Biocontrol Potential of Arbuscular Mycorrhizal Fungi on Soil-borne Pathogens in Rice and Other Crops

Abstract

Arbuscular mycorrhizal fungi (AMF) are soil-borne fungi that form mutualistic symbiosis with plant roots, and can significantly improve plant nutrient uptake and increase resistance to several biotic and abiotic stresses. Though most rice cultivation systems involved submerged growing conditions, researchers are exploring the potential of AMF colonization and its benefits for rice. AMF has a potential of serving as a biocontrol agent in rice plants via direct mechanisms viz. nutrient improvement, competition, integration, morphological, biochemical, and physiological alteration and indirectly via induction of systemic induced resistance (ISR) in plants. Furthermore, other biotic factors (host genotype, age of the plant, species of AMF that is involved, degree of mycorrhization, presence of weed plants) and abiotic factors (soil temperature, moisture, nutrient content, and atmospheric gas composition, crop management systems) can be affected the process of biocontrol by AMF. These different mechanisms cannot be considered completely independent from one another. The potential for biocontrol by AMF depends mainly on all these mechanisms in conjunction with all of the other biotic and abiotic factors that affect mycorrhization. By considering such mechanisms, in this review we discussed the suitability of the application of AMF as a pathogen biocontrol agent in rice and the other crop plants, while reducing the application of chemical agents to control the diseases. However, for considering AMF as a better alternative for the synthetic agrochemicals, more research should be conducted by applying AMF and synthetic chemicals to compare the levels of pathogen control.