Physiological and morphological characteristics in seedlings of four Bromus inermis ecotypes under drought stress in germinator and greenhouse conditions

Drought has a major influence on morphological and physiological characteristics of plant species. Drought stress has a direct relationship with germination characteristics including germination percentage, seedling length (mm/plant), root to shoot ratio, seedling weight (g), ratio of dry weight to fresh weight of seedlings (g.dfw-1) and seed vigor index (V). In this research, effects of drought stress on these characteristics were examined on four genotypes of Bromus inermis (Alborz 303, Mazandaran 3151, Firozkuh 3966 and Esfahan 200060) under laboratory and greenhouse conditions. In greenhouse experiment, three physiological traits including chlorophyll, carbohydrates and proline contents were measured. Drought treatments included four levels of osmotic potential (0, -0.3, -0.6 and -0.9 MPa) in germinator and four levels of osmotic potential (FC, 25% FC, 50% FC and 75% FC) in greenhouse, made by Poly-Ethylene-Glycol (PEG 6000) solution in laboratory and weighting method in greenhouses, respectively. Results showed that Esfahan (200060) genotype was better than two other genotypes in terms of germination percentage under the two conditions. Increasing drought stress increased proline and carbohydrate and decreased the chlorophyll content.