Cianobacterias en Stereocaulon (Ascomycetes liquenizados), un estudio de especificidad

Abstract

The genus Stereocaulon is a genus of tripartite lichens, that is, its thallus contains three main partners, a mycobiont and two photobionts, one algal and the other a cyanobacterium. This genus, with a wide distribution, is represented in the Colombian territory with at least 22 species. The study of phylogenetic relationships with cyanobacteria in the species of the genus Stereocaulon in Colombia could help to recognize the phenomenon of lichenization and the acquisition of cyanobacteria in tripartite lichens. The aim of this study was therefore to recognize the interrelationships of some species of the genus Stereocaulon with their cyanobacterial photobionts in several Colombian paramunal complexes. Representative species of the genus Stereocaulon were selected, sequences of the ITS marker were generated for the fungal component, and sequences of the 16S ribosomal DNA markers and of the Rubisco rbcLx region for the cyanobacteria. An opportunistic association of cyanobacteria with Stereocaulon species was found. It can be concluded that there is no close specificity between cyanobiont and mycobiont in the Stereocaulon species studied here. However, a relationship between the distribution area and the presence of cyanobacterial genera was evidenced. On the other hand, information on the genus Stereocaulon was enriched with the addition of Colombian lichen sequences to the GenBank library.