Agricultural productivity is severely affected by major biotic and abiotic factors including drought, salinity, extreme temperatures and phytopathogens fungi. Durum wheat (Triticum durum Desf.) is considered one of the most important crops in the world. High salt stress has more pronounced effects on durum wheat growth and development, compared to other cereals. Several approaches have been proposed to reduce salinity effects on durum wheat, which includes the use of Plant Growth Promoting Bacteria (PGPB).

Actinobacteria represent a large group of microbial resources for wide practical use and high commercial value. In addition to their potential applications in stressed environments, actinomycetes can grow under diverse stress conditions such as high temperature and salinity.

The main objective of this work is to evaluate the effect of the thermophilic actinobacteria inoculation on the morpho-biochemical behavior of durum wheat plant subjected to salt stress and to investigate their antifungal potential against Aspergillus niger.

The effect of thermophilic actinobacteria WGS9, WSC2, WCD, OTH 1.2.2, OTH 1.3.1 and OTH 2.2.2.3 inoculations in saline condition on Triticum durum behavior was studied. The salt stress was generated by the application of different NaCl doses (0.3 M, 0.6 M, 0.9 M, 1.1 M, 1.4 M, 1.7 M).

The result of the two lots of the plants (inoculated and uninoculated) show an increase in the morpho-biochemical parameters of Durum wheat inoculated with actinobacteria strains (the length of the roots and stems, total chlorophyll content, total amino acids content, proline content) and this despite the salt concentration. The PGPB strains WGS9 and OTH 2.2.2.3 showed good in vitro antifungal (inhibition > 55%) control.

The inoculation by actinobacteria derived from Algerian ecosystem allowed us to observe the beneficial effect of these strains on alleviating salinity damages and their role in fighting the effects of biotic stressors (phytopathogenic fungi).