Allelopathic Effect of Licorice (Glycyrrhiza glabra L.) Extract on Germination Properties and Enzymes Activity in Bread Wheat (Triticum aestivum L.) and Chickpea (Cicer arietinum L.)

In order to investigate allelopathic effects of aqueous licorice leaf and root extract on germination properties and some enzymes activity of wheat and chickpea seedlings, a factorial experiment based on completely randomized design with 3 replications was conducted out in Shahid Bahonar University of Kerman laboratory in 2017. Treatments were leaf and root extracts of licorice (25%, 50%, 75% w/v) and distilled water as a control. Increasing leaf extracts concentration caused the greatest reduction in germination percentage and rate (97.2% and 97.3%) of wheat, and root and stem length (92.2% and 67.8%) of chickpea. Meanwhile, increasing root extracts concentration caused the greatest reduction in germination percentage and rate (56.6% and 74.8%) of wheat, and root and stem length (93.6% and 66.7%) in chickpea. Although the malondialdehyde concentrations of wheat and chickpea seedlings were significantly increased (66.3% and 24.2% in wheat and chickpea affected with leaf extract, and 63.1% and 15.8% in wheat and chickpea affected with root extract, respectively), wheat seedling showed higher sensitivity. Catalase activity showed significant decrease in treatments (91% and 46% in wheat and chickpea affected with leaf extract, and 95% and 54% in wheat and chickpea affected with root extract, respectively). This enzyme activity showed more decline in wheat than chickpea. These results also indicated that the leaves aqueous extract has more allelopathic inhibitory effects than the roots.