Binucleate Rhizoctonia spp. as a biocontrol agents against plant pathogens

Abstract

Rhizoctonia spp. is a large, diverse, ubiquitous soil inhabiting group of fungi. They are generally regarded as plant pathogens causing root rot and other plant diseases which results in crop losses of many economically important plant species, but they can also enter into symbiotic associations with orchids. Binucleate species commonly cause root, stem and foliar diseases, but due to its wide range of host plants and frequent causing losses in important agricultural crops, probably the most studied Rhizoctonia species is multinucleate Rhizoctonia solani Kuhn. Crops, including fruits and vegetables, are exposed to diseases caused by microorganisms, especially pathogenic fungi, during growth and after harvest. The occurrence of plant diseases results in lower harvest, in worsens their quality and raises production costs. The use of chemical plant protection results in the contamination of soil and increase pathogen resistance to commonly used fungicides. Biological control is an alternative and safe for the environment method of plant protection. Hypovirulent BNR isolates from different anastomosing groups can be successfully used as biocontrol agents in plant protection against pathogenic Rhizoctonia and fungi from other species. They may occupy the same ecological niches as pathogens, compete successfully for nutrients, induce plant resistance and promote plant growth.