Significance of Mycorrhizae

Mycorrhiza is a mutualistic association between zone surrounding the root [2]. Although a lack in growth fungi and higher plants [1]. Different types of mycorrhizae response to VA-fungi inoculation in unsterilized soil was occur, distinguished by their morphology and to a also recorded, this result has been attributed to the fact certain extent, in their physiology. These include the that native VA-fungi may provide the potential benefit of ectomycorrhizae and endomycorrhizae. The this mutualistic association [6]. ectomycorrhizae characterized by an external sheath of It was reported that one of the principal avoidance fungal cells surrounding the root, often penetrates strategies of plants for adaptation to adverse soil between the cells of epidermis and the first few cells of conditions is an increase in root surface area via cortex and the fungal hyphae typically infect the mycorrhizae [7]. A better understanding of the roots of forest trees of the temperate region. While mycorrhizae of agronomic crops is needed because of endomycorrhizae like vesicular arbuscular mycorrhizal their potential involvement in systems of sustainable (VA) fungi forms no sheath, the fungus infects the root agriculture [8]. system of most cultivated crops and usually it invades several layers of the outer root cortex. VA-fungal hyphae penetrate individual cells and form arbuscules within the cell and vesicles outside their host cells which led to their name [2]. Vesicular-arbuscular mycorrhizal (VA) fungi colonize plant roots and ramify into the surrounding bulk soil extending the root depletion zone around the root system. They transport water and mineral nutrients from the soil to the plant while the fungus is benefiting from the carbon compounds provided by the host plant. Therefore VA-fungi have a pervasive effect upon plant form and function [3]. Little is known about the natural ecology of these fungal-plant associations and the effects of certain soil amendments with natural waste products. VA-fungi are associated with improved growth of many plant species due to increased nutrients uptake, production of growth promoting substances, tolerance to drought, salinity and transplant shock and synergistic interaction with other beneficial soil microorganisms such as N-fixers and P-solubilizer [4]. Symbiotic association of plant roots with VA-fungi often result in enhanced growth because of increased acquisition of phosphorus (P) and other low mobile mineral nutrients [5]. Effective nutrient extensive hyphal growth beyond the nutrient depletion