Experiments were conducted in 2009-2010 at Agricultural and Natural Resources Research Center of Yazd, Iran to study the effect of nitrogen levels and Plant Growth Promoting Rhizobacteria (PGPR) containing Azotobacter sp. and Azospirillum sp. on seed yield, its components and quality traits of sesame cultivars. Treatments were arranged in a factorial experiment based on RCBD with nitrogen rates [0 (Control), 25 and 50 Kg N ha −1 ], cultivars (Darab-14, GL-13 and Local) and Nfixing bacteria levels (non-inoculation and inoculation) were applied with three replications.Nitrogen fertilizer significantly increased yield and yield components, but reduced oil content in A c c e p t e d M a n u s c r i p t 2010. Inoculating seeds with PGPR increased yield and yield components of sesame cultivars compared to the control treatment. Seed yield in PGPR inoculation with half a rate of N fertilizer treatment was more than seed yield in the full rate of N fertilizer without a PGPR inoculation treatment. N fertilizer and PGPR application significantly decreased saturated fatty acids (palmitic and stearic acid) while it significantly increased unsaturated fatty acids (oleic and linoleic acid).Oleic acid had a significant negative correlation with the linoleic acid (r=-0.79). The result showed that an application of PGPR could be usefully applied to reduce use of chemical fertilizer.

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The early stages of quinoa germination are sensitive to drought stress. For this purpose, a study entitled the effect of selenium in different concentrations on germination characteristics and some antioxidant enzymes of quinoa under drought stress conditions with polyethylene glycol (PEG 6000) was investigated. The first experimental factor was seed priming with selenium (from two sources: sodium selenate and selenium nanoparticles: SeNPs ≈ 33.4 nm) at 0.5, 1.5, 3, 4.5, 6 mg•L −1 concentrations, besides, no priming treatment was used as control. The second factor was drought stress with PEG 6000 in concentrations 0, -0.4, -0.8, and -1.2 MPa. Drought stress with accumulation of reactive oxygen species (ROS) had a negative effect on most of the measured traits. In seeds that were primed with appropriate selenium concentrations, germination parameters and antioxidant enzyme activity as well as proline and protein content increased compared to the control treatment. Under conditions of severe stress (-1.2 MPa), the highest activity of catalase (CAT), superoxide dismutase (SOD), and ascorbate peroxidase (APX) enzymes was observed in prime with selenium nanoparticles at concentrations of 4.5, 6.0 and 4.5 mg•L −1 , respectively. Concentrations higher than 3 mg•L −1 of selenium nanoparticles and concentrations of 3 mg•L − 1 sodium selenate had the highest accumulation of photosynthetic pigments under control (stress-free) conditions. The present study shows that selenium priming can reduce the harmful effects of drought stress on quinoa by altering germination properties and biochemical properties.

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