Document Type : Research Paper
Assistant Professor, Research Institute of Forests and Rangelands, Tehran, Iran
Professor, Faculty of Natural Resources, University of Tehran, Karaj, Iran
Physiological effect of six levels of water stress (0, -0.1, -.03, -0.6, -0.9 and -1.2 MP) was studied on seed germination and plumule as well as radicule growth length in three species namely: Agropyron elongatum, Agropyron desertourm and Secale montanum. Polyethylene glycol (PEG) was used to provide appropriate water potentials. A total of 100 seeds in four replications (Petri dishes) were sown from each species. Experimental design was a factorial one of complete randomized design. Maximum germination rate was obtained at 0 MP. Germination rate and plumule and radicule growth declined with water potential level. The most resistance species to water stress are Secale montanum, Agropyron elongatum and Agropyron desertorum respectively.