Inoculum production of arbuscular mycorrhizal fungi native to soils under different forest covers

Abstract

ABSTRACT The low natural fertility of Brazilian soils requires the use of inoculants that facilitate the absorption of nutrients by plants. Arbuscular mycorrhizal fungi such as obligatory biotrophics of active roots perform this function, but access to this resource is limited by the difficulty in producing inoculants. The objective of this study was to investigate the production of AMF inoculants native of soils under different forest covers in Vitória da Conquista, BA, by means of spore quantification, colonization rate and species identification. For this purpose, soils were collected from sites under Mata Nativa (native forest) and plantations of Madeira Nova (Pterogyne nitens) and Eucalyptus, placed into separate 500 mL disposable cups with seeds of Brachiaria sp. and cultivated for five months. Spores were quantified and the AMF species identified in the control soil (without brachiaria) and in the cups cultivated with brachiaria at each month. From the first month, the colonization rate of brachiaria roots was evaluated. The inoculants produced showed differences in the number of spores and species, in the AMF species identified, and in the root colonization rate as a function of the forest cover. Thus, considering the increase in the number of spores, species and colonization over time, the inoculant produced from the soil under native forest was more promising for utilization.