Chitosan Seed Priming Improves Seed Germination and Seedling Growth in Wheat (Triticum aestivum L.) under Osmotic Stress Induced by Polyethylene Glycol

Effects of seed priming with chitosan on seed germination and seedling growth in wheat under osmotic stress induced by polyethylene glycol (PEG-600) were investigated. Seed priming treatments included hydropriming (soaking seeds in aerated distilled water for 8 h) and chitosan priming (soaking seeds in an aerated solution of 0.10%, 0.25% and 0.50% chitosan for 8 h). Seeds were germinated under osmotic stress induced by 15% PEG-6000 (-3 MPa). The final germination percentage (FGP) was substantially increased (95%) by chitosan priming treatments compared with the control (80%). It also reduced (74-70 h) the mean germination time (MGT) of the seeds up to 4 h. Under these circumstances, germination energy, vigor and germination index were markedly improved. All chitosan-priming treatments efficiently improved germination rate, and shoot and root length. Hydropriming also reduced the MGT of seeds along with an increase in germination rate of seeds compared with the control. However, it was unable to improve the FGP, germination energy and index, root and shoot lengths and vigor index. The observed enhancements in seed germination and seeding growth were due to chitosan priming, and not only because of seed soaking. Chitosan seed priming enhanced seed germination and seedling growth in wheat under osmotic stress, resulting in improved tolerance.