Phytotoxic activity of Ulex europaeus, an invasive plant on Chilean ecosystems: separation and identification of potential allelochemicals

Despite its worldwide relevance as an invasive plant, there are few studies on Ulex europaeus (gorse) and its allelopathic activity is almost unexplored. The allelochemical profile of gorse was analysed through methanolic extract of pods and roots, and its phytotoxic effects on Lactuca sativa germination. The methanolic extract of pods had no effect in germination, while extract of roots resulted in a U-shaped dose-response curve: reducing the germination at concentration 0.5 mg mL(-1). GC-MS analysis detected compounds with proven antimicrobial and antioxidant activities in the pods and cytotoxic compounds in the roots, which could explain the bioassay results. The quinolizidine alkaloids (QAs) composition was evaluated to predict possible biological functions. It showed the presence of QAs in gorse that are absent in their native range, indicating broad defense strategies against bacteria, fungi, plants, and insects in the Chilean ecosystem. This could explain the superiority of gorse in the invaded areas.

Automated summary

Despite its worldwide relevance as an invasive plant, there are few studies on the allelopathic activity of Ulex europaeus (gorse). This study analyzed the allelochemical profile of gorse and its phytotoxic effects on Lactuca sativa germination. The results showed that the methanolic extract of gorse roots inhibited seed germination at a certain concentration. The presence of antimicrobial, antioxidant, and cytotoxic compounds in gorse could explain its superiority as an invader in the Chilean ecosystem.