INFLUENCE OF PLANT EXTRACTS ON GERMINATION AND POST-GERMINATION DEVELOPMENT OF DIFFERENT SPECIES

The stem and leaves organic solvent (ethanol) extracts of different medicinal plants (Melissa officinalis, Lavandula angustifolia and Achillea millefollium) were assayed at different concentration values for their effects on seed germination and early seedling growth of soybean, bean, rye, wheat and triticale (all amphidiploid hybrid between wheat and rye having protein-rich grain) plant species. The first two plant species are legumes belonging to Fabaceae or Leguminosae family, and the last three mentioned are grains belonging to Poaceae or Gramineae family. All plant ethanol extracts at different concentrations inhibited seed germination and seedling growth as compared to the control and the degree of inhibition increased with the incremental extract concentration. The results of this study suggest that the stem and leaves of medicinal plants contain allelochemicals which Could inhibit seed germination and seedling growth of the plants used in experiments. Possible links between the allelochemicals responsible for the inhibitory effects observed in the present study and the bioactive compounds are discussed based oil the information reported in other fields. Further work is needed to specify and verify the allelochemicals produced by these herbal plants.