May barley and rye extracts have an allelopathic inhibition effect on weed seedling root development by suppressing mycorrhization?
Barley and rye are commonly-used cover crops (as Ecological Service providing Crops, ESCs), whose allelopathic potential effect is well recognized. The scope of this research was to assess the allelopathic properties of their extracts on weed seed germination and root development. Moreover, we wanted to verify if allelochemicals contained in barley and rye extracts (ACEs) could affect mycorrhization of weed roots in the early stage of germination. Under controlled conditions, the effect of ACE (25 g FW 80 mL-1 H2O) at increasing concentrations was assessed on curly dock (a widespread weed used as a model plant), determining seed germination percentage and seedling root length, compared to a control (water). Curly dock roots were also stained/destained and observed by optical microscope, in order to evaluate the effect of ACE on potential mycorrhization. Results indicated that ACEs significantly affected curly dock seed germination at the most concentrated condition (i.e., 100%). Moreover, the application of ACEs resulted in no weed root elongation, or its significant decrease, in comparison with the untreated control. Furthermore, microscopic analysis evidenced a significant reduction of the early-stage endo-mycorrhization of curly dock roots after ACE treatments, suggesting that a plant, which naturally synthesizes allelochemical compounds, can influence weed presence and growth by regulating mycorrhization and crop-weed interference.
Trinchera, A., Testani, E., Ciaccia, C., Tittarelli, F. and Canali, S. (2015). May barley and rye extracts have an allelopathic inhibition effect on weed seedling root development by suppressing mycorrhization?. Acta Hortic. 1105, 361-368
germination, barley, rye, root elongation, allelochemicals, AM fungi, scanning electron microscopy, ESC