Mojtaba Soleimani Sardo

In forage grass species, germination is one of the important stages in growing stage that is often influenced by environmental stresses particularly salinity and drought stresses. Thus, the purpose of this study was assessment the effects of salinity and drought stresses on germination characteristics and seedling growth of desert wheatgrass Agropyron desertorum (Fisch. ex Link) Schult under laboratory conditions. Two separate experiments were conducted using completely randomized design with four replicates. Six salinity treatments (control, 50, 100, 150, 200 and 300 mM NaCl) and six drought treatments (control, -0.2, -0.4, -0.6, -0.8 and -1 MPa polyethylene glycol) were used in four replicates. Germination percentage and rate were calculated by computation of germinated seeds every day. Growth parameters (rootlet, shoot and seedling length), allometric index and seed vigor were obtained accordingly. For each experiment One-way ANOVA was used to determine significance effects of treatments and mean comparison were made using Duncan method using SPSS software. Results showed that salinity and drought stresses had the significant effects on germination and growth indices of Agropyron desertorum so that germination rate, germination percentage, root length, shoot length, seedling length and seed vigor indices were decreased by increasing the concentration of different salinity and drought treatments. Also, seed germination and growth was observed only until -0.4 MPa drought level, so that germination at Ψs = -0.6 MP was completely stopped.