ABSTRACT

Introduction The term mycorrhiza, derived from two words ‘mycos’ and ‘rhiza’, literally means ‘fungus root’. Frank (1885) for the first time proposed this term to describe the mutualistic association occurring between plant root and fungi [1]. Mycorrhizal associations are categorized into two classes: Ectomycorrhiza and Endomycorrhiza. The ectomycorrhiza are, generally, associated with the roots of higher woody perennials. These fungi form intercellular hyphal ramification with the host cortex i.e., hartig net and dense hyphal covering to roots (i.e., mantle). Endomycorrhiza is characterized by fungal penetration of the host cell where three categories are recognized. These are orchidaceous, ericoid and arbuscular. The associated endophyte in first two belongs to higher fungi with septate hyphae. An intermediate group with septate, inter-and intracellular mycelium was placed in a separate group called Ectendomycorrhiza [2]. Arbuscular mycorrhizal (AM) symbiosis, also referred as vesiculararbuscular mycorrhizal symbiosis [3], is the most common and has been estimated to occur in more than 80% of flowering plant species [2]. These associations are extremely ancient and AM fungi have even been identified in fossils of early Devonian land plants [4].