The feces of mara (Dolichotis patagonum, Caviidae, Rodentia) as dispersion agents of arbuscular mycorrhizal fungi and dark septate endophytes in the National Park Sierra de Las Quijadas, San Luis (Argentina)

LUGO M. A.; GATICA, A. ; M.S. RIVERO MEGA; E. M. CRESPO; IRIARTE, H. J.

San Luis

Congreso; XIII Congreso Argentino de Microbiología General (SAMIGE); 2018

SAMIGE-UNSL

In the diet of small mammals, the consumption of fungi is well documented in the Northern Hemisphere, Tropics and Australia. The fungi that are consumed by mammals can be epigeous or hypogeous, and are representatives of Ascomycota, Basidiomycota and arbuscular-mycorrhizal-fungi (AMF). In general, mammals eat the fungal fruiting bodies, digesting and assimilating them, except for the spores that pass through the digestive tract of the animals and are dispersed without degraded. In the world, the dispersal of spores of fungi by small mammals has been widely studied and has a close and important relationship with the ecology of forests and ecosystems where mycorrhizal associations predominate. Arbuscular-mycorrhizal-fungi are a group of biotrophic fungi that establish arbuscular mycorrhizal symbioses in the roots of most plants. These fungi contribute to the mineral nutrition of their hosts and to the conservation of the soil, among some of their functions of great ecosystemic importance. The dark septate endophytes (DSE) are a heterogeneous group of fungi belonging to Ascomycota, Basidiomycota that also establish endosymbiosis in the roots. There is global and local evidence of the role of rodents in the dispersal of fungal spores. Mara (Dolichotis patagonum, Caviidae, Rodentia) is an endemic rodent from Argentina; its diet consists of 70% of monocotyledons and 30% of forbs, with grasses as the herbaceous species with the greatest presence and relative coverage, preferring Pappophorum, Chloris, and Trichloris among the Poaceae, although mara consumes another C3 and C4 species. The grasses C3 and C4 form symbiosis with the AMF and DSE. The studied mara populations inhabit Sierra de las Quijadas National Park, San Luis (Argentina). The objective of this work was to detect the AMF and DSE in feces of D. patagonum and if mara is a potential disperser of AMF and DSE. For this, the feces of mara collected in two areas of the Park ("Jarillal" and "Sierras") were analyzed microscopically to determine the presence of AMF and DSE and trap plants were cultivated with the feces as a source of inoculum for these fungi. In mara feces the presence of AMF and DSE was scarce, and roots were also detected; further, the roots of the trap plants were colonized by AMF and DSE. We concluded that mara contributes to the dispersion of AMF and DSE, although in a meager way. Considering that mara prefers C4 grasses and that these are obligate mycotrophic host of AMF and are associated also with DSE, the remains of the ingested roots containing these fungi, the spores of the AMF and the anamorphic fructification bodies of the DSE in the feces, are the fungal structures that make up the dispersed inoculum. The presence of sporocarps of AMF and DSE in the diet of mara in the Park is reported for the first time; confirming with their presence the field observations of the consumption of soil and roots by this endemic rodent.