intervention (post-exposure). From where is it more convenient to take Omega-3? If we take into account that it could be produced through a sustainable crop that enriches soils and captures carbon, in addition to being low in saturated fatty acids and having the highest total phenolic content and antioxidant activity (compared to other vegetable oils), both playing a key role in reducing the risk of cancer, alleviating systemic inflammation, which acts as a powerful antioxidant and promotes free radical scavenging, the introduction of hemp seeds and hemp seed oil could be a very practical and effective measure in our diet to protect us from air pollution (Bagar, n.d.).

Although most vegetable oils have at least one of the essential fatty acids, it is unusual for them to contain such high amounts of both, but it is also unusual for them to be in a ratio of about 3:1 Omega-6/Omega-3, this being the recommended ratio for human intake. The number of fatty acids present in several vegetable oils is shown in Table 3 (Fundación CANNA, n.d.).

Table 3. Composition of fatty acids in different vegetable oils (Fundación CANNA, n.d.).

In addition, it contains unsaponifiable matter, about 1.8 – 1.92% of the total oil, and the most relevant compounds are tocopherols and phytosterols that can reduce the risk of cardiovascular disease, cancer, and age-related macular degeneration. Besides presenting antioxidant activity, tocopherols are known to be important antioxidants with a positive effect on the oxidative stability of oils (Fundación CANNA, n.d.).

The most abundant isomer is γ-tocopherol, followed by α-, δ- y β-tocopherols. The α-isoform is considered the only bioactive form of tocopherol, i.e., the form with vitamin E activity in the human body. But what is the daily intake of vitamin E as α-tocopherol? The European Food Safety Authority (EFSA) has established an average intake of 13 mg/day for men and 11 mg/ day for women. Studies demonstrate that the content of α-tocopherol in hemp seeds can reach up to 5 mg/100 g of seeds. One serving of hemp seeds equals 30 g., therefore, the daily intake of one serving of hemp seed can contribute to satisfying up to 14% for women and 12% for men of vitamin E (Farion et al., 2020).

Also, several studies show benefits of hemp seeds as a livestock supplement, as is the case of Neijat et al., who in 2016 found that, as a consequence of dietary supplementation with hemp seeds and hemp seed oil to the diet of laying hens, the content of alpha-linolenic acid (ALA) increased in a dose-dependent manner.

USES OF ESSENTIAL HEMP OIL

Essential oils for human use can be extracted from the seeds as they have 30% oil content, allowing that about 50% of the global hemp oil market be concentrated in the food industry and nutritional supplements, as it can be used as a flavoring additive; in fact, it has a peculiar nutty flavor and is currently incorporated in many food preparations such as bread, cakes, cookies, vegetable milk, ice creams, etc. (Gabrielová, n.d.). Meanwhile, the other half of the world trade is focused on cosmetic applications such as soaps, shampoos, creams, etc., since it is widely used in relaxation massages with anti-inflammatory effects (Gabrielová, n.d.). But that is not all, it also has other industrial uses such as hemp diesel, a high-quality fuel. In addition, hemp seed oil is historically known to have been used as a fuel for lighting before the advent of electricity (López, 2020).

EXTRACTION METHODS

Vegetable extraction is generally a solid-liquid extraction, also called leaching, whose objectives are:

• Concentrating the active substance

• Obtaining easily digestible substances

• Removing undesirable substances (bad tastes, odors, irritating or toxic substances)

There are several extraction methods, the most common are shown in Table 4 (López, 2020).

Table 4. Comparison between different types of extraction, modified from López, 2020.

Dr. Raúl Porras

Pro Secretary of the Consejo Mexicano de Cannabis y Cáñamo. Medical Surgeon, PhD in Biomedical Sciences at the Instituto Nacional de Enfermedades Respiratorias (INER). Certified in Cannabis medicine; he applies his knowledge advising patients under cannabis treatment. Member of the International Association of Cannabinoid Medicine (IACM). Founder and president of Cannapeutas A.C.

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Izaizel Libertad Cruz y Alejandra Nayeli De Olarte. Biologists Cannapeutas A.C.