Fungos micorrízicos arbusculares em ecossistema de Mata Seca no norte de Minas Gerais

Abstract

This study was conducted in State Park Dry forest in the city of Manga in the North of Minas Gerais, Brazil and aimed to evaluate the occurrence and diversity of arbuscular mycorrhizal fungi (AMF) and the protein related to soil glomalin and biomass of external mycelium in Dry Forest ecosystems in the North of Minas Gerais. To collect the soil samples in each area were delimited plots of 1000 m2 with three replications for each study area. The bags were made in February 2008 in areas with different stages of succession is: area of initial eight years in the process of regeneration, intermediate with 17 years without human intervention and late registration without human intervention and an area of pasture five years without human interference, making the grass (Panicum maximum) in State Park Dry forest. Sampling was at random, taking nine composite samples consist of 27 single samples were taken at a depth of 0 - 10 cm in each study area to assess the diversity of AMF, six composite samples formed from 18 single samples of each study area for extraction and quantification of glomalin and three composite samples from nine single samples of each area of external mycelium. Were recovered 19 AMF species, belonging to the genera: Acaulospora (7), Glomus (7), Scutellospora (3), Gigaspora (1) and Archaeospora (1). The number of spores ranged from 37 to 640/50 cm3 of soil. The biomass of external mycelium is not statistically different between the four areas studied, but there is a growing trend in the pasture area toward the area of late succession. For the protein related to soil glomalin, the area of pasture had a higher amount of easily extractable glomalin, while the total glomalin was statistically equal between the four areas. The area with the initial sequence showed the greatest number of species (12). Were found in all areas A. scrobiculata, G. macrocarpum and G. tortuosum. The genus Glomus showed a higher percentage of occurrence in all areas studied. The area of intermediate succession, and the late without anthropogenic interference had lower densities and number of spores compared to the other areas studied indicating systems are more stable than other areas.