Botrytis cinerea, a causal agent of gray mold disease, is one of the most destructive fungal pathogens that leads to substantial global economic crop losses, especially for tomato plants. The present study aims to investigate the inhibitory effect of two microbial culture filtrates (BCA filtrate alone and combined with salicylic acid) of Trichoderma longibrachiatum and Pseudomonas sp. against the phytopathogenic fungus B. cinerea on tomato plants. The biochemical modifications, gray mold disease incidence, and fruit quality parameters of the tomatoes were determined according to tested treatments. The results showed that both fungi and bacteria were able to solubilize phosphate and produce IAA and HCN. T. longibrachiatum could produce hydrolytic enzymes (chitinase, protease, and glucanase). Otherwise, Pseudomonas sp. showed the capacity to produce catalase and amylase enzymes. Both microbial culture filtrates inhibited the hyphae growth of B. cinerea. The biocontrol efficacy, in vitro, was significant: up to 50% in terms of the growth inhibition rate at a concentration of 40%. The tomato seedlings’ growth was promoted by the separate preventive treatments of each micro-organism culture filtrate. In addition, disease severity in the tomato seedlings and fruit was significantly reduced. Furthermore, the combined treatment of tomato fruit with culture filtrates and salicylic acid induced significant biochemical and physiological changes in fruit firmness, juice yield, total protein, and ROS enzyme activities. The culture filtrates of T. longibrachiatum and Pseudomonas sp. can be recommended as an effective microbial biofungicide to control gray mold disease under storage conditions.

The nematicidal potential of five filamentous fungi as biological control agents (BCAs) against the root-knot nematode (RKN), Meloidogyne javanica, infecting tomato was assessed in vitro and in pot experiments. The five promising native taxa, namely Trichoderma longibrachiatum, T. harzainum, T. asperellum, Lecanicillium spp., and Metacordyceps chlamydosporia, were selected to compare their effectiveness against both chemical (Mocap, 10% ethoprophos) and biological (abamectin) nematicides on M. javanica reproduction indices and plant growth parameters. The stimulation of defense mechanisms was assessed by monitoring changes in the enzymatic activities of the polyphenol oxidase (PPO), peroxidase (POD), ascorbate peroxidase (APX), catalase (CAT), lipid peroxidation (MDA), phenols, and proteins content of tomato roots. The laboratory assays revealed that T. longibrachiatum, M. chlamydoporia, and Lecanicillium spp. seemed to be the most effective under laboratory conditions, with more than 60% of juvenile mortality. The egg infection rate was above 62%, and the egg hatching rate was below 32%. The direct parasitism by the five taxa was confirmed by scanning electron microscope observation. The results of this study found a similar parasitism mechanism for T. longibrachiatum, T. harzianum, and M. chlamydosporia, where their hyphae and spores adhered to the M. javanica juveniles cuticle layer and formed trapping rings around them. The pot experiment results showed that T. harzianum and Lecanicillium spp. enhanced the plant growth parameters. Trichoderma longibrachiatum, abamectin, and the ethoprophos-based nematicides effectively decreased the reproduction rates of the nematode. The Trichoderma species and M. chlamydosporia significantly reduced the gall index and female fecundity of RKN. The treatment with BCAs and chemical nematicides involved a significant increase in the antioxidant activities of nematode-infected plants. The ethoprophos and fungal treatments decreased the MDA and total phenols content compared with the nematode-infested seedlings. This paper analyzes the advancements made towards the effective and efficient biocontrol of M. javanica using different fungal taxa, especially T. longibrachiatum and M. chlamydosporia, and the implications of these advancements for sustainable agriculture and food security.