Lecanoromycetes

Cladonia sp.

The Lecanoromycetes are a class of Ascomycota. With approximately 13,500 species, they are the most species-rich fungal class. It includes most of the lichen -forming fungi.

Features

The majority of the species forms apothecische fruiting bodies. Some families ( Porinaceae, Thelenellaceae and relatives ) also form perithecische fruiting bodies. The asci are usually bitunicat, although the structure is different than in the other classes bitunicate. Often, the asci are complex, but sometimes prototunicat ( Caliciaceae ), or unitunicat ( Porinaceae, Coenogoniaceae ). The opening mechanism of the asci is rostrat, semifissitunicat or bilabiat in most species. The ascus walls and the thickened tip stain blue with iodine. The ascospores are one or more times septate, rarely pluriloculär, and hyaline or pigmented. There are sometimes over 100 spores per ascus formed this feature, however, has evolved several times independently within the class.

The paraphyses are simple or branched, and often swollen at the tip. The hymenium is often gel-like.

The Lecanoromycetes form a wide range of secondary ingredients; these include polyketide derivatives ( such as depsides, depsidones, anthraquinones and xanthones ), terpenes and Pulvinsäure derivatives.

The side fruit shapes ( Anamorphic ), if known, form pycnidia.

Way of life

The majority of the species usually forms with different green algal lichens. As photobionts Chlorococcales come ( the most common genera are Asterochloris, Coccomyxa, Dictyochloropsis, Trebouxia ), filamentous green algae ( Trentepohlia, Pycopeltis ) and cyanobacteria ( Calothrix, Nostoc, Scytonema, Stigonema ) ago. In some lichens, particularly common in the order Peltigerales, cyanobacteria are found as secondary photobiont before next green algae. The class consists of about 90 percent of all lichen -forming fungi.

Some species grow on other lichens ( lichenicol ), some live as Saprobiont.

System

The Lecanoromycetes are closely related to the Eurotiomycetes. Whether they are the sister group is not yet clear.

The internal classification of this species-rich group is still in flux. The two subclasses Acarosporomycetidae and Ostropomycetidae are most likely natural affinity groups, ie monophyletic taxa. The extent of the largest subclass, Lecanoromycetidae is not yet fully understood. Hibbett et al. (2007) divided the class as follows:

  • Subclass Acarosporomycetidae Order Acarosporales with single family Acarosporaceae

The systematics of the Lecanoromycetes has changed since the beginning of the DNA sequence analyzes in relation to the phenotypic characteristics, especially the opening areas of the asci -based system very strong.

Miadlikowska et al. have the following, preliminary cladogram created in which especially the position of the Candelariales and Umbilicariales is uncertain.

Candelariales

Ostropomycetidae

Umbilicariales

Lecanoromycetidae

Acarosporomycetidae

Opisthokont Dikarya Pezizomycotina Digital Object Identifier
504344
de