The influence of exogenous growth regulators on the cannabinoid content and the main selection traits of hemp (Cannabis sativa L. SSP. sativa)
Institute of Bast Crops of the National Academy of Agrarian Sciences of Ukraine, 45Tereshchenkiv Str., Hlukhiv, Sumy region, 41400, Ukraine (1,2,3)
Institute of Irrigated Agriculture of the National Academy of Agrarian Sciences of Ukraine, Naddniprianske, Kherson, 73483, Ukraine (4,5,6)
Hemp (Cannabis sativa L.) is a species sensitive to the influence of exogenous growth regulators, both in the treatment of vegetative plant tissues and in vitro culture. 1-naphthylacetic acid, indole-3-acetic acid, 2,4-dichlorophenoxyacetic acid, kinetin, 6-benzylaminopurine (BAP), gibberellic acid (GA3), ascorbic acid and nicotinic acid of exogenous origin in the studied concentrations and doses caused a change in the content of cannabinoids in plants of the variety USO31. Ascorbic acid, auxins and GA3 significantly reduced the content of cannabinoids, whereas nicotinic acid and cytokinins increased it. Under the influence of nicotinic acid and BAP, a higher content of cannabinoid compounds was stably manifested during each of the three years of processing and it is inherited by at least one generation of descendants. An additional method to increase the level of non-psychotropic cannabinoids may be the treatment of vegetative plant tissues with cytokinin BAP (the concentration of 40 mg/l, the consumption rate of 30 ml/m2, the phase of growth and development BBCH 51), which, in contrast to high concentrations of nicotinic acid, significantly increased the content of cannabidiol, and, to a lesser extent, tetrahydrocannabinol. The selection traits of the hemp – stem total length, mass and fiber content, seed productivity and sex determination significantly increased under treatment. A wide range of possibilities for phytohormones of exogenous origin in regulating cannabinoid accumulation, morphogenesis of hemp plants and their productivity was confirmed. Different hemp genotypes may have different responses to plant growth regulators and concentrations, which should be established in each case.