Growth and Water Relations of P. tabulaeformis Seedlings Inoculated with Ectomycorrhizal Fungi

抄録

The effects of infection with two ectomycorrhizal fungi, Suillus luteus and Gomphidius viscidus, on the growth and drought-tolerance of Pinus tabulaeformis (Chinese pine) seedlings under water stress conditions were examined. The growth of plants inoculated with the mycorrhizal fungi was consistently greater than that of nonmycorrhizal plants. Six months after inoculation, dry weight of mycorrhizal plants was about 2.1 times greater. Under water stress condition, net photosynthesis rate, needle water potential, and water use efficiency of mycorrhizal plant increased significantly. From these experiments, growth and drought-resistance of P. tabulaeformis were shown to be enhanced significantly by infection with the mycorrhizal fungi. The ability of 3 fungi including Cenococcum graniforme to grow under conditions of low water potential was tested in pure culture. C. graniforme and S. luteus showed negligible growth with water potentials lower than -2.0MPa. However, G. viscidus continued to grow at -2.0MPa. All of the mycorrhizal fungi showed maximum growth at -0.5MPa.