Main Article Content
Allelopathic compounds are secondary metabolites which are produced during different metabolic pathways and apparently they have no prominent role in plants’ growth and development. However, these compounds are supposed to play an important role in defense and interactions of producers with receivers. In this study, aqueous and methanolic leaf extracts of Populus nigra were screened for the presence of secondary metabolites and tested for the allelopathic effects on seed germination of four wheat cultivars (Ghazanvi, Siran, Atta Habib and Janbaz). Phytochemical screening revealed the presence of alkaloids, flavonoids, steroids, terpenoids, saponins, tannins, phlobatanins, and glycoside, reducing sugars, triterpenes, phytosterols and proteins in leaf extracts. Allelopathic bioassay demonstrated that leaf extracts had detrimental influence on the seed germination of four cultivars of wheat, which depended on the amount of powder dissolved in extracts (10, 20, 40 and 80 g). Methanolic extracts exhibited greater degree of phytotoxicity than aqueous leaf extracts. Among the tested cultivars, Janbaz and Ghaznavi were more sensitive to aqueous and methanolic extracts particularly at the highest dose of concentration (80 g). The study suggests the presence of wide range of bioactive compounds in P. nigra leaves with phytotoxic potentials on wheat germination.
Keywords: Allelopathy; Alkaloids; Inhibitory effect; Secondary metabolites; Wheat