The allelopathic activity of water-soluble biologically active substances from Hyssopus officinalis L. of Marquis varieties and their effect on the root growth of Lepidium sativum L.

Aim. To study the effect of secretions of bioactive water-soluble compounds from leaves, stems, flowers, and the root system of Hyssopus officinalis L. on the root growth of the test sample (Lepidium sativum L.).Materials and methods. To determine the effect of biologically active water-soluble compounds released by hyssop plants, a series of biotests was conducted; the allelopathic activity of leaves, stems, and flowers of H. officinalis L. and its root system were determined. The preparation of extracts of physiologically active substances was carried out according to the method of A. M. Grodzinsky. The allelopathic effect of H. officinalis L. was assessed by the effect of the water extracts of various concentrations (100 %, 50 % and 10 %) on the root length of seedlings of L. sativum L. test objects. The inhibition index was determined by Williamson method.Results and discussion. According to the results of the research, it was found that the allelopathic activity of water-soluble compounds of common hyssop affected the germination and length of seed roots of L. sativum L. as it changed with the age of the plant : in the first year of vegetation, the stimulating effect of aqueous solutions of hyssop on seed germination was observed, in the second year, the stimulating effect decreased, and in the third year of vegetation, the inhibitory effect on seed germination of the test object was observed. Thus, the index of the allelopathic activity also changed.Conclusions. It was found that the highest allelopathic activity of biologically active water-soluble compounds of root secretions, leaves, stems and flowers of H. officinalis L. was during the flowering phase in concentrations of 100 %, 50 % and 10 %, affecting the length of the roots of seedlings of L. sativum L. test objects. At the same time, the maximum stimulating effect on the length of the roots of the test object was in the variant using an aqueous extract of plant flowers of the second year of vegetation in a 10 % concentration. The use of aqueous solutions of plants of the third year of vegetation had an inhibitory effect on the root length of L. sativum L seedlings.