Screening and in Vitro Evaluation of Native Pseudomonas Spp., against Nematode Pathogens and Soil Borne Fungal Pathogens

Abstract

The objective of this study was to assess the efficacy of native Pseudomonas spp., against root-knot nematode, Meloidogyne incognita and other soil borne fungal pathogens such as Fusarium oxysporum f. sp. Lycopersici and Sclerotium rolfsii. The eggs and second stage juveniles (J2) of M. incognita were exposed to each isolates of Pseudomonas spp., by diluting the standard culture filtrate to fifty percent and to undiluted culture filtrate (100%). Four isolates of Pseudomonas spp. (CRS3, CRS6, and CRS8 and CRS10) significantly induced inhibition of egg hatching and mortality of M. incognita juveniles. The per cent mortality was proportional to the concentration of culture filtrate and the duration of exposure period. The highest percentage of inhibition of egg hatching was recorded for CRS3 while mortality of second stage juveniles was found in the case of CRS10 in undiluted culture filtrate. The CRS6 caused 48% inhibition of Sclerotium rolfsii while CRS8 caused 58% inhibition of Fusarium oxysporum f. sp. lycopersici. Since meloidogyne infection can predispose plants to plant pathogens, these isolates show promise for management of nematode and disease complex of vegetable crops.