Abstract

The root, stem and leaf aqueous extracts of Paeonia decomposita were assayed at 0.025, 0.050, 0.075 and 0.1 g ml^-1 for their seed germination and early seedling growth of wheat. All aqueous extracts at all concentrations inhibited seed germination and seedling growth of wheat compared with the control, and the degree of inhibition increased with the incremental extracts concentration. Protective enzymes unfolded different trends with increasing concentrations of aqueous extracts. Compared to the control, superoxide dismutase (SOD) and polyphenol oxidase (PPO) activity increased at first but then dropped with increasing concentrations of root extracts, but increased with increasing concentrations of stem extracts. Catalase (CAT) activity increased with increasing concentrations of all the aqueous extracts. It was concluded that P. decomposita extracts, especially in root, have significant herbicidal effects on the germination and growth of wheat, and the mechanisms of antioxidative enzymes under allelopathic effects of P. decomposita on wheat are not yet clear.

Key words: Paeonia decomposita Hand.-Mazz., allelopathic effects, wheat, protective enzyme.