Development of natural, broad-spectrum, and eco-friendly bio-fungicides is of high interest in the agriculture and food industries. In this context, Bacillus genus has shown great potential for producing a wide range of antimicrobial metabolites against various pathogens. A Bacillus velezensis strain FB2 was isolated from an agricultural field of National Institute for Biotechnology and Genetic Engineering (NIBGE) Faisalabad, Pakistan, exhibiting good antifungal properties. The complete genome of this strain was sequenced, and its antifungal potential was assayed by dual culture method. Moreover, structural characterization of its antifungal metabolites, produced in vitro, were studied. Genome analysis and mining revealed the secondary metabolite gene clusters, encoding non-ribosomal peptides (NRPs) production (e.g., surfactin, iturin and fengycin) and polyketide (PK) synthesis (e.g., difficidin, bacillaene and macrolactin). Furthermore, the Bacillus velezensis FB2 strain was observed to possess in vitro antifungal activity; 41.64, 40.38 and 26% growth inhibition against major fungal pathogens i.e. Alternaria alternata, Fusarium oxysporum and Fusarium solani respectively. Its lipopeptide extract obtained by acid precipitation method was also found effective against the above-mentioned fungal pathogens. The ESI-MS/MS analysis indicated various homologs of surfactin and iturin-A, responsible for their antifungal activities. Overall, this study provides a better understanding of Bacillus velezensis FB2, as a promising candidate for biocontrol purposes, acting in a safe and sustainable way, to control plant pathogens.

Potato (Solanum tuberosum L.) is one of the emerging staple crops in Pakistan, with Punjab producing over 95% of the country’s potatoes. Wilt is an emerging threat to the potato crop worldwide, including in Pakistan. We identified and characterized Fusarium species associated with potato wilt in Pakistan through morphological and molecular analyses. Samples were collected during the 2020–2022 potato seasons from five major potato-growing regions: Sahiwal, Chichawatni, Pakpattan, Kamalia, and Faisalabad. Morphological characterization, internal transcribed spacer (ITS) sequencing, specific translation elongation factor 1-alpha (TEF) sequencing, and phylogenetic analysis were used to identify six different Fusarium species: F. oxysporum, F. equiseti, F. incarnatum, F. fujikuroi, F. annulatum and F. thapsinum. Pathogenicity tests in a greenhouse revealed that F. oxysporum and F. equiseti were responsible for Fusarium wilt in all sampled regions, with F. oxysporum being more prevalent in wilted samples. This is the first report of F. equiseti on wilted potatoes in Pakistan. In vitro biocontrol tests using Trichoderma harzianum showed 89% inhibition against F. equiseti and 65% inhibition against F. oxysporum. These findings on F. equiseti will aid in developing future control strategies, including biocontrol measures for Fusarium wilt in potatoes.