Evaluation of rhizospheric Pseudomonas spp. for the management of Fusarium wilt of tomato in Cholistan, Pakistan

Agriculture plays a crucial role in national development, food security, and poverty reduction. Despite its importance, the agricultural sector's contribution to GDP is gradually decreasing. Fusarium wilt, caused by Fusarium oxysporum f.sp. lycopersici, has significantly hindered tomato production globally. Tomato (Lycopersicon esculentum Mill.), a widely grown vegetable, is threatened by various pathogens, with Fusarium wilt being particularly damaging due to yield and quality loss. Synthetic chemicals are commonly used to control Fusarium wilt in tomatoes, but these chemicals are harmful to the environment and human health due to their toxicity and persistence. This has prompted researchers to develop eco-friendly alternatives. In preliminary tests, 10 isolates of Pseudomonas spp. were evaluated in vitro against Fusarium oxysporum. Four isolates that effectively inhibited the growth of F. oxysporum were chosen for further experimentation. A greenhouse study revealed that two bacterial isolates, IUB310 and Mad1230, significantly reduced disease severity by 69.2% and 65%, respectively. Plant growth-promoting rhizobacteria from the Pseudomonas family not only combat pathogens but also induce systemic resistance in plants by strengthening cell walls and triggering defensive proteins and compounds. The results clearly highlight the significance of Pseudomonas strains in suppressing F. oxysporum and promoting plant growth, indicating their potential use in managing Fusarium wilt in tomato cultivation.