Domiciliation of <i>Trichoderma asperellum</i> Suppresses <i>Globiosporangium ultimum</i> and Promotes Pea Growth, Ultrastructure, and Metabolic Features

The beneficial microorganisms represent a new and hopeful solution for a sustainable environment and development. In this investigation, Trichoderma asperellum ZNW, isolated from seeds, was domiciliated within the pea plant for improving growth, disease management, and enhancement of productivity. Globisporangium ultimum NZW was isolated from deformed pea seeds, representing the first record of the pathogen caused by pea damping-off. Both fungi were molecularly identified. T. asperellum ZNW produced several lytic enzymes and bioactive metabolites as detected by GC-MC. The SEM illustrated the mycoparasitic behavior of T. asperellum ZNW on G. ultimum NZW mycelia. In the pot experiment, T. asperellum domiciliated the root and grew as an endophytic fungus, leading to root vessel lignification. Under soil infection, T. asperellum reduced damping-off, by enhancing peroxidase, polyphenol, total phenols, and photosynthetic pigments content. The vegetative growth, yield, and soil dehydrogenase activity were improved, with an enhancement in the numerical diversity of the microbial rhizosphere. This work may enable more understanding of the plant-fungal interaction, yet, working on domiciliation is recommended as a new approach to plant protection and growth promotion under various ecological setups

New Strategy for Inducing Resistance against Bacterial Wilt Disease Using an Avirulent Strain of <i>Ralstonia solanacearum</i>

Ralstonia solanacearum is one of the globally significant plant pathogens that infect a wide host range of economically important plants. A study was conducted to evaluate the hypothesis that an avirulent strain of R. solanacearum can act as a biocontrol mediator for managing potato bacterial wilt. Virulent R. solanacearum was isolated and identified (GenBank accession number; OP180100). The avirulent strain was obtained from the virulent strain through storage for 3 weeks until the development of deep red colonies. The virulent strain had higher lytic activity than the avirulent strain. Tubers’ treatments by the avirulent strain of R. solanacearum, (supernatant, boiled supernatant, and dead cells) significantly reduced plant disease rating and increased the growth, physiological activities, and biomass of potato compared to the untreated, infected control. The major components detected by GC–MS in the supernatant revealed 10.86% palmitic acid (virulent), and 18.03% 1,3-dioxolane, 2,4,5-trimethyl- (avirulent), whereas the major component in the boiled supernatant was 2-hydroxy-gamma-butyrolactone in the virulent (21.17%) and avirulent (27.78%) strains. This is the first research that assessed the influence of boiled supernatant and dead cells of virulent and avirulent R.solanacearum strains in controlling bacterial wilt disease. Additional work is encouraged for further elucidation of such a topic