Didymium azorellae, a new myxomycete from cushion plants of cold arid areas of South America

ABSTRACT

A new species of Didymium (Myxomycetes), D. azorellae, isolated from plant debris in a moist chamber, collected during studies of cold arid areas of Argentina and Peru, is described. It can be distinguished by its small size, the tightly packed layer of lime crystals on the peridium, the very scant, or absent, capillitium, and the unique spore ornamentation, especially by scanning electron microscopy. The species developed on dead leaves of cushion plants growing in the extremely harsh environments of the central Andean puna at almost 5000 m elevation and the Andino-Patagonian steppe. Morphology was examined with scanning electron microscopy and light microscopy, and micrographs of relevant details are included here. In order to confirm the identity of the new species described in this paper, a molecular study was conducted based on partial sequences of both the 18S rRNA and the elongation factor 1-alpha gene. Phylogenetic analysis including two specimens from different countries of the newly described species, Didymium azorellae, strongly supports the grouping of these specimens as a separate clade from the rest of the analyzed species.

KEYWORDS:

• Amoebozoa
• Azorella
• EF-1α
• Neotropics
• phylogeny
• scanning electron microscope
• taxonomy
• xerophiles
• 18S rRNA gene
• 1 new taxon

ACKNOWLEDGMENTS

We are grateful to Italo Treviño and Laura Lorenzo for their help on the ground in Peru and Argentina, Carlos de Mier (RJB) for help with the light micrographs, Yolanda Ruiz (RJB) for technical assistance with SEM, and Joaquina María García-Martín for her help with the molecular analyses. Peruvian field work and collections were authorized by collecting and/or exportation permit no. 118-2016-SERFOR-DGGSPFFS from the Dirección General de Gestión Sostenible del Patrimonio Forestal y de Fauna Silvestre y la Dirección General del Servicio Forestal, Perú.

Additional information

Funding

This work was supported by the Government of Spain (project CGL2014-52584P) and PhD research grant (BES-2015-072763) to García-Cunchillos.