Fungos micorrízicos arbusculares em campos de murundus após a conversão para sistemas agrícolas no cerrado

Abstract

The murundu fields (Campos de Murundus) are characterized by mounds occurring in some parts of the Cerrado (Brazilian tropical savanna) biome with important ecological functions for the maintenance of soil sustainability. Conversion to agricultural systems may lead to changes in physical, chemical, and biological soil properties not yet assessed, such as reduction in the biodiversity of arbuscular mycorrhizal fungi. The aim of this study was to evaluate how the conversion of mound fields into agricultural areas changes the community of arbuscular mycorrhizal fungi (AMF). Treatments consisted of three agricultural areas subjected to the same agricultural management and use in a chronosequence (seven, 11, and 14 years) and two in the mound fields, sampling at the top (TM) and between the mounds (EM)). AMF spores were extracted and counted, and AMF species were identified by morphological characteristics. The total AMF recovered was 27 species, made up of nine species of the Acaulosporaceae family, one Ambisporaceae, seven Glomeraceae, two Claroideoglomeraceae, and eight Gigasporaceae. Of this total, the species Acaulospora scrobiculata, Glomus macrocarpum, and Gigaspora sp occurred in all areas in the two years studied. The species Acaulospora mellea, Acaulospora cavernata, Acaulospora colombiana, Glomus diaphanum, Scutellospora reticulata, and Scutellospora sp only occurred in the mound fields. The conversion of mound fields into an agricultural area modified the occurrence and composition of the arbuscular mycorrhizal fungi community, and the species Acaulospora scrobiculata, Glomus macrocarpum, Gigaspora sp, and Claroideoglomus etunicatus occurred in all areas. The non-occurrence of some species in the crop areas, such as the species Acaulospora cavernata, Acaulospora columbiana, Rhizophagus diaphanus, Scutellospora reticulata, and Scutellospora sp, represents a loss of diversity of these fungi. Therefore, this study is the first report of the occurrence and community structure of AMF in the mound field vegetation type. It contributes to better understanding of AMF in the Cerrado biome and shows that the changes introduced by conversion of the area alter the occurrence and diversity of arbuscular mycorrhizal fungi