Résumé:
Chickpea is one of the most important legumes in Algeria. Surveys have shown the
appearance of vascular wilt of chickpeas in northwestern of Algeria. This disease is caused
by the plant pathogenic fungus Fusarium oxysporum f. sp. ciceris (FOC). Surveys were
conducted during the 2008 crop year in four regions of northwestern Algeria that allowed
us to detect the presence of wilt symptoms in all fields surveyed. The involvement of the
FOC in the manifestation of wilt has been demonstrated and isolates carried testified to the
colonization of the stem. FOC isolates showed variable pathogenicity. The use of
antagonistic microorganisms is considered as promising method to ensure a successful
protection against FOC. Furthermore 29 antagonistic rhizobacteria were selected among
131 isolated from the chickpea rhizosphere grown in nine regions of the northwest and
northeast of Algeria: Mascara, Sidi Bel-Abbes, Tlemcen, Tiaret, Mostaganem, Relizane,
Chlef, Guelma and Constantine. In vitro comparison tests between two isolates of FOC
(FOC1 and FOC2) and 29 rhizobacteria separately showed inhibitory activity of the
mycelial growth of the two pathogens of 25.63% to 71.11% by direct confrontation and
14.11% to 45.74% b indirect confrontation. All the isolates have the ability to solubilize
phosphate, as well as the production of HCN, AIA and chitinase. These characteristics as
they are called PGPR. Five performing species were identified as B. subtilis (Rb29), B.
amyloliquefaciens (Rb4), B. megaterium (RB6), B. lentus (RB12), B. mycoides (RB15) and
selected for control testing in vivo biological. These species have significantly reduced the
incidence of vascular wilt after a bacterial inoculation of susceptible cultivar ILC 482
seeds of 60-99% in pot and 57.20 to 98% in the field. This study revealed that the
rhizospheric species of chickpea belonging to the genus Bacillus can be used as biological
control agents.
