Allelopathic effects of extracts from wheat seedlings and its secondary metabolite DIMBOA on weeds

Chinese. 研究了小麦活体、小麦水提液及小麦次生代谢产物丁布对几种杂草的异株克生活性。小麦与马唐、反枝苋、野燕麦、早熟禾、稗草等杂草混播的盆栽试验呈现出小麦播种 密度越大,杂草种子萌发率越低的趋势。小麦水提液对马唐、反枝苋、早熟禾、稗草、野燕 麦根和茎的生长均有明显的异株克生作用，IC50(根)1.5 mg/ mL，IC50(茎) 3.0 mg/ mL，而 对黑麦草、圆叶牵牛无明显的抑制活性。除马唐外，小麦水提液对供试杂草种子萌发抑制效 果不明显。小麦次生代谢产物丁布对3种不同杂草的根、茎总体抑制效果为反枝苋马唐野 燕，IC50(根、茎) 1.5mg/ mL, IC50(种子萌发) 3.5 mg/ mL。比 较IC50可知，生物活性：丁布小麦水提液。丁布是小麦中具有异株克生活性的次生代谢物。

English. The allelopathic effects of wheat aqueous extracts and secondary metabolite DIMBOA on several weeds were studied. The results showed that intercropped with weeds, wheat had strong allelopathic effects on Digitaria sangguinalis (L.) Scop, Amaranthus retroflexus L., Echinochloa crusgalli_ (L.) Beauv., _Poa annua_ L. and _Avena fatua L.. There was a negative correlation between the germination inhibition ratio of weeds and the density of wheat seedlings. Wheat aqueous extracts had a significant allelopathic effect on weed seedlings of D. sanguinalis, P. annua , A. retroflexus, E. crusgalli and A. fatua, with IC50_(root)1.5 mg/ ml and IC50 (stem)3.0 mg/ ml. But their inhibitory effects on _Lolium multiflorum _Lam. and Pharbitis purpurea(L.) Voigt were not detected. There was no significant correlation between the concentration of the aqueous extracts and the germination inhibition ratio of the weeds, except for D. sanguinalis. The general trend of the allelopathic effects of DIMBOA on different weed species was: _A. retroflexusD. sanguinalisA. fatua, with IC50 (root, stem)1.5 mg/ ml and IC50 (seed germination)3.5 mg/ ml. As for bioactivity, DIMBOAaqueous extracts in terms of IC50. The results showed that DIMBOA, having allelopathic effects on weed growth, was the main secondary metabolite in wheat hydroponic solution.