Establishment and infective capacity of Gigaspora margarita and Glomus clarum soil

The processes of recovering degraded lands may be benefited by the inoculation of selected arbuscular mycorrhizal fungi (AMF), for effectivety and competitiveness. Two greenhouse experiments were carried out, with the aim of evaluating the establishment and infective capacity (IC) of introduced fungi in relation to community of autochthonous fungi (AF). In the first study, 10 plant species were cultivated (three grasses and seven legumes) with three inoculum treatments [control; G margarita (CNPAB 001); G clarum (CNPAB 005)]. In the second study, the IC of the AMF was evaluated in the soil after the first experiment in bioassays, with trap plants transplanted weekly to pots containing autoclaved soil. The establishment and IC of AMF were based on the presence of spores after harvest. The introduction of AMF and the plant species influenced the sporulation of AF (Acaitlospora rugosa, Entrophospora colombiana, Gigaspora margarita and Glomus macrocarpum) in a differentiated way. The inoculation made the establishment of the inoculated fungus in all tested plants possible. However, only G. clarum presented IC to compete with the autochthonous fungi. The IC of these isolates showed no relationship to number of spores. The production of commercial inoculum using these fungi is discussed.

Glomales; endomycorrhiza; spores; degraded land; inoculation; competitiveness