Evaluation of Inhibition of Fungal Spore Germination by Rhizospheric Bacterial Extracts

Aims: This work aims to evaluate the anti-germinative activity of bacterial extracts. These bacteria were already characterized for their antagonistic capacity in vitro against telluric phyto-pathogens fungi: Fusarium oxysporum f.sp. albedinis (Foa), Fusarium solani var. coeruleum (Fsc) and Phytophthora infestans (Pi), causing Bayoud, dry rot and mildew diseases respectively.

Methodology: The OD of bacterial cultures is measured in order to determine the microbial charge producing the anti-germination substances, then centrifuged, filtered. A volume of spore suspension of determined concentration is added to a determined volume of the bacterial filtrates. After incubation, for 24 hours at room temperature the inhibition of spore germination is observed under a microscope using a Malassez cell.

Results: The results showed that these bacterial filtrates are able of inhibiting fungal spore germination, among these filtrates XI35 ' one, gave a total inhibition (100%) on both of the tested fungi Foa and Fsc, while on Pi it only gave 16.66% of inhibition.

Conclusion: The bacterial filtrates were more active against mitosporic fungi, than oomycetes.