Germination and initial development of forest species under the action of catechin, presents in seeds of Sesbania virgata (Cav.) Pers. (Fabaceae)

Abstract

Sesbania virgata is a shrub that occurs in riparian forests, especially in Cerrado and Atlantic Forest. It is considered superdominant due to its rapid growth and high soil cover. Its seeds release allelochemicals during imbibition, affecting the germination and initial growth of other species. The aim of this study was to evaluate the phytotoxic effect of compounds found in S. virgata seeds on co-occurrent species from different successional stages. The species were co-germinated with S. virgata seeds and irrigated with S. virgata integument extracts, in laboratory, greenhouse, and field. The germination rate, germination speed, germination speed index, and seedling growth of the species were evaluated. Phytochemicals released by S. virgata seeds were not able to inhibit the germination of the co-occurrent forest species in field, but significantly reduced their initial growth. The results suggest that resistance to allelochemicals is not linked to the successional stage of a species but is determined by specific characteristics that guarantee the ability to tolerate the phytotoxins released by the seeds of S. virgata. In addition, the results also suggest that catechin and other compounds found in seeds may be responsible for the inhibitory potential of S. virgata plants.