Isolation, identification and pathogenicity of soil borne pathogens from tomato rhizosphere (Solanum lycopersicum L.)

Abstract

The diseases that are caused by pathogens which persist (survive) in the soil matrix and in residues on the soil surface are defined as “soil-borne diseases”. The soil is a reservoir of inoculum of these pathogens, the majority of which are widely distributed in agricultural soil. However, some species show localized distribution patterns. Most often damage to root and crown tissues of the plant is hidden in the soil. Thus these diseases may not be noticed until the above-ground parts of the plant are affected severely showing symptoms such as stunting, wilting, chlorosis, and death. The tomato plant is attacked by various diseases that significantly affect its growth and yield. Out of which the soil-borne diseases like fusarium wilt, bacterial wilt, stem rot, or white Mold are the most serious diseases affecting its yield. The results of the present study revealed that the three soil-borne pathogens were isolated from previously grown tomato fields and these were identified as Fusarium oxysporium f. sp. lycopersici, Ralstonia solanacearum, and Sclerotium rolfsii. The pathogenicity of the isolated pathogen was tested against the host plant and it observed that organisms were pathogenic to tomato plants.