Osama, N. Massoud, Hanaa, A. Abo Kora and Ebtsam,M. Morsy. ( 2016). Response of Wheat (Triticum asativum) Yield to some Plant Growth Promoting Rhizobacteria (PGPR) and its Impact on Storage PeriodMiddle East Journal of Applied Sciences. Volume 06 : 379-387.
Abstract: Production of gibberellins, indole acetic acid, exoploysaccharides, phosphate solubilization (PS) and nitrogenase activity are main characteristics of the two used bacterial strains under this investigation. The beneficial bacterial strains and Arbuscular mycorrhizal fungi (AMF) can help wheat plants grown in newly reclaimed sandy soil to grow well and obtain better yield components. Therefore, two field experiments were carried out during two successive winter seasons of 2012/2013 and 2013/2014 to evaluate the ability of the tested bacterial strains Azotobacter chroococcoum and Bacillus polymyxa in addition to mycorrhizal fungi as plant growth promoters, nitrogen fixers and phosphate solublizers for enhancing growth and productivity of wheat (Triticum asativum) var. Gize 168, in the presence of 2/3 (two-third) of the recommended dose of mineral NP. Generally, Plant dry weight, plant height, number of tillers, colonization percentage of mycorrhizal fungi (%), dehydrogenase and nitrogenase activities were significantly increased with combined mixture of Bacillus polymyxa, Azotobacter chrococcoum and Arbuscular mycorrhizal fungi after 45 and 75 days of sowing during the two successive seasons. Moreover, high content of NPK in wheat seeds as well as crude protein % were determined. The combined mixture during first and second season of all (T8) also exhibited the highest grains yield 2.56 and2.55ton / fed and straw yield 3.55 and 3.60 ton / fed. respectively. The obtained results obviously revealed that the tested bacterial strains besides AMF in combined mixture succeeded to compensate the 1/3 dose of NP through N2- fixation and phosphate solubilization processes. Finally, the combined (mixture treatment) is considered the unique one as there was a markedly reduction in the pathogenic fungal diseases during storage after harvest. Therefore, the role of the used beneficial microorganisms is not only directed for promoting wheat growth and yield but also exceeded that to protect wheat seeds from hazard mycotoxins.
Keywords: (N2- fixation, plant growth promoters, P. solubilization, Arbuscular mycorrhizal fungi, Azotobacter chroococcoum, Bacillus polymyxa, Storage, mycotoxins, pathogenic fungi.)
