In Morocco, a collaboration between the two national institutes ENAM (National School of Agriculture of Meknes) and FSTF (Faculty of Science and Technology of Fez) under the SIRAM project, has allowed the achievement of SIRAM CS3 activities focused on the understanding of rot root diseases of olive trees. In this CS3, biological treatments (Two antagonistic bacteria Alcaligenes faecalis ACBC1, Bacillus amyloliquefaciens (SF14) & and an endophytic fungus Trichoderma spp.) against this disease were assayed in pot experiments under greenhouse conditions (Figures 1, 2 & 3).
At the end of the experiment, soil samples were taken for DNA extraction, followed by 16S rRNA sequencing to determine the impact of biological treatments on the soil microbial community. The obtained results will be useful for the suppression of root rot diseases in olive trees. This approach will be coupled with different physicochemical properties, revealing changes in mineral components following biological treatments. All findings will determine if there is any correlation between disease severity and soil microbiome community and between disease suppression and soil physicochemical properties.
Figure 1: Inoculation of healthy olive plants with the pathogenic oomycete.
Figure 2: Seedling olive tree treated with bacterial suspension.
Figure 3: Symptoms of olive root rot disease on a one-year-old plant treated with bacterial isolates ACBC1, SF14, and endophytic fungus Tr2 and inoculated with Pythium schmitthenneri after two months within greenhouse conditions. C+: positive control (olive plants inoculated only with the pathogen), and C−: negative control (plants treated only with water in the absence of the pathogens.