الفهرس 
INTRODUCTIONOnly 14 pages are availabe for public view
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Abstract
Mycorrhizal associations vary widely in structure and function, but the most common interaction is the vesicular arbuscular mycorrhizal (VAM) symbiosis. This interaction is formed between the roots of over 80% of all terrestrial plants include many agriculturally and horticulturally important crop species, and Zygomycetes fungi from the order Glomales (Smith and Read, 1997). These fungi are obligate symbionts which form endomycorrhizal symbioses (Frank et al., 1987) which conferes benefits directly to the host plant’s growth and development through the acquisition of P and other mineral nutrients from the soil by the fungus. In addition, they may also enhance the plant’s resistance to biotic and abiotic stresses. This relation benefits the plant growth by enabling a greater proportion of available nutrients in the soil to be absorbed into the plant. The fungal partner gets photosynthetic sugars as food from the plant which in turn acquires an array of benefits ranging from better uptake of phosphorus and relatively immobile micronutrients like zinc and copper (Harrier, 2001).The beneficial effects of the VAM symbiosis occur as a result of a complex molecular dialogue between the two symbiotic partners. Identifying the molecules involved in the dialogue is a prerequisite for a greater understanding of the symbiosis.