THE UNIQUENESS OF BIOLOGICAL CHARACTERISTICS OF TECHNICAL HEMP AND PROSPECTS FOR ITS PRACTICAL USE

The results of studying biological characteristics and performance features of monoecious hemp varieties are presented. New hemp varieties bred in Ukraine are unique because technical hemp plants produce fiber, seeds, oil and do not accumulate narcotic compounds. Along with universal varieties, varieties with increased yields of seeds, oil, fiber and stem biomass were developed. The first medicinal hemp varieties with increased contents of cannabidiol (CBD) and cannabigerol (CBG) were obtained, and they can also be used as a technical crop. odor, cross-pollinating, heterozygosity, sexual polymorphism, dominance of the cannabinoid presence, direct correlation between the contents of cannabidiol and tetrahydrocannabinol, formation of glandular trichomes and essential oils on leaves and perianths. of tetrahydrocannabinol does not exceed 0.08%. The breeding methods developed to increase the cannabidiol content made it possible to create new starting material stabilized in terms of the cannabidiol and tetrahydrocannabinol contents at the level of 1.5–3.0 and 0.04–0.07%, respectively. For the time, we established that there was no relationship between CBG and THC. Targeted selection for increase in the CBG content led to the creation of hemp variety Vik 2020 with a cannabigerol content of up to 1.0% and without THC. Conclusions. The results obtained prove the uniqueness of technical hemp as a biological object of research, possibilities of developing new scientific theories, breeding methods, genetic mechanisms of cannabinoid synthesis and practical of and medicinal in different production advanced processing 34–38

tetrahydrocannabinol (THC), in the 1960s-70s was 0.3-0.5%. Longer than 40-year work resulted in hemp varieties without any drug activity. In the process of seed production to certified seeds, registered hemp varieties do not accumulate narcotically active tetrahydrocannabinol more than 0.05%. Therefore, the problem of the social safety of technical hemp has been solved via breeding.
Purpose and objectives. The study purpose was development of new hemp varieties of for different uses, identification of biological characteristics of the monoeciousness traits and diversity of cannabinoid compounds, and evaluation of prospects of developing varieties for seeds, fiber, oil, and medicinal drugs.
Material and methods. Hemp varieties grown in breeding variety trials and breeding nurseries were taken as the test material. The oil content was determined by C.V. Rushkovsky's method; the fatty acid composition of oilby gas chromatography on a chromatograph Selmichrom-1; the contents of cannabinoids and terpenesby an internal standard method on a gas-liquid chromatograph HP 6890 Series Hewlett Packard. Relationships between the traits were assessed with correlation coefficients.
Results and discussion. Breeding approaches to reduce the content of narcotically active tetrahydrocannabinol (THC) were quite stringent. At the early stages, family-group selection of plants with decreased contents of cannabinoids negatively affected the performance, especially the weight of seeds from elite plants. Subsequently, when the population expanded, selection for increased fiber content as well as seed and stem yields became possible. The breeders' objective was to preserve the main benefit of hemp -formation of the bast-fiber layer on stems.
The first high-yielding monoecious hemp variety YUSO 31, which could be used both for fiber and for seeds and had a decreased THC content, was entered in the State Register of Varieties in 1987. Currently, this variety is the standard of several traits (early maturity, low THC content, high fiber and oil contents, yield and inflorescences habit) in the world breeding practice.
The breeding was hampered because of a number of biological features of hemp: specific odor, cross-pollinating, heterozygosity, sexual polymorphism, dominance of the cannabinoid presence, direct correlation between the contents of cannabidiol and tetrahydrocannabinol, formation of glandular trichomes and essential oils on leaves and perianths.
Essential oil from narcotic hemp C. indica is known to contain 0.015% of THC and more than 137 terpenes with a maximum content of β-Caryophyllene, Terpinolene, β-Myrcene, α-Pinene, Trans-β-Ocimene (68.42%). Studies have shown that plants with a high THC content, including vegetative and generative organs (stems, leaves, and perianths), are covered with cystolith and glandular hairs of all 3 types (bulbous, sessile, and stalked), with the largest number of them on perianths. Trichome heads are filled with brown liquid.
C. sativa plants also have a specific hemp smell, essential oils and glandular hairs. However, they are less pronounced than those of narcotic hemp and even within this species their manifestation weakens when the cannabinoid content is reduced to a minimum. Changes in the hair structure are also noted. In technical hemp varieties with a tetrahydrocannabinol content of 0.01%, hairs appear more often as single inclusions on veins of the leaf blade. Trichomes are characterized by smaller hair heads than in plants with higher contents of cannabinoids (0.08% THC). Through the microscope, it is seen that heads are filled with light secretion. In varieties with an increased THC content, there is a direct correlation between the number of glandular hairs and the contents of cannabinoids, and if THC is absent, or if its content is very low, this relationship is broken. Almost all industrial hemp varieties with a minimum THC content or without THC at all were revealed to contain essential oils (0.06-0.24%) [8,9].
In the breeding course, breeding material without the specific odor, trichomes or THC (variety YUSO 45) was distinguished. Continuous breeding towards reducing narcotic contents in hemp led to the development of a new unique variety without not only THC, but without the other cannabinoids (variety Viktoriia) (Fig. 1).
Hemp breeding is also complicated by sex polymorphism, the ontogenetic and phylogenic characteristics of which are determined by the habit factors and the male/female flowers ratio. At the same time, permanent mutationssex mosaicslargely influence the genotypic expression of sexual characteristics. According to different theories of hemp sex genetics, there are from 5 sexual types of monoecious plants (Neuer, Sengbusch, 1943) to 22 sexual types of masculinized and feminized plants (N.N. Grishko, 1940). According to an improved classification, 12 sexual types of dioecious and monoecious hemp are considered (N.D. Migal, 1992) [10]. Male hemp plants are the main destabilizer of monoecious hemp populations (Fig. 2). Therefore, during the propagation of a variety to the 2 nd reproduction (certified seeds), the number of such plants is limited to 1% by the international standard EU.  % tions with such plants decreases segregation into undesirable sex types, including non-productive masculinized plants and late-ripening feminized male plants (Fig. 3).

Fig. 3. A Monoecious Feminized Female plant and an Inflorescence Fragment
Moreover, such a population with a high percentage of monoecious feminized female plants ensures a consistently high performance of the variety.
Modern hemp varieties are noticeable for multipurposeness: for fiber, seeds, oil. At the same time, there are check varieties (variety Hliana) with a certain yield (fiber and oil contents -30%, stem yield -7.5-8.0 t/ha, and seed yield -1.0-1.2 t/ha) and specialized varietiesfor fiber, seeds and oil. The peculiarity of these varieties with high values of one parameter is that they can also be used for processing all parts of plants.
Foe example, monoecious hemp variety Hlukhivskyi 51 has up to 38-40% of fiber in stems, the stem biomass is 8.5-10.0 t/ha, and the yield of seeds with an oil content of 28% is 0.8-0.9 t/ha. This variety is highly profitable in fiber production (3.2-3.8 t/ha [the check variety gives 2.0-2.2 t/ha]) and production of hards (55-60%), which can be used to manufacture pellets, briquettes and biocomposite materials. Seeds obtained upon harvesting for double use are processed to produce oil.
Seed variety Hlesіia is characterized by a maximum seed yield (up to 1.8 t/ha), high oil content (34%) and a medium fiber content (up to 28%).
Hemp variety Mykolaichyk has an increased oil content in seeds of 38-40%, seed yield of up to 1.5 t/ha and fiber content of 28% (Table 1). The uniqueness of this variety also lies in the fatty acid composition of seed oil. The ratio of omega-6 to omega-3 (ω-6:ω-3) polyunsaturated fatty acids of 4:1 is considered to be the best one. In this variety, the ratio ranges 3:1 to 4:1 from year to year. The content of gamma-linolenic acid is 2.53%. Today, hemp hulled seeds are introduced in nutrition practice, and their value significantly increases with the optimal ratio of omega-6 to omega-3 fatty acids and an increased amount of -linolenic acid ( Table 2). If previously it was believed that synthesis of cannabinoids is a negative feature, now after extraction of pure substances and research into their biological and medicinal properties, it became known about possibilities of their use for medical purposes. At present, cannabidiol (CBD), cannabichromene (CBC), cannabigerol (CBG), cannabinol (CBN), cannabidivarin (CBDV) are considered the most valuable ones. Studies of several hemp varieties (Santica, Fedora, Felina, Ferimon, YUSO 31) also found acid analogues of some cannabinoids -CBGA, CBDA, and THCA. Of these varieties, YUSO 31 has the lowest THC content. It should also be noted that plants of this variety differ in many of the above-listed cannabinoids and their acids. Such cannabinoid compounds as CBC, CBG, CBN and CBDV appeared in small leaves during seed maturation. The greatest amount of CBG was detected in plants of varieties Santica and YUSO 31, while CBD and CBDA were found in all the varieties under investigation, but with a strong variability of the trait from 0.000% to 5.12% (Table 3). Moreover, the maximum levels of CBD and CBDA are associated with the maximum amounts of THC and THCA. In this regard, investigations are is underway to search for such hemp forms that have a high CBD content and a low THC content, not exceeding the legally limited standard. In the EU, it is 0.2%; in the United States -0.3%; in Russia -0.1%; and in Ukraine -0.08% of THC. As one can see, the most severe restrictions are set in Ukraine, even for research.
At the first stage of our studies, it was necessary to find out how close the correlation between the CBD and THC contents was and the limits of increasing the CBD level without ex-ceeding the THC content limit [11,12]. It was found that the correlation between the CBD and THC levels is close to 1 (r = 0.7-0.9).
The direct dependence of synthesis of one cannabinoid on another restricts breeding for an increased cannabinoid content in the range of 1.5-3.0%. In this case, the content of tetrahydrocannabinol does not exceed 0.08% [13.14].
The breeding methods developed to increase the cannabidiol content made it possible to create new starting material (variety Mriia) stabilized in terms of the cannabidiol and tetrahydrocannabinol contents at the level of 1.5-3.0 and 0.04-0.07%, respectively.
For the first time, we established that there was no relationship between CBG and THC. Targeted selection for increase in the CBG content led to the creation of hemp variety Vik 2020 with a cannabigerol content of up to 1.0% and without THC.
In the future, the breeding methods developed will allow creating hemp varieties both with combinations of therapeutic cannabinoids, thereby increasing their medical value, and with individual cannabinoids: cannabinol, cannabichromene, and cannabidivarin, without any narcotic effects.

Conclusions.
The results obtained prove the uniqueness of technical hemp as a biological object of research, possibilities of developing new scientific theories, breeding methods, genetic mechanisms of cannabinoid synthesis and practical use of such hemp products as oil, hulled seeds, fiber and medicinal agents in different production areas, where, as more advanced processing techniques are developed, the effectiveness of hemp rises.
The technical hemp varieties, universal, seed and fiber ones, are noticeable for the absence of THC and CBD and can be used for fiber (the fiber content is 30, 28 and 38% in universal, seed and fiber varieties, respectively), seeds (the seed yield is 1.0-1.2, 1.5-1.8 and 0.8-0.9 t/ha in universal, seed and fiber varieties, respectively) and oil (the oil content in seeds is 30, 34-38 and 28% in universal, seed and fiber varieties, respectively).
For the first time in the history of hemp breeding, studies have has been conducted to develop medicinal hemp varieties.

THE UNIQUENESS OF BIOLOGICAL CHARACTERISTICS OF TECHNICAL HEMP AND PROSPECTS FOR ITS PRACTICAL USE
Laiko I.M.

Institute of Bast Crops of NAAS, Ukraine
Purpose and objectives. The study purpose was development of new hemp varieties of for different uses, identification of biological characteristics of the monoeciousness traits and diversity of cannabinoid compounds, and evaluation of prospects of developing varieties for seeds, fiber, oil, and medicinal drugs. Material and methods. Hemp varieties grown in breeding variety trials and breeding nurseries were taken as the test material. The oil content was determined by C.V. Rushkovsky's method; the fatty acid composition of oil -by gas chromatography on a chromatograph Selmichrom-1; the contents of cannabinoids and terpenesby an internal standard method on a gas-liquid chromatograph HP 6890 Series Hewlett Packard. Relationships between the traits were assessed with correlation coefficients. Results and discussion. The breeding was hampered because of a number of biological features of hemp: specific odor, cross-pollinating, heterozygosity, sex polymorphism, dominance of the cannabinoid presence, a direct correlation between the contents of cannabidiol and tetrahydrocannabinol, formation of glandular hairs (trichomes) and essential oils on leaves and perianths. It was demonstrated that in varieties with an increased THC content there was a direct correlation between the number of glandular hairs and the contents of cannabinoids, and if THC is absent, or if its content is very low, this relationship is broken. Almost all industrial hemp varieties with a minimum THC content or without THC at all were revealed to contain essential oils (0.06-0.24%). Hemp breeding is also complicated by sex polymorphism, the ontogenetic and phylogenic characteristics of which are determined by the habit factors and the male/female flowers ratio.
Universal check variety Hliana is the best variety in terms of sex composition and monoeciousness stability with minimal segregation of male plants in reproductions. There are universal varieties (check variety Hliana) with a certain yield (fiber and oil contents -30%, stem yield -7.5-8.0 t/ha, and seed yield -1.0-1.2 t/ha) and specialized varietiesfor fiber (variety Hlukhivskyi 51, the fiber content is 38-40%), seeds (variety Hlesiia, the seed yield is 1.5-1.8 t/ha) and oil (variety Mykolaichyk, the oil content is 38-40%). The prospects of breeding to create medicinal varieties have been proven. The direct dependence of synthesis of one cannabinoid on another (r = 0.7-0.9) restricts breeding for an increased cannabinoid content in the range of 1.5-3.0%. In this case, the content of tetrahydrocannabinol does not exceed 0.08%. The breeding methods developed to increase the cannabidiol content made it possible to create new starting material stabilized in terms of the cannabidiol and tetrahydrocannabinol contents at the level of 1.5-3.0 and 0.04-0.07%, respectively. For the first time, we established that there was no relationship between CBG and THC. Targeted selection for increase in the CBG content led to the creation of hemp variety Vik 2020 with a cannabigerol content of up to 1.0% and without THC. Conclusions. The results obtained prove the uniqueness of technical hemp as a biological object of research, possibilities of developing new scientific theories, breeding methods, genetic mechanisms of cannabinoid synthesis and practical use of such hemp products as oil, hulled seeds, fiber and medicinal agents in different production areas, where, as more advanced processing techniques are developed, the effectiveness of hemp rises. The technical hemp varieties, universal, seed and fiber ones, are noticeable for the absence of THC and CBD and can be used for fiber (the fiber content is 30, 28 and 38% in universal, seed and fiber varieties, respectively), seeds (the seed yield is 1.0-1.2, 1.5-1.8 and 0.8-0.9 t/ha in universal, seed and fiber varieties, respectively) and oil (the oil content in seeds is 30, 34-38 and 28% in universal, seed and fiber varieties, respectively). For the first time in the history of hemp breeding, studies have has been conducted to develop medicinal hemp varieties. A medicinal hemp variety has been created (variety Mriia). It, in addition to leaf biomass with an increased CBD content, gives a seed yield of 0.8-1.0 t/ha with oil content of up to 28% and a stem yield of 7.0 t/ha with a fiber content of 28-30%. Variety Vik 2020 with an increased content of KBG (1.0%) and without THC has been created.