تاثیر پیش تیمار بر بنیه اولیه بذر استبرق ) (Calotropis procera L.

• Abstrct:Calotropis procera L. (Asclepiadaceae) is a adapted industrial perennial shrub to arid and semi arid lands . Calotropis sp produces lots of seeds. Nonetheless, its density is very low. To study the effect of pretreatment on early vigor of Calotropic procera L., an experiment was arranged base on randomized completely design with five replications. The used treatments were including different levels of PEG (0, -0.7, -0.9 bar). Results showed, increasing levels of pretreatment from 0(control) to -/7 bar increased germination percentage, shoot and root length seedling dry weight significantly. The greatest increase was observed in the characteristic length, Using pre-treatment can increase early vigor of Calotropic procera seeds and increased density it’s in arid and semiarid regions