Rhizospheric Niche of Beach Plum Seedlings Colonized by Arbuscular Mycorrhizal Fungi Relationship between Arbuscular Mycorrhizal Fungi and Soil Enzyme Activities of Beach Plum in Fujiabian Hilly Area Growth and Water Content of Beach Plum Cutting Seedlings under Salt Stress Effects of arbuscular mycorrhizal fungi on the rooting, growth and enzymatic activity relating to disease resistance of beach plum(Prunus maritima)cuttings