Comparative evaluation of the allelopathic interference of inside and peripheral extracts of Eugenia florida DC leaves on the primary development, mitotic index and chromosomal abnormalities of Lactuca sativa L.

The chemical characterization of the species Eugenia florida identified compounds with diverse beneficial pharmacological potential, making it a target for extensive research. The aim of this study was to investigate the phytotoxic and cytogenotoxic effects attributed to exposure to E. florida, leaf extracts obtained from different positions in the canopy (inside and periphery) and through aqueous and hydroethanolic extraction methods. Bioassays were conducted using Lactuca sativa L. measuring parameters such as germination percentage on days 4 and 7, germination speed index, shoot length, root elongation, percentage of abnormal seedlings, and cytogenetic parameters (mitotic index and frequency of chromosomal abnormalities). The results demonstrated that different leaf extracts of E. florida displayed no variation in phytochemical composition, with the presence of flavonoids, phenols, tannins, catechin, saponins, and terpenes. However, the collection position and extraction method have a significant impact on the allelopathic potential of the different extracts. Peripheral leaves, when subjected to hydroethanolic extraction, demonstrated greater efficiency, showing phytotoxic effects on root elongation and morphological abnormalities. Furthermore, a mitodepressive effect greater than 50% was observed, without the detection of genotoxic damage. Thus, this study provides the first evidence that E. florida extracts possess allelopathic potential, especially in the post-emergence phase in bioassays with L. sativa, inducing morphological and cytotoxic alterations. These results highlight the feasibility of using these extracts and pave the way for future research, contributing to the development of more ecological alternatives in agriculture.