Acta Botânica Brasílica (Dec 2012)
Diversidade de fungos micorrízicos arbusculares em área de Caatinga, PE, Brasil Diversity of arbuscular mycorrizal fungi in an area of Caatinga, PE, Brazil
Abstract
O objetivo deste trabalho foi o de determinar a infectividade, a riqueza de FMA e a condição micorrízica da vegetação em área de Caatinga não antropizada. Coleta de solo e raízes foi realizada em Triunfo/PE. Raízes foram examinadas para determinação da colonização micorrízica. O número mais provável (NMP) de propágulos infectivos de FMA foi estimado por diluições sucessivas do solo e a utilização de milho (Zea mays L.) como planta isca. Glomerosporos foram quantificados e preparados em lâminas, para identificação das espécies. As plantas apresentaram-se pouco colonizadas (média The objective of this work was to determine the infectivity and richness of AMF and the mycorrhizal conditions of the vegetation in a preserved area of Caatinga. Soil and root samples were taken in two subareas in the municipality of Triunfo, PE. The roots were stained with Trypan blue, and observed with a microscope to determine if colonization of mycorrhizal fungi was present. Glomerospores were extracted from soil, counted, mounted on microscope slides and the AMF species were identified. The plants from the area showed < 10% colonization. The number of glomerospores (<1 g-1 soil) did not differ between the subareas although in one area the amount of P in the soil was three times higher than in the other. The number of AMF propagules varied from 64 to 70 cm-3 in the soil. Sixteen taxa of AMF were registered and Glomus was the most representative genus, with seven species. Pacispora boliviana is reported for the first time in Brazil. The high amount of P probably contributes to the low values of propagules, colonization, infectivity and richness of AMF in the area. AMF have been commonly found in the Brazilian semiarid region and species of Glomus are predominant in this environment.
