Effect of Different Osmotic Potentials of Media on Germination of Three Safflower Varieties

The effect of osmotic potentials, 0 to ?13.5 atm (?1.37 M Pa), on the germination of three safflower varieties (Carthamus tinctorius L.) was studied at a controlled temperature (30±2°C) using a non-electrolyte substance, polyethelene glycol 6000. The varieties were cv. Ute, cv. Iranian local 3151, and cv. Iranian local 2811. The percent germination of the three varieties averaged over all osmotic potentials were: 86, 77 and 61 for local 3151, local 2811 and “Ute”, respectively. The Ute variety had the highest, and the local 3151 variety had the lowest rate of germination reduction. The variations among the varieties in the percent and rate of germination were due to osmotic effects of the media.