Iranian Journal of Applied Ecology

Detection of effective germination factors on valuable rangeland species is essential in rangelands rehabilitation and restoration projects. This study evaluates the effects of physiological drought stress induced by Poly Ethylene Glycol 6000 (PEG) and alternative temperature on germination percentage and germination speed of Hedysarum criniferum Boiss, a valuable native legume in summer highland pastures of Iran. The experiment was conducted as a completely randomized design using factor analysis, including two factors; two alternative temperature levels (18-20 ^°C and
24-26 ^°C day-night) and four drought levels (0, -2, -4, and -6 bar) with three replications. According to the results, different levels of drought stress and alternative temperature had significant effects on germination percentage and germination speed of the species seeds (α=5%). The study showed that increasing temperature and drought levels leads to reducing the germination percentage and germination speed of the species. Higher germination percentage of H. criniferum seeds in different drought levels compared to alternative temperature levels of 24-26 ^°C indicated that this species is more sensitive to higher temperature than high levels of drought condition. Therefore, it could partly be concluded that the H. criniferum is a relatively drought resistance species.