Evaluating Allelopathic Effects of Some Plant Species in Tissue Culture Media as an Accurate Method for Selection of Tolerant Plant and Screening of Bioherbicides

Abstract

Plant tissue culture technique could provide steril e and controllable condition in order to assay direct effect of different compounds on pl ant 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 e xtract, nearly without phenolic content and with low antioxidant activity, showed the most drastic allelopathic effect on goosefoot, especially at 100 mg mL -1 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 (100 mg mL -1 ), were not resistant to the root and shoot extracts of both go osefoot and redroot pigweed. In response to allelopathic components, shoot:root ratio was in creased, and more peroxidase and superoxide dismutase activity were detected in root s. There was no direct relationship between allelopathic effects with total phenolic co ntent and antioxidant activity. In conclusion, our results showed that allelopathic ef fects of extracts on growth and biochemical criteria depended on both the concentra tion levels and the plant parts from which the aqueous extract was derived. Therefore, t issue culture media is an accurate and suitable tool to screen plants resistant to allelop athic components of weeds, and to identify high allelopathic plants as potential bioherbicide and invasive plant controller. Keywords : Aqueous extract, Growth criteria, Invasive plant, Total phenolic content, Antioxidant activity.