To understand the role of ectomycorrhizas in improving the tolerance of its host to excessive heavy metals in soil, this study was conducted to exam the patterns of four fractions (the exchangeable, the carbonate-boun...To understand the role of ectomycorrhizas in improving the tolerance of its host to excessive heavy metals in soil, this study was conducted to exam the patterns of four fractions (the exchangeable, the carbonate-bound, the Fe-Mn oxide- bound and the organically bound) of both Cu and Cd in the rhizosphere of Chinese pine (Pinus tabulaeformis) seedlings grown in excessive Cu and Cd environment. The results showed that the speciation of Cu and Cd in the rhizosphere was significantly influenced by inoculation of ectomycorrhizal fungus Boletus edulis. Compared to the rhizosphere, the content of exchangeable Cu slightly decreased in the mycorrhizosphere of the seedlings grown in 166 and 400 mg kg-1 Cu contaminated soil, whereas the exchangeable Cd in the mycorrhizosphere decreased remarkably to only 33% and to 60% that of the rhizosphere at 0.75 and 1.50 mg kg-1 Cd levels, respectively. These indicate the potential capacity of mycorrhizas to alleviate the damage of heavy metals to the host plants by reducing the bioavailability of heavy metals in soil. Distribution of the 4 tested fractions of Cu and Cd at different contamination levels showed that there was a strong tendency of changing from loosely associated fractions to strongly associated fractions in the mycorrhizosphere. The most stable Cd fraction, organically bound Cd, was significantly larger in the mycorrhizosphere than in the rhizosphere at different Cd contamination levels. This phenomenon was also observed for Cu but the difference was not statistically significant.展开更多
Forty species of Basidiomycota from 21 genera in 15 families, collected from Liuxihe National Forest Park, Guangzhou, China, have values for use by local people. More than half of the species collected are edible, and...Forty species of Basidiomycota from 21 genera in 15 families, collected from Liuxihe National Forest Park, Guangzhou, China, have values for use by local people. More than half of the species collected are edible, and some (Lactarius deliciosus, Boletus spp.) are gathered for commercial consumption in South China. Ten species have medicinal properties, and include Dictyophora, Ganoderma, Pisolithus and Scleroderma. Over 60% species (26 taxa) are ectomycorrhizal involving 12 edible fungi. The most abundant families were the Amanitaceae, Boletaceae and Sclerodermataceae, which form important ectomycorrhizal associations with coniferous and mixed broad-leafed trees in the Park. Prospective uses of these macrofungi are discussed.展开更多
基金the National Natural Science Foundation of China (No.20777004).
文摘To understand the role of ectomycorrhizas in improving the tolerance of its host to excessive heavy metals in soil, this study was conducted to exam the patterns of four fractions (the exchangeable, the carbonate-bound, the Fe-Mn oxide- bound and the organically bound) of both Cu and Cd in the rhizosphere of Chinese pine (Pinus tabulaeformis) seedlings grown in excessive Cu and Cd environment. The results showed that the speciation of Cu and Cd in the rhizosphere was significantly influenced by inoculation of ectomycorrhizal fungus Boletus edulis. Compared to the rhizosphere, the content of exchangeable Cu slightly decreased in the mycorrhizosphere of the seedlings grown in 166 and 400 mg kg-1 Cu contaminated soil, whereas the exchangeable Cd in the mycorrhizosphere decreased remarkably to only 33% and to 60% that of the rhizosphere at 0.75 and 1.50 mg kg-1 Cd levels, respectively. These indicate the potential capacity of mycorrhizas to alleviate the damage of heavy metals to the host plants by reducing the bioavailability of heavy metals in soil. Distribution of the 4 tested fractions of Cu and Cd at different contamination levels showed that there was a strong tendency of changing from loosely associated fractions to strongly associated fractions in the mycorrhizosphere. The most stable Cd fraction, organically bound Cd, was significantly larger in the mycorrhizosphere than in the rhizosphere at different Cd contamination levels. This phenomenon was also observed for Cu but the difference was not statistically significant.
文摘Forty species of Basidiomycota from 21 genera in 15 families, collected from Liuxihe National Forest Park, Guangzhou, China, have values for use by local people. More than half of the species collected are edible, and some (Lactarius deliciosus, Boletus spp.) are gathered for commercial consumption in South China. Ten species have medicinal properties, and include Dictyophora, Ganoderma, Pisolithus and Scleroderma. Over 60% species (26 taxa) are ectomycorrhizal involving 12 edible fungi. The most abundant families were the Amanitaceae, Boletaceae and Sclerodermataceae, which form important ectomycorrhizal associations with coniferous and mixed broad-leafed trees in the Park. Prospective uses of these macrofungi are discussed.
