Seed germination and seedling growth of invasive Aegilops tauschii with application of coumarin.
To determine the allelopathic inhibition of coumarin on Aegilops tauschii and the feasibility of using coumarin as a biological method for invasive plant control, the effects of coumarin with different concentrations (50, 100, 150 mg.L-1) on A. tauschii seed germination and seedling growth were evaluated in a sand-culture experiment. Results showed that compared with a control, the germination rate, germination index, growth of seedling height, and root length were inhibited with increase of coumarin solution treatment. The inhibitory effect of coumarin on the growth of root length was greater than that of seedling height based on the value of the inhibition rate. Only with the 50 mg.L-1 coumarin solution treatment did the relative conductivity and MDA content not increase significantly at 10 d compared with at 5 d (P < 0.05). With the 150 mg.L-1 coumarin solution treatment, the proline content did not increase significantly, and the superoxide dismutase (SOD) activity decreased at 15 d compared with at 10 d. The above results indicated that 150 mg.L-1 coumarin solution had a strong allelopathic and inhibitory effect on seed germination of A. tauschii and could regulate seedling growth of A. tauschii by changing antioxidant enzyme systems, cell membrane permeability, and membrane lipid peroxidation.