Allelopathy of plants from Deliblato Sands-Serbia I. Allelopathic influence of Festuca vallesiaca

Abstract

The Festuceto-Potentilletum arenariae steppe community is dominated by Festuca vallesiaca Schleich. We investigated its allelopathic influences on seed germination and seedling growth of neighbouring plants (Cynodon dactylon and Lolium perenne), by determining the amount of total phenolics and phenolic acids in the aboveground parts of F. vallesiaca, litter and soil. An aqueous extract of the aboveground parts of F. vallesiaca, hydroponic growth solution in which F. vallesiaca grew, root exudates, its litter, soil and the phenolic-containing fraction from the soil inhibited the seed germination and seedling growth of neighbouring plants. Total phenolic compounds contents followed the order: vegetative F. vallesiaca parts > litter > soil. The same phenolic acids detected in the aboveground parts of the dominant F. vallesiaca were also found in plant litter and soil, but in significantly lower amounts. Phenolics produced in its tissue accumulated in the litter and soil, reaching toxic concentrations, thus inhibiting the seed germination and seedling growth. In addition to other ecological factors, the dominance of F. vallesiaca mainly resulted from its negative allelopathic effects on other species due to the synthesis and secretion of phenolics, which accumulate in the litter and soil.