Résumé:
"The use of PGPR (Plant Growth Promoting Rhizobacteria) a biological approach seems
promising solution to improve the production of durum wheat (Triticum durum Desf.) in Algeria.
Recent research has shown that the use of PGPR as an inoculant is a sustainable alternative to organic
crop production.
Characterization of isolated from the rhizosphere of several regions in eastern Algeria (Ain El
bey Constantine, El Khroub-Constantine (zoneA), El Khroub-Constantine (zoneB), El Khroub-
Constantine (El Baraouia zone1), El Khroub-Constantine (El Baraouia zone2), Mila, Souk Ahrass,
Setif, Batna and Tebessa) bacterial strains was performed to determine their morphological and
physiological properties. All isolates, except those isolated regions Mila, Batna and Ain El
Bey(Constantine), showed significant growth regardless of the medium composition and carbon
culture conditions in temperature and pH. In addition, it was found that most of the isolates showed
good tolerance to high concentrations of NaCl (700mM), unlike for other.
These strains were also tested for their PGPR effects by biochemical studies, the results clearly
show that these isolates belong to the genus Azospirillum; to confirm these results a molecular study
was performed to sequence the 16S rDNA gene. The phylogenetic tree obtained includes six strains in
the same close group of Azospirillum brasilense.
Our study has then been to highlight the effects of inoculation of durum wheat with
Azospirillum brasilense in controlled conditions in a greenhouse. The results show the importance of
A.brasilense paranodules in training and in the growth of root and aerial part of durum wheat.
Thereafter, the inoculation of durum wheat with actinomycete Frankia CcI3 has shown the
beneficial effects on root growth and on the formation of paranodules considered seats nitrogen
fixation.
Further studies on two varieties of durum wheat (GTA / DUR and WAHA) in the presence of
one water deficit (12% DC) also showed the ability of PGPR (Azospirillum brasilense, Bacillus sp.
CcI3 and Frankia) to restore growth."
