Influence of Serjania lethalis A. St.-Hil. (Sapindaceae) leaf and stem crude extracts on diaspores and seedlings of different cultivated species

• Diaspores and seedlings of radish and sesame were more affected by the leaf extract of Serjania lethalis, while wheat was more affected by the stem extract.
• The extracts reduced the average size of the metaxylem cells of the sesame roots by more than 50%.
• The target species responded differently to the extracts.
• Serjania lethalis can inhibit the germination and growth of other plants in the environment; this provides a competitive advantage to the species and consequently contributes to its dominance.

Serjania lethalis A. St.-Hil. (Sapindaceae) is an abundant liana in cerrado areas and, due to its habit and distribution, is a species that interferes with the growth of other tree and shrub species. To increase our knowledge about the dominance strategies of this species, the aim of this study was to evaluate and quantify the phytotoxic potential of different organs of S. lethalis. The effects of the leaf and stem aqueous extracts were evaluated on diaspore germination and seedling growth of sesame (Sesamum indicum L.), radish (Raphanus sativus L.), and wheat (Triticum aestivum L.). The aqueous extracts were prepared in a proportion of 100 g plant material dissolved in 1000 ml of distilled water, resulting in 10% maceration. Dilutions were performed with distilled water to 7.5, 5.0, and 2.5% of the original extract concentration. The diaspores and seedlings of radish and sesame were more affected by the leaf extract, while wheat was more affected by the stem extract. The main anomalies were observed in the root system of the target species, and the extracts reduced the average size of the metaxylem cells of the sesame roots by more than 50%. The target species responded differently to the extracts, and the eudicotyledonous species (radish and sesame) were more sensitive than the monocotyledonous species (wheat) for all variables analyzed, except for the shoots of wheat seedlings, in which the largest reductions in growth were recorded. Therefore, S. lethalis can inhibit the germination and growth of other plants in the environment; this provides a competitive advantage to the species and consequently contributes to its dominance.