Taxonomia de fungos gasteroides (Basidiomycota) em áreas de caatinga do Rio Grande do Norte e Paraíba, Brasil

Abstract

It is estimated that there are about 3.8 million species of fungi, of which about 120,000 have been described to date. Gasteroid fungi currently represent a polyphyletic group with about 10,000 species, of which 324 species are known and described for Brazil. Since ancient times, the gasteroid fungi have demonstrated important value, being used by the humanity for diverse purposes, like economic, medicinal and gastronomic. The Caatinga, the focus of this research, has been described as a species poor ecosystem with low level of endemism. However, recent studies have challenged this point of view and demonstrated the importance of the Caatinga for the conservation of Brazilian biodiversity. In this context, the present study aimed to increase the knowledge about gasteroid fungi in two areas of biological importance in the Caatinga phytogeographic domain, in the states of Rio Grande do Norte (Serra do Torreão - João Câmara) and Paraíba (Serra de Cuité - Cuité). For this, 12 field trips were carried out in the periods with the highest rainfall incidence (February to July 2017 and March to April 2018). The collection methodology was based in specialized literature for the group. The collected basidiomas were taken to the Fungal Biology Laboratory of the Federal University of Rio Grande do Norte (UFRN), where the herborization and study of the specimens were carried out following traditional methodology for the gasteroid fungi. Scanning electron microscopy (SEM) in species requiring greater morphological detail was done. Nineteen spp. were identified distributed in eight genera: Bovista (2 spp.), Calvatia (5 spp.), Cyathus (2 spp.), Disciseda (2 spp.), Geastrum (2 spp.), Podaxis (1 sp.), Sphaerobolus (1 sp.) and Tulostoma (4 spp.). Among, five are new species for science, four are first records for South America, ten first records for Brazil, thirteen first records for the semiarid, three first records for the state of Paraíba and thirteen first records for Rio Grande do Norte. The Serra do Torreão and the Serra de Cuité have been shown to be favorable for studies about gasteroid fungi. Thus, additional taxonomic studies are necessary in areas of Caatinga, allowing an increase in the conservation of these species.