Phytotoxicity and allelopathic potential of Croton urucurana Baillon: impacts on seeds germination and seedlings development of target plants

Allelopathy is a biological event in which organisms affect the growth and development of other species through the release of secondary metabolites termed allelochemicals. Croton species are known for their rich production of these metabolites, which present bioactive potential and allelopathic potential. Croton urucurana Baillon is a plant that has been traditionally used in folk medicine for its pharmaceutical properties, although this plant presents phytoconstituents that exhibit allelopathic properties, which have been poorly explored. Thus, this study (1) aimed to identify the phytoconstituents and measure allelopathic activity of aqueous and hydroethanolic extracts of C. urucurana Baillon and (2) to determine influence of these phytocompounds on seed germination and initial growth of Lactuca sativa L. Triticum aestivum L. coleoptile growth and genotoxicity utilizing Allium cepa L. Data demonstrated the presence of several compounds, predominantly quercetin, kaempferol, and apigenin derivatives. These compounds may be responsible for C. urucurana- initiated inhibitory effects on seed germination and early development of L. sativa and wheat coleoptiles growth. Further, the secondary metabolites may have interfered with roots cells of A. cepa reducing mitotic index, increasing number of chromosomal aberrations, and inducing micronuclei formation, which indicate the genotoxic potential of extracts from C. urucurana. Therefore, this specie from Croton genus appears to be a promising source of natural allelochemicals that might be used for both sustainable management of invasive plants and environmental toxicity assessment studies.