Effect of drought stress on seed germination and some morphopysiological and biochemical traits of Oryza sativa L. cv. Hashemi seedlings

Two separate experiments were carried out with the aim of investigating the effect of drought stress on of germination, morphological and biochemical traits of Oryza sativa L. cv.Hashemi in vegetative growth at the Research Center for Plant Sciences, Ferdowsi university of Mashhad, in 2011. At first experiment, different level of drought stress (0, -2, -4, -6, -8, -10 bar) by polyethylenglycol 6000 were studied on germination of rice. The number of germinated seeds was counted each day and was sampled after ten days. Then, the percentage and rate of germination and length and dry weight of shoot and root were determined. The next experiment, levels of drought stress including control (field capacity), 20, 40, 60, 80 of field capacity on vegetative growth rice plantlets were investigated. Plantlets were transferred to the plastic pots and the sampling of seedlings was carried out 22 days after planting. Both experiments were conducted in Completely Random Design with three replications. The results showed that levels of drought had a negative effect on the percentage and rate of germination and length and dry weight of shoot and root. In vegetative stage, height, leaf area and root only in 20% field capacity treatment and amount of prolin and potassium in shoot in all drought levels were significantly decreased. We concluded the level of drought stress in 40, 60, 80 field capacity have not sensible effect on vegetative growth Oryza sativa L. cv.Hashemi.