Mutual allelopathic effect between invasive plant Aegilops tauschii and wheat.
The Aegilops tauschii Coss. is a worldwide invasion weed. The competitions between A. tauschii and native species not only caused serious influence on ecosystem structure and succession, moreover, it poses a greater threat to the safety of food production. There was a significant interaction allelopathic between A. tauschii and wheat, and the allelopathic inhibition of A. tauschii on the seed germination of wheat is stronger than the effect of wheat on the A. tauschii. Both A. tauschii and wheat have allelopathic on each other seedling growth, and it is expressed as promotion at low concentrations but inhibitory at high concentrations on the growth of seedling height and root length. On the one hand, adaptation of wheat or A. tauschii seedlings to the allelopathic stress from the other depends on a constant increased in proline content and SOD activity. On the other hand, allelopathic stress can destroyed the cell membrane structures and disrupt the function of seedlings, aggravate membrane lipid peroxidation, and increased both the relative electrical conductivity and MDA content. The synthetic allelopathic effect showed that, at 10-100 mg mL-1 concentrations, the aqueous extracts of A. tauschii stem and leaves had higher allelopathic inhibitory effects on wheat seedlings than the aqueous extracts of roots. At 25-100 mg mL-1, the aqueous extracts of wheat had similar allelopathic inhibitory effects on A. tauschii seedlings. In summary, the strong allelopathic inhibition of A. tauschii on the seed germination and seedling growth of wheat may be the important reason for its large-scale invasion in wheat field.