Using protoplast fusion to improve biocontrol ability of Fusarium oxysporum against Egyptian broomrapes (Phelipanche Aegyptiaca)

To effectively combat parasitic weeds, it is essential to develop advanced biocontrol agents capable of thriving in diverse environmental conditions. The objectives of this study were to evaluate the potential of Fusarium oxysporum isolates as biocontrol agents against Egyptian broomrapes in tomato crops and to explore whether protoplast fusion could improve their biocontrol ability. Eleven F. oxysporum isolates significantly reduced the germination of Phelipanche aegyptiaca seeds. Consequently, these isolates were further evaluated for their potential as biological control agents against broomrapes through glasshouse and field experiments. The isolate KGh2-1 of F. oxysporum showed the highest reduction in the number of emerged broomrapes in both trials (p < 0.001). In order to enhance biocontrol activity against broomrapes, protoplast fusion was performed between F. oxysporum and F. equiseti. In comparison to KGh2-1, the fusant strains demonstrated superior ability in inhibiting the growth of broomrapes. The results also showed a clear host specificity of the selected pathogenic isolates and fusants. Protoplast fusion can be recommended as a valuable tool that can efficiently enhance the biocontrol ability of F. oxysporum against broomrapes.