| Acid deposition is one of the air environment problems, which commonly existed in our conutry. With the rapid economic development, the problem has become increasingly complex and difficult to be controlled. Plant-soil system constitutes the basic unit of terrestrial ecosystems, As the main body of terrestrial ecosystem, pants are the major receptor from acid deposition. The acid deposition problems are getting more and more serious. It is very difficult to take proper measure to protect indigenousspecies at present. The traditional methods may cause some potential harmful environmental issues. It is very necessary to seek some more effective methods to control the impact of acid deposition. Ectomycorrhizal is widely existed in forest which has a close relationship with the plant-soil system. In order to deeply find out the inner relationship of soil-Ectomycorrhizal-plant, an investigation of Pinus massoniana forest was carried out in the in the south area of china. Besides, several strains of ectomycorrhizal fungi obtained from the fruiting bodies in Chongqing were exposed to acid and aluminum solution. The main objective of this study was to select the ectomycorrhizal fungi with the resistance ability to acid and Al. This research results will have benefits to improve the forest health and recovery ecosystem balance. Also, it can provide a theoretical basis for the protection forest from acid deposition.The inner relationship between soil-Ectomycorrhizal-plant each other was indicated by nutrient element contents in leaf, the pH value of soil, as well as the content of nutrient elements in soil.The experiment was set up as a complete two factorial design, with the factors pH (3.5,4.5,5.5) and the factor aluminium (0,0.2,0.5,1.0mM Al in the nutrient solution) and the experimental units as replicates. The influence of acid or aluminum concentration on biomass yield was determined by growing the isolates in a liquid Pachlewski medium at twelve levels. The contents of this elements including Ca, K, Mg, P in the mycelium and the pH in the medium were determined, separately. The conclusions are as follows:The analys is results of the soil samples indicated that the pH value was lower in TSP than LGS and LXH. The index of infection of Ectomycorrhiza is ordered as: LGS>TSP>LXH>CJT and the infection intensity index is ordered in4regions as: LGS>TSP>CJT>LXH.The analysis results of the plant leaf samples indicated that the TSP was relatively high in the nutrients. It perhaps resulted from the index of infection and infection intensity index. And CJT showed the opposite results.After acid and Al were elevated in liquid medium, the pH value is changed at the end of the experiment This may be resulted from the exudation of organic acids or other substances by ectomycorrhizal fungi.When exposed to acid and Al, the concentrations of nutrient elements in medium of9fungi was affected. Enhancing the ability of nutrient uptake is possibly one of the mechanism of mitigation of acidand Al stress by ectomycorrhizal fungi.Acid and Al in the liquid medium had different influences to the nine fungi. The nine fungi can be separated two types from the experimental results. One is significantly affected by acid and Al, and the other is sensitive to the acid and Al such as JYS2, JYS4, and JYS5. |
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