Reproductive system of Epidendrum purpureum (Orchidaceae), a species potentially generated by hybridization

Resumo

The study of hybridization is essential for understanding the emergence of new species and the origin of reproductive barriers that will contribute to this process. In this study, we investigated the mechanisms of reproductive isolation among three sympatric species of orchids of the genus Epidendrum, E. denticulatum, E. orchidiflorum and E. purpureum, the latter being a potential hybrid. Experimental crosses were performed to examine which forces maintain the integrity of these species. The results indicate high levels of fertility in intraspecific crosses in both E. denticulatum and E. orchidiflorum, which are the putative parental species. On the other hand, E. purpureum show significant lower levels of fertility when compared to the parental species. However, our results suggest that E. purpureum is able to reproduce on intraspecific crosses, suggesting an event of speciation by hybridization.