E. Aryakia - Plant Bank, Iranian Biological Resource Center (IBRC), ACECR, Tehran, Islamic Republic of Iran.
M. R. Naghavi - Department of Agronomy and Plant Breeding, University College of Agriculture and Natural Resources, University of Tehran, Karaj, Islamic Republic of Iran.
Z. Farahmand - Plant Bank, Iranian Biological Resource Center (IBRC), ACECR, Tehran, Islamic Republic of Iran.
A. A. H. Shahzadeh Fazeli - Plant Bank, Iranian Biological Resource Center (IBRC), ACECR, Tehran, Islamic Republic of Iran.

Plant tissue culture technique could provide sterile and controllable condition in order to assay direct effect of different compounds on plant growth accurately. In this study, the effects of aqueous extracts prepared from roots and shoots of goosefoot (Chenopodium album L.), redroot pigweed (Amaranthus retroflexus L.), fennel (Foeniculum vulgare), and wormwood (Artemisia absinthium L.) were evaluated on the seed germination and growth criteria in tissue culture media. The fennel root extract, nearly without phenolic content and with low antioxidant activity, showed the most drastic allelopathic effect on goosefoot, especially at ۱۰۰ mg mL-۱ concentration, which might be due to the presence of some substance potentially useful for biological control of goosefoot, an invasive weed. Goosefoot was resistant to extract of fennel shoot, wormwood root, and shoot, while fennel and radish (Raphanus sativus L.), at high concentration (۱۰۰ mg mL-۱), were not resistant to the root and shoot extracts of both goosefoot and redroot pigweed. In response to allelopathic components, shoot:root ratio was increased, and more peroxidase and superoxide dismutase activity were detected in roots. There was no direct relationship between allelopathic effects with total phenolic content and antioxidant activity. In conclusion, our results showed that allelopathic effects of extracts on growth and biochemical criteria depended on both the concentration levels and the plant parts from which the aqueous extract was derived. Therefore, tissue culture media is an accurate and suitable tool to screen plants resistant to allelopathic components of weeds, and to identify high allelopathic plants as potential bioherbicide and invasive plant controller.

Aqueous extract, Growth criteria, Invasive plant, Total phenolic content, Antioxidant activity