Biocontrol of Damping off Disease in Brinjal (Solanum melongena) and Tomato (Solanum lycopersicum) by Arbuscular Mycorrhiza

Abstract

Arbuscular Mycorrhiza (AM) fungi are recognized as bioprotectors of plants for their ability to enhance plant health and provide protection against pathogens. This study determines the ability of AM fungi (mixed AM inoculum of Glomus mosseae) to suppress the damping off disease of brinjal and tomato seedlings affected by the pathogenic fungi. This experiment consisted of two factors viz. AM fungi inoculation (inoculated and non-inoculated) and pathogen inoculation (Sclerotium rolfsii, Rhizoctonia solani, Fusarium oxysporum, and control). A completely randomized design was used to lay out the treatments, with three replicates per treatment. Preliminary experiments were conducted to select the virulent isolates of Sclerotium rolfsii, Rhizoctonia solani, and Fusarium oxysporum against tomato and brinjal seedlings before setting the experiment for integration of AM fungi. The interaction of AM fungi and root-infecting pathogens was investigated under control conditions. Inoculation with pathogenic fungi Sclerotium rolfsii, Rhizoctonia solani, and Fusarium oxysporum significantly increased damping off disease and reduced the plant height, root length, root, and shoot weight of brinjal and tomato compared to control. Seedlings inoculated with AM fungi had a lower incidence of damping off disease than AM fungi non-inoculated seedlings in spite of pathogenic fungi inoculation. About 50% of the pre-and post-emergence damping off disease was reduced due to AM fungi inoculation in brinjal and tomato. The root colonization by AM fungi and AM fungi spore density in the rhizosphere of brinjal and tomato was also higher in the AM fungi inoculated seedlings. The plant height, root length, and root and shoot weight of brinjal and tomato were also increased due to AM fungi inoculation. Therefore, the AM fungi can be inoculated to suppress the damping off diseases and vigorous seedling production of brinjal and tomato.