Eucalypt is efficient at taking up Ca from the soil, however little is known about the contribution of ectomycorrhizas and organic acids to this process under field conditions. The accumulation of calcium oxalate crystals (CaOx) was evaluated in, approximately, 2,100 fine lateral roots and ectomycorrhizas of a 2.5-year-old Eucalyptus grandis x Eucalyptus urophylla hybrid, grown in a mountainous area at Viçosa, MG, Brazil. Optical and scanning electron microscopy techniques were used for CaOx observation. Abundant accumulation of calcium as druses […]

The basidiospores of Pisolithus sp. contain large amounts of lipids, indicating provision for future germination in the host rhizosphere. However, the accumulation, composition, and mobilization of lipids during formation and germination of these spores are largely unknown. In this study, lipid storage and fatty acid composition during basidiosporogenesis were analyzed in fresh basidiocarps using bright-field microscopy and gas chromatography. Abundant lipid bodies are found in the hyphae, basidia, and basidiospores of fungal basidiocarps. This evidences a considerable C transport in […]

This study was carried out in the field to evaluate root colonization of three Eucalyptus grandis x E. urophylla hybrids by mycorrhizal fungi as affected by soil conditions. Roots of three clonal trees, each five year old, were evaluated in regard to colonization by ectomycorrhizal and by arbuscular mycorrhizal fungi, in three areas of the State of Espírito Santo, Brazil, at four different times (July and October, 1992; January and April, 1993). The percentage of mycorrhizal colonization was dependent on […]