Mycorrhizal fungi as control agents against plant pathogens

Abstract

Biofertilizers comprise single or consortia of living microorganisms which are responsible for the direct or indirect benefits rendered to growth of various plants. These microbial inoculants are produced from cultures of certain soil organisms that can improve soil fertility and crop productivity. They solubilise phosphorous, fix atmospheric nitrogen, oxidize sulfur, decompose organic material and alter the dynamics and properties of soil resulting in various benefits to plant growth and crop production. Biofertilizers help to increase access to nutrients thus providing growth-promoting factors for plants. This increased availability and efficient absorption of nutrients stimulates plant growth by hormone action and improves crop yield. One of the most abundant fungi in agricultural soil, the arbuscular mycorrhizal (AM) fungi, play a very important role as biofertilizers. They form mutualistic relationships with roots of 90% of plants, promote absorption of nutrients and water, control plant diseases, and improve soil structure. Plants colonized by mycorrhizae grow better than those without them and are beneficial in natural and agricultural systems. The use of AM fungi as biofertilizers is not new; they have been produced for use in agriculture, horticulture, landscape restoration, and soil remediation for almost two decades.