Bayoud disease: monitoring of micoflora present in the soil of an Algerian oasis

Fusarium oxysporum (Schlecht.) Snyd. & Hans., the most common species of the genus, is widely distributed in soil and on organic substrates. The species includes non-pathogenic, plant and human pathogenic strains. F. oxysporum f. sp. albedinis is the agent of bayoudh disease, causing the death of millions of mature and young date palm trees in North Africa. The aim of this work was to examine any correlation between the total microbial com- munity and the incidence of the disease in an Algerian oasis. A total of 38 soil samples were collected in 12 areas randomly cho- sen within the oasis of Azoua and screened for the presence of fungi, bacteria and actinomycetes. Microbes were isolated on se- mi-selective substrates (PDS, TSA and Chitin-Agar media). Mi- crobial entities were identified according to their morphological traits. For each soil sample, a statistical index of richness, domi- nance and evenness was determined. The microbial load ranged from 1.24 × 10 3 to 9.07 × 10 4 CFU/g for fungi, 4.00 × 10 5 to 3.22 × 10 7 CFU/g for bacteria and 8.60 × 10 4 to 9.92 × 10 6 CFU/g for actino- mycetes. The correlation between the incidence of bayoudh dis- ease, evaluated on a visual scale, in each area and the microbial community is reported