Allelopathic Effects of Barley Extract (Hordeum vulgare) on Sucrose Synthase Activity, Lipid Peroxidation and Antioxidant Enzymatic Activities of Hordeum spontoneum and Avena ludoviciana

During two surveys, allelopathic effects of barley (Hordeum vulgare) extract on growth, photosyn- thesis and lipid peroxidation were assessed in Hordeum spontoneum and Avena ludoviciana seedlings in Islamic Azad University, Shoushtar Branch (Iran). The experiments were carried out under completely randomized design with 6 replications and 4 treatments (foliar application of 10, 20, and 30 % barley extract solutions and water as control). Remarkable decrease was observed in photosynthesis, sucrose synthase activity, antioxidant enzymatic activities of target weed species in line with the increase in barley extract percentage. Malondialdehyde reached its top con- centration in Hordeum spontoneum and Avena ludoviciana plants (0.067 lmol/g FW) treated with 30 % barley extract solution; the lowest Shoot dry weight of Avena ludoviciana (0.58 g) and Hordeum spontoneum (0.53 g) were obtained with 30 % barley extract solution treatment. This study supported the assumption that barley extract inhibited the Hordeum spontoneum and Avena ludoviciana seedling growth through increasing lipid peroxidation.