Allelopathic effects of Chrysopogon gryllus L. in Chrysopogonetum Pannonicum Stjep.-Ves. steppe community at Deliblato Sands (Serbia)

摘要

The broadleaf tufted grass species Chrysopogon gryllus L. is dominant in meadow-steppe communities at Deliblato Sands. The Chrysopogonetum Pannonicum Stjep.-Ves. community, covers 2.08% surface area and small population of many other plant species also exist. The allelopathic influences of C. gryllus were studied using the seeds and seedlings of Poa pratensis L. and Trifolium an>ense L. (these plants grow between its tussocks, their abundance and cover is low). Total phenolics contents present followed the order: C. gryllus shoots > litter > soil. The phenolic acids (/7-coumaric, ferulic, p-hydroxibenzoic, vanillic and syringic) that were detected in the shoots were also found in partially decomposed litter and soil, but in lower amounts. When cultured in soil beneath C. gryllus, the seed germination and seedling growth were inhibited. The aqueous extract from its shoots, litter and phenolic fraction from the soil inhibited the seed germination and seedling growth of test plants. C. gryllus as thedominant grass influenced other herbaceous plants in steppe community due to synthesis and leaching of phenols, which accumulated in its litter and soil in concentrations toxic to the seed germination and growth of neighbouring plants.