Abstracts |
Arbuscular mycorrhizal fungi (AMF) establishing efficient symbiosis with plants
play an important role on ecosystem sustainability and can be useful for revegetation ofdegraded
lands. Symbiotic efficiency is related to AMF genotypes and plant species, as well as to
environmental conditions that may affect the expression of symbiotic relationships. Thus, the
first step to an efficient AMF symbiosis management is to study fungal variability regarding the
efficiency with different host species. In this study root colonization and efficiency of several
AMF isolates, obtained from bauxite minespoil areas from two distinct environments (''serra'' and
''campo''), were evaluated for seedling growth of pioneer species [aroeira (Schinus
terebenthifolius) and trema (Trerna micrantha)], and secondary species [acoita-cavalo (Luehea
grandiflora) and sesbania (Sesbania virgata)], in a low fertility soil. The experiment was
carried out under greenhouse conditions, for 120 days. Each plant species, was treated with ten
AMF inoculation types (AMF isolates or their mixtures): Acaulospora longula, Paraglornus
occulturn, Glornus sp., Gigaspora sp., Acaulospora spinosa, and the mixture of all ''campo''
species; Acaulospora scrobiculata, Paraglomus occultum, Glomus sp. And the mixture of all
''serra'' species. For a comparison two additional treatments were included: one inoculated with
efficient Glornus etunicatum, as reference, and an uninoculated treatment, as control. The growth
of all plant species was lower in the absence of AMF whereas AMF inoculation enhanced plant
growth. Benefits varied according to isolates and plant species. All tested isolates or their
mixtures were efficient in sesbania, while only one Glornus sp. Was inefficient for trema and
aroeira and - both Glornus sp. Isolates were inefficient for acoita-cavalo. It was found that no
isolate from bauxite mine spoil was more efficient than Glornus etunicaturn. However, several
isolates from campo (Gigaspora sp., Paraglornus occulturn and Acaulospora spinosa) were as
efficient as G. Etunicaturn for all hosts. These results show that degraded land, i.e., bauxite
mine spoils can have efficient ''Fpopulations which may contribute to land rehabilitation. |