Genetic diversity of Egeria densa Planch. (Hydrocharitaceae) in Brazilian reservoirs

Macrophytes harbor numerous potentially invasive species that pose a threat to biodiversity and ecosystem services in freshwater environments. Egeria densa (Hydrocharitaceae) stands out as a prominent invasive species, recognized as a significant global invader across various ecosystems. In this study, we conducted an assessment of the genetic variability of this species in four Brazilian reservoirs, which are part of the species’ native range, employing the internal transcribed spacer (ITS) from the nuclear marker and the intergenic chloroplast marker trnL-trnF. The obtained sequences were then compared with those available in GenBank (NCBI). The results of our investigation revealed a low genetic differentiation among the sampled populations. For ITS and trnL-trnF, we identified four and three distinct haplotypes, respectively, with a predominant single haplotype shared by most specimens. Notably, we did not observe a discernible phylogeographic structure. The data we obtained represents the first sequences of E. densa within its native habitat, providing valuable insights on its genetic diversity and helping to understand invasive processes.