Effects of leaf extracts of Amorpha fruticosa on seed germination and seedling growth of Amygdalus pedunculata

Abstract

Amorpha fruticosa and Amygdalus pedunculata are common plant species used for greening construction in arid and semi-arid region of Northwest China. In order to explore the feasibility of greening construction and ecological restoration by A. fruticose with A. pedunculata, we exami-ned the allelopathic effects of five concentrations of aqueous leaf extracts of A. fruticosa (0.025, 0.05, 0.10, 0.15 and 0.20 g·mL-1) on eight A. pedunculata varieties (YY1, YY3, YY4, YY5, YY6, SM6, SM7 and SM8), using the methods of paper-petri dish and soilless culture. The results showed that when the concentration of A. fruticosa leaf extracts were 0.025 and 0.05 g·mL-1, the seed germination and seedling growth of YY1 and SM6 were significantly better than other varieties. With increasing concentration of A. fruticosa leaf extracts, the catalase activity of A. pedunculata seedlings first increased and then decreased. The activities of peroxidase and superoxide dismutase, and the contents of soluble protein and chlorophyll showed a downward trend, while the contents of malondialdehyde and soluble sugar and the permeability of cell membrane gradually increased. Results of the principal component and cluster analysis showed that the growth potential of A. pedunculata decreased with the order of YY1, SM6, SM8, SM7, YY6, YY3, YY5 and YY4 under the allelopathic effect of A. fruticose. In conclusion, the artificial collocation and mixed planting of low-density of A. fruticosa with YY1 and SM6 were beneficial to seed germination and seedling growth of A. pedunculata.