Résumé:
Endophytic fungi have shown significant potential to improve plant tolerance to salinity. Our study, conducted in vitro and in vivo, focused on the effect of Aspergillus niger, an endophytic fungus isolated from a marine algae, on germination, emergence and growth of durum wheat (Triticum durum Desf) at different NaCl concentrations (0, 50, 100, 150 and 200 mM). The results obtained show a significant stimulation of the germination and emergence rate, even when the saline conditions faced by the plants are high. We observed an increased development of radicles, coleoptiles and a greater number of roots in the seedlings treated with the endophyte. Biochemical analysis performed on plants treated with Aspergillus niger revealed a significantly higher content of proline, a well-known osmoprotectant, in response to salinity stress, particularly at high concentrations compared to the control not treated with the fungus. Plants treated with Aspergillus niger accumulated higher chlorophyll a and b content compared to control plants without endophyte. When salinity reached its highest value (200 mM), its contents were even higher, suggesting an improvement in the physiological state of plants subjected to high NaCl concentrations.
These results suggest that the symbiotic association between durum wheat and Aspergillus niger could be a promising strategy to mitigate the adverse effects of salinity on crop growth and development. They may constitute, in the future, the beginning of a promising approach to managing salinity stress in crops within the framework of sustainable agriculture.
