Eureka! Institutional Repository

The present study aimed to investigate the effect of soil salinity on the barley allelopathic potential. For this purpose, 18 barley varieties (Athenaida, Triptolemos, Galt Brea ΄S΄, ICB 100126, Orgei/EH 165/Cross 270.2.3, Ippolytos, Vyzantiο, Prestige, Scarlet, Meteor, Matico ΄S΄/LB Iran A-164, Tomillo ΄S΄/DS4931 A-172, Europa, Robur/WA 2196-68, Robur/J-126/OWB, 80.5060/Gloria ΄S΄ A-196, Franka/6/Mona/Nopal ΄S΄ A-242 and 4259/CI5831/Estate A-69) were cultivated simultaneously in saline and non-saline soil. The allelopathic potential of these varieties was evaluated in aboveground samples taken during the spring period, using the Perlitebioassay with the weed rigid ryegrass (Lolium rigidum) as plant indicator. In particular, the effect of the concentration of water extracts of barley varieties on germination and the root growth was evaluated. In addition, germination or root length inhibition indices were calculated using the WESIA (Whole-Range Evaluation of the Strength of Inhibition in Allelo- pathic-Bioassay) program. The two main barley-allelopathic substances (gramine and hordenine) were determined by the liquid chromatography method. The results of the bioassays showed that the increase in the concentration of the extracts caused an increase in the germination and root length reduction. In most cases, the concentration of 5% caused 100% inhibition of germination and root length. The extracts of 14 varieties grown on saline soil caused lower reduction in the germonation and root length of the indicator plant than the corresponding plant extracts grown on non-saline soil. In contrast, for the remaining 4 varieties, extracts from saline and non-saline soil caused similar reduction of the germination and root length of rigid ryegrass. In most cases, concentrations of gramine and hordenine were less in the extracts of plants grown on saline soil than the corresponding plant extracts grown on non-saline soil. In conclusion, soil salinity has adversely affected the allelopathic ability of most barley varieties.