This paper aims to highlight the direct and indirect allelopathic influences showed by species Ailanthus altissima, through morphological and biological investigations. An important factor in the success of Ailanthus species invasion is the release of allelopathic compounds that influence negatively the vegetation in habitats where it installs. Recent studies show that interactions between invasive species and native species based on allelopathy may be one of the mechanisms underlying the remarkable success of some of the most aggressive invasive plants. Ailanthus contains toxic allelopathic compounds to many woody and herbaceous plants, toxic compound called ailantona, identified and classified as the most effective phytotoxic component. Several studies have shown that extracts of Ailanthus inhibit germination and growth of several species of angiosperm and gymnosperm plants, in biotests and greenhouse experiments. Our studies included a laboratory experience in which we studied the germination of seeds treated with extracts obtained from Ailanthus species and behaviour of species under the influence of the same extracts treated containing allelopathic compounds. Based on research conducted in the laboratory, by studying the degree of externalization of the main morphological features, as well as by determining the influence of the allelopathtic compounds present in the Ailanthus altissima on leguminous species studied, it was revealed that seed germination of the Sinapis alba and Brassica napus was inhibited by extracts containing allelopathic substances, regardless of the concentration they have been treated with. Also, extracts negatively influenced the growth of seedlings treated. Experiments carried out demonstrate that the allelopathtic potential of the species is very powerful and can influence negatively the neighbouring species. Given the current climate, the species Ailanthus altissima is favoured over native species. This fact combined with the allelopathtic effects demonstrated also by experiments carried out in the current paper may lead to future expansion of this species with major impacts on biodiversity.

Ailanthus altissima, allelopathy, germination, leguminous species

Presentation: oral