**6. Discussion**

The bryophilous Agaricomycetes have been analyzed by optical and electron microscopy, *in vitro* cultures, DNA sequencing and phylogenetic analysis in the articles published up to now. Some works highlighted other relevant characteristics, such as edibility, toxicity, and antioxidant properties. Thirty-three species from four orders of Agaricomycetes were reported growing with mosses and liverworts in Brazil. In general, the diversity of possible associations between bryophytes and Agaricomycetes of woody basidioma stands out in small species of lamellate fungi. Moreover, most studies including Brazilian bryophilic species do not approach this interaction satisfactorily, and usually the associated bryophytes are not identified, or when they are identified, it is not described how the association is really occurring.

Bryophyte-Fungi associations sometimes present mutually beneficial symbiosis with bidirectional exchange of resources between partners, i.e., to be mycorrhizal-like even in the absence of true roots in bryophytes [4]. Also, it has not been investigated

whether opportunistic parasitism of damaged or stressed bryophytes occurs [1]. In Brazil, about 1524 species of bryophytes were recorded, distributed in 117 families, divided into 11 species of hornworts, 633 liverworts, and 880 mosses [102]. These plants display a higher diversity and a greater number of species in areas of higher elevations and with less anthropic activity [102]. However, bryophytes may grow on different substrates, such as corrugated iron roofs, invertebrates, among others [16]. Among the types of substrates colonized by bryophytes there is a predominance of corticolous, followed by terricolous, rupicolous, and epixilous [102], without the mention of Fungicolous Bryophyte lifestyle.

In our study, the majority of mosses/liverworts and fungi growing together shows occurrences from high and damp places, in the Atlantic Forest, Amazonia, Caatinga, and Pampa biomes. Some species found in our revision, such as, *Rickenella fibula* and *Gerronema sphagnorum*, among others, occurs only on mosses [18, 20, 58]. Many of the identified bryophytes occur on identified fungi [16], such as of *Phellinus*, *Fuscoporia,* and *Hyphodontia.* Also, the mosses usually grew abundantly on the dead trunks on which the fungi were found [16]. Although bryophytes can colonize different environments, studies reveal that the majority of bryophyte species must have a preference for a single type of substrate [103]. The appearance of bryophytes must be influenced by several abiotic factors, as light availability, moisture, and water [102]. The fungi also need moist environments to complete their life cycle but light is not needed by all species [25].

The abiotic conditions are usually found in mountainous tropical areas, as humid climate with rains distributed throughout the year, ample variation of temperatures from the lowland to the high mountains, high rainfall, and topography, all factor enabling greater number of microhabitats [102]. Despite bryophytes can produce defense mechanisms, in response to fungi attack, with the host plant in the process of evolving mechanisms to stop the pathogen's advance [26], some studies show that some bryophyte species do not have their reproduction affected by parasitic fungi [18]. Also, associations between bryophytes and fungi can function in different ways, such as mycorrhizal, parasitic, and commensal [1]. Furthermore, they can have several benefits, both for fungi and for bryophytes, such as improvement in obtaining and cycling nitrogen, carbon (and other nutrients) and in the maintenance of more humid and protected environments [3, 4, 9, 34]. Many species of fungi associated to bryophytes are also found also in extreme environments, such as Antarctica, for example, probably indicating a symbiotic more than parasitic relationship [31, 38].

However, in Brazil these relationships Bryophyte/Agaricomycetes have not been characterized and studied and it is not known whether the occurrence of bryophytes was casual or whether a fungal association really occurred. This demonstrate the importance of more studies in this area in Brazil, what will make it possible to elucidate the ecological and physiological nature of these associations, among other issues, such as the influence of the environment on these associations.
