Nocardiopsis dassonvillei strain MB22 from the Algerian Sahara promotes wheat seedlings growth and potentially controls the common root rot pathogen Bipolaris sorokiniana

• Published in: Journal of plant pathology 2019-11, Vol.101 (4), p.1115-1125
• Main Authors: Allali, Khadidja, Goudjal, Yacine, Zamoum, Miyada, Bouznada, Khaoula, Sabaou, Nasserdine, Zitouni, Abdelghani
• Format: Article
• Language: English
• Subjects: Biomedical and Life Sciences; Life Sciences; ORIGINAL ARTICLE; Plant Sciences
• ISSN: 1125-4653; 2239-7264
• DOI: 10.1007/s42161-019-00347-x

The biocontrol potential and plant-growth-promotion activities of seventeen actinobacteria, isolated from roots of native plants and soils harvested in the Algerian Sahara, were investigated. All strains were tested in vitro against five soil-borne phytopathogenic fungi. Six out of seventeen strains were tested in vivo for their biocontrol potential against Bipolaris sorokiniana strain LB12 as well as for their growth-promotion activities of durum wheat (cv. Vitron) seedlings via seed treatments in sterilized and non-sterilized soils. The root rot disease severity index (DSI) of wheat plants derived from seeds treated with actinobacteria (biological seed treatment) was significantly lower (p < 0.05) compared with those obtained from non-treated wheat seeds sown in inoculated pots (positive control). The strain Nocardiopsis dassonvillei MB22 showed the highest biocontrol activity with the DSI much lower than that of the positive control (27.7% versus 90.8% when non-treated seeds were sown in infested soil). No significant difference was observed between the DSI of plants obtained from biological seed treatments with the strain MB22 and those derived from seeds treated with the chemical fungicide Difeconazole®. Biological seed treatment with the spores of the strain MB22 resulted in greatest increases in the dry weight, the root and shoot length of seedlings. In in vitro tests, the strain MB22 was positive for the production of indole-3-acetic acid, siderophores, hydrogen cyanide, showed chitinolytic activity and solubilized inorganic phosphates which are commonly known features for the plant-growth-promotion and biocontrol activities of a given strain.