Mycorrhiza:A Mutualistic to Plant

Mycorrhiza is a mutualistic association between fungi and higher plants . Different types of mycorrhizae occur, distinguished by their morphology and to a certain extent, in their physiology. These include the ectomycorrhizae and endomycorrhizae. The ectomycorrhizae characterized by an external sheath of fungal cells surrounding the ischolar_main, often penetrates between the cells of epidermis and the first few cells of cortex and the fungal hyphae typically infect the ischolar_mains of forest trees of the temperate region. While mycorrhizae endomycorrhizae like vesicular arbuscular mycorrhizal (VA) fungi forms no sheath, the fungus infects the ischolar_main system of most cultivated crops and usually it invades several layers of the outer ischolar_main cortex. VA-fungal hyphae penetrate individual cells and form arbuscules within the cell and vesicles outside their host cells which led to their name. 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. Symbiotic association of plant ischolar_mains with VA-fungi often result in enhanced growth because of increased acquisition of phosphorus (P) and other low mobile mineral nutrients. Effective nutrient acquisition by VA-fungi is generally attributed to the extensive hyphal growth beyond the nutrient depletion zone surrounding the ischolar_main. Although a lack in growth response to VA-fungi inoculation in unsterilized soil was also recorded, this result has been attributed to the fact that native VA-fungi may provide the potential benefit of this mutualistic association.