Abstract
Bacillus subtilis
SPB1 lipopeptides were evaluated as a natural antifungal agent against
Fusarium solani
infestation. In vitro antifungal assay showed a minimal inhibitory concentration of about 3 mg/ml with a fungicidal mode of action. In fact, treatment of
F. solani
by SPB1 lipopeptides generated excessive lyses of the mycelium and caused polynucleation and destruction of the related spores together with a total inhibition of spore production. Furthermore, an inhibition of germination potency accompanied with a high spore blowing was observed. Moreover, in order to be applied in agricultural field, in vivo antifungal activity was proved against the dry rot potato tubers caused by
F. solani
. Preventive treatment appeared as the most promising as after 20 days of fungi inoculation, rot invasion was reduced by almost 78 %, in comparison to that of non-treated one. When treating infected tomato plants, disease symptoms were reduced by almost 100 % when applying the curative method. Results of this study are very promising as it enables the use of the crude lipopeptide preparation of
B. subtilis
SPB1 as a potent natural fungicide that could effectively control the infection of
F. solani
in tomato and potato tubers at a concentration similar to the commercial fungicide hymexazol and therefore prevent the damage of olive tree.