effects of allelopathic compounds of barley (hordeum vulgare l.) on seed germination, seedling growth and some antioxidant activities of chenopodium album l.

in this study, phytotoxicity of allelochemical barley (hordeum vulgare) extracts on chenopodiom album germination and enzymes activities were bioassay. allelopathic extracts were a phenolic and three alkaloids compounds (strychnine, atropine and quinine). experiment was carried out under completely randomized design with three replications. results indicated that the alkaloids atropine and strychnine had the highest negative impact on germination percentage, germination rate, seeding fresh weight, activities of catalase, proxidase and alpha amylase enzymes. also, these treatments caused to increase cell membrane’s damage and malondialdehyde (mda) concentration in the tissue of target weed. the highest concentration of mda of chenopodiom album was belonged to strychnine treatment with 0.076 nmol.g-1 fresh weight of seedling. the highest activity of catalase, proxidas (6.3 and 17.1 mg observed in 60 seconds, respectively) and alpha amylase (9 nmol of seeds per minute) was observed in quinine next to control treatment, suggesting low impact of this alkaloid in purposed plant, compared to other allelochemicals. generally, barley allelochemical extracts including phenolic, strychnine and atropine compounds had higher negative effects on seed germination and enzymes activities of chenopodiom album seedling.