Allelopathic Effect of Eucalyptus Extract on Antioxidative Responses of Soybean and Velvetleaf

Plants are beneficial or harmful on other plants through allelochemicals which may be directly or indirectly released from alive, dead plants and or microorganisms. The aim of this study was to investigate the allelopathic effect of leaf extract from Eucalyptus on total protein content, enzymatic and non-enzymatic antioxidant activities of soybean (Glycine max L.) and velvetleaf (Abutilion theophrasti Medicus). Treatments were leaf extracts of Eucalyptus (25%, 50%, 75%, 100% w/v) and distilled water as a control. The results of pot culture experiments showed that the extracts decreased total protein content of both plants. In spite it was increased the proline content, phenolic compounds and activities of polyphenol oxidase and peroxidase of leaves. However the level of changes was different for examined plants. Sum of data showed that the allelopathic effect of Eucalyptus extract on velvetleaf was more than soybean and the concentration 75% and 100% of extract could be more analyzed as natural herbicide.