Lineu Trindade Leal

Comportamento de Peltophorum dubium (Spreng.) Taub., Parapiptadenia rigida (Benth.) Brenan e Enterolobium contortisiliquum (Vell.) Morong cultivadas em solo contaminado com cobre

Soils contaminated by copper may interfere with the physiological development and establishment of plants. An alternative for the revegetation of these soils is the use of native species tolerant to copper. This study aimed to evaluate the tolerance of three native forest species to excess copper in the soil. The species used were: angico - Peltophorum dubium , canafistula - P. rigida and timbauva - Enterolobium contortisiliquum . The experiment was completely randomized in a 3 x 5 schedule, with three tree species and five doses of copper (0, 64, 128, 192 and 256 mg kg-1 soil) with six replicates. Plant height, shoot dry weight, length and specific root surface area and copper content in shoots and roots were determined. Canafistula and timbauva species showed storage of copper in roots and low translocation to the shoot. The shoot dry weight of timbauva and canafistula increased with small doses of copper while the shoot dry mass of angico was not affected by the doses tested. The timbauva and angico showed greater capacity for tolerance to copper contamination in the soil than did canafistula.

Efeito do cobre na população de bactérias e fungos do solo, na associação micorrízica e no cultivo de mudas de Eucalyptus grandis W. Hill ex Maiden, Pinus elliottii Engelm e Peltophorum dubium (Sprengel) Taubert

Copper is a heavy metal that can have toxic effects on microorganisms and plants. Ectomycorrhizal fungi are able to protect the plant from heavy metal toxicity, but the presence of certain metal concentrations can inhibit the growth of this fungus, damage the mycorrhizal symbiosis and also altering the development of the plants. The aim of this study was to evaluate the effect of copper on soil bacteria and fungus population, as well as the effects on the ectomycorrhizal association in the development of Eucalyptus grandis , Pinus elliottii and Peltophorum dubium seedlings. The survey of the soil microorganism population was carried out in a greenhouse during 60 days and the treatments consisted of applications of copper sulphate (0.7; 0.708; 0.716; 0.724 mg Kg -1 ) to the soil and to eucalyptus and pinus seedlings. Eucalyptus and Peltophorum dubium seedlings inoculated and not inoculated with Pisolithus microcarpus (Cooke and Massee) Cunn (UFSC Pt 116) received copper levels of 0, 100, 200 and 300 mg kg -1 . The height, stem diameter, shoot and root fresh biomass, shoot and root dry biomass and ectomycorrhizal colonization were evaluated at 110 days. Soil bacteria and fungus population were altered by the presence of copper and the eucalyptus and pinus seedlings were not affected by copper addition. The inoculation of the eucalyptus and canafistula seedlings with isolate UFSC Pt 116 favored the height of the plants and the development of shoot and root fresh biomass. According to the results, canafistula was able to form an ectomycorrhizal association with the isolate tested. The eucalyptus and canafistula seedling development was inhibited by copper following inoculation with the UFSC Pt 116 isolate.

Ectomicorrizas em Grápia [ Apuleia leiocarpa (Vogel) J.F. Macbride] e canafístula [ Peltophorum dubium (Sprengel) Taubert] in vitro

The ectomycorrhizal fungi association with native forest essences could be an alternative to improve the adaptation and the development of seedlings in reforested areas of Rio Grande do Sul State. The aim of this work was to identify and to characterize the ectomycorrhizal associations in Apuleia leiocarpa and Peltophorum dubium seedlings, under laboratory conditions. Four inoculation treatments with ectomycorrhizal isolates were used to Apelui leiocarpa : UFSM RA 2.8 ( Suillus sp.), UFSM RA 3.6, UFSC-Pt116 ( Pisolithus microcarpus ) and UFSC-Pt24 ( Pisolithus sp.) and one uninoculated as control. For P. dubium , were used the isolates UFSM RA 2.8 UFSC-Pt116, UFSC-Sc124 ( Scleroderma citrinum Pers.) and UFSC-Pt24 ( Pisolithus sp.), and control. For both forest essences there were seven replicates per treatment. It was analyzed the following parameters: height of plants, fresh matter of shoots and roots, dry matter of shoots and roots and presence of ectomycorhizal colonization. Ectomycorrhizas were observed in Apuleia leiocarpa seedlings inoculated with the isolate UFSM RA 2.8 ( Suillus sp.). This fungus also improved seedlings growth, as height of plants, fresh and dry matter of shoots, although, it was not statistically different from the other isolates. Seedlings of Peltophorum dubium presented evidences of ectomycorrhizal formation, like the presence of a fungal mantle.