Effect of Alginite in the Form of ALGEXr 6 Preparation on the Biomass Formation and Antioxidant Activity of Some Medicinal Plants

Abstract

The aim of the research is to determine the effect of application of the developed product (extract) called ALGEXr 6 from natural mineral rock alginite in two different watering periods on the formation of root biomass and above-ground plant biomass of a selected group of medicinal plants (Melissa officinalis L., Malva verticillata L. and Ocimum x citriodorum Vis.) and determining the antioxidant activity in dried leaves and whole plants in aqueous and methyl alcohol extracts by DPPH method . The experiment was established in the Botanical Garden at the Slovak University of Agriculture in Nitra throughout 2020. ALGEXr 6 was prepared by a research team at the Slovak University of Agriculture in Nitra in the form of an extract from the natural mineral rock alginite with an application of thermal and chemical treatment. In the experiment, ALGEXr 6 was applied in the form of a watering in two variants with the same concentration of 3 % solution in 2 decilitres of water, but various application in terms of days in the pre-harvest stage of the above-ground plant biomass of 30 individual plants from each species. There are two diametrically opposite trends of ALGEXr 6 application that are manifesting themselves in M. officinalis and M. verticillata by reducing the root and above-ground part biomass compared to the control variant. The percentage proportionality of root/above-ground part biomass in M. officinalis decreased from 62.48 /30.31 % (control), to 45.57/18.85 % (variant 1) and to 36.07/17.27 % (variant 2), as well as in M. verticillata the root/above-ground part biomass decreased from 16.03/13.93 % (control), to 14.97/9.42 % (variant 1) and to 11.61/10.14 % (variant 2). In the species Ocimum x citriodorum Vis. the opposite trend manifested. The application of ALGEXr 6 watering resulted in increasing the antioxidant activity on the tested plant parts, especially in aqueous extracts in M. officinalis (from 19.30/control to 33.61 %/variant 1, 2), also in O. citriodorum (from 26.56/control to 44.16 %/variant 1), while in methyl alcohol extracts, the antioxidant activity showed a slight increase in all tested species.