Mycorrhizal formation between seven ectomycorrhizal fungi and seedlings of three pines species Inocula Preparation of Ectomycorrhizal Fungi and Their Effects on the Growth of Pine Seedlings Effect of Soil Moisture Variations on Photosynthetic Characteristics of Slash Pine Seedlings Effects of Light Quality and Norflurazon on the Formation of Plastid Pigments in Cotyledons of Pinus sylvestris Effects of Some Ectomycorrhizas on Pine Seedlings to Disease Resistance