Antagonist activity of bacteria isolated from “Solanum elaeagnifolium” green compost against Fusarium oxysporum f.sp.radicis-lycopersici

In the present study, 14 bacteria were isolated from “Solanum elaeagnifolium” green compost belonging to 12 species: Paenibacillus macerans, Bacillus circulans, Geobacillus thermoglucosidasius, Bacillus licheniformis, Serratia liquefaciens, Bacillus megaterium, Paenibacillus glucanolyticus, Serratia marescens, Pseudomonas aeruginosa, Sporosarcina pasteurii, Lysinibacillus sphaericus and Brevibacillus laterosporus. For Pseudomonas aeruginosa and Brevibacillus laterosporus, two different strains were obtained for each species. All the 14 isolates were tested for their antagonistic activity on Fusarium oxysporum f.sp.radicis-lycopersici the causal agent of tomato crown and root rot (FCRR). The assessment of the in vitro interactions between bacterial strains and the phytopathogenic fungi was performed by dual confrontation assays on PDA medium. All the 14 bacteria were antagonistic against the phytopathogen, with an inhibitory effect varying between 67,14% and 52,85%. Sporosarcina pasteurii and Brevibacillus laterosporus (S12-2) showed antifungal effect higher than the other bacteria, where they exhibit an significant reduction in fungal mycelium growth about 67,14%. The presences of different antagonist species of bacteria witnessed the maturity of the green compost and make it as a good organic amendment for tomato plant culture for stimulate their growth and to protect them from FORL. The inventory of the bacterial community of this compost was necessary to determine its quality for an appropriate application of them in future as a biological control agent against FORL in tomato cultivation.