Bacteriological Therapeutic-Based Strategy for Management of Fusarium Wilt Disease in Tomato Plants

Abstract

Fusarium oxysporum f. sp. lycopersici (Sacc) causes a destructive wilt disease in tomato. With consideration to the environment and human health concerns, the bioagents as alternative procedures for defense against the plant pathogen were investigated. The potentiality of the antagonistic activity of Bacillus subtilis (ATCC® 11774™) reached 53% against the growth of F. oxysporum in a dual culture technique. The proteolytic; B. subtilis strain; was found to be a potent producer of amino acids under in vitro. Fractionation of the fermented hydrolysate showed the liberation of glutamic acid (760.15 mg/L), glycine (414.65 mg/L), aspartic acid (291.1 mg/L), cysteine (268.45 mg/L) and lysine (51.9 mg/L). In a greenhouse experiment, seed treatment with crude extract of amino acids and/or Bacillus subtilis cells demonstrated the greatest suppression of wilt symptoms on tomato seedlings. Moreover, pronounced plant growth promotion in root and shoot lengths, number of leaves, shoot fresh and dry weights of tomato plants was noticed. Biochemical parameters (photosynthetic pigments, total polyphenols, flavonoids, polyphenol oxidase, and peroxidase enzymes) were also upgraded. Antioxidant capacity of the plants – ABTS (%), DPPH (%) and reducing power – positively responded to the investigated treatments.