One of the main weed ways to release allelochemicals is root exudation which is important regulating agent in neighbor microbes and plants. The rhizosphere microbial communities were clearly richness than in non rhizosphere soil at both high and low density areas of filed bindweeds (Convolvulus arvensis L.). Their roots exudates inhibited rhizosphere soil bacteria and fungi in high densities than the low one densities. The EC50 of bindweed ethyl acetate root exudates extract was 1625 µg/g (Lactuca sativa L.), 1360 µg/g (Phalaris paradoxa L.) for seedlings biomass fresh weights. The amount of total phenolic was higher in rhizosphere than non rhizosphere soil that determined by 0.7 to 0.9 and 0.3 to 0.57 mg/g soil respectively. The bindweeds exudates allelopathic activity could be caused by allelochemicals quantities and a vast array compounds to have remarkable metabolic feature to secreted metabolites of their roots. The analysis of exudates metabolic profile has shown 6 compounds umbelliferone (C9H6O3), querctin (C15H10O7), gentisic acid glycoside (C13H16O9), coumaric acid glycoside, vanillic glycoside (C14H18O9), ferulic glycoside characterized by LC–MS. These results interpretate the establishing of bindweeds different type of soils by their negatively effect on associated plants and microbes though underground chemical signals.

Keywords: Convolvulus arvensis, exudates, allelochemicals, phytotoxicity, microbes, rhizosphere