"PGPR, paranodules, stimulation de la croissance et tolérance au déficit hydrique chez le blé dur (Triticum durum Desf.)"

Abstract

"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."