Mycorrhizae: An Overview

Abstract

Mycorrhizae establish symbiotic relationships with plants and play an essential role in plant growth, disease protection, and overall soil quality. Of the seven types of mycorrhizae described in current scientific literature (arbuscular, ecto, ectendo, arbutoid, monotropoid, ericoid and orchidaceous mycorrhizae), the arbuscular and ectomycorrhizae are the most abundant and widespread. This chapter presents an overview of current knowledge of mycorrhizal interactions, processes, and potential benefits to society. The molecular basis of nutrient exchange between arbuscular mycorrhizal (AM) fungi and host plants is presented; the role of AM fungi in disease protection, alleviation of heavy metal stress and increasing grain production is also reviewed. Use of mycorrhizae, primarily AM and ectomycorrhizae (ECM), on plant growth promotion and disease suppression are discussed and their implications on sustainable agriculture are considered. The effect of co-inoculation of AM fungi and beneficial saprophytic mycoflora, in terms of plant growth promotion and root colonization, are discussed. The role of AM fungi in the restoration of native ecosystems and the mycorrhizosphere effect of multitrophic interactions are briefly outlined. The mechanisms by which mycorrhizae transform a disturbed ecosystem into productive land are briefly discussed. The importance of reintroduction of mycorrhizal systems in the rhizosphere is emphasiszed and their impact in landscape regeneration and in bioremediation of contaminated soils are discussed. The importance of ECM in forest ecosystems, and associations of ECM in tropical rainforests and their function in maintaining tropical monodominance are discussed. In Vitro mycorrhization of micropropagated plants and visualizing and quantifying endorhizal fungi are briefly explained.