The effects of priming and drought stress treatments on some physiological characteristics of tall wheat grass (Agropyron elangatum) seeds

ABSTRACT: Seed priming offers an effective means for raising seed performance in many plant species. In this study the effect of different seed priming treatments on germination ability of tall wheat grass were evaluated in two 3-replicated factorial experiment based on CRD design under normal and drought stress (?=-0/8 bar, applied with polyethylene glycol (PEG) 6000 )conditions. Priming was achieved by hydrating the seeds at 10, 15 and 25?C in the solution of PEG and urea with osmotic potential of -4 and -8 bar as well as distilled water (hydropriming) for 12, 24, 36, 48 and 60 hours. Results showed seed priming increased germination percentage, germination speed, seedling length, root-shoot ratio and decreased mean germination time. The effectiveness of these treatments varied depending on the level of the stress (zero or -8 bar), and the priming condition including temperature, duration, type and osmotic potential of solution. The lower priming duration (ie., 12 and 24 h) improved germination under normal condition, while a higher priming duration (ie., 36 and 48 h) provided more protection when the seeds were exposed to drought stress. In this study, priming with urea had better results than other treatments. Results showed that seed priming with fertilizers might serve as an appropriate treatment for advancing germination under optimum and drought stress conditions.