Bunium persicum is an umbellifer growing wild on mountains of Iran.The species found only in some natural habitate and is not cultivated because their seeds are dormant.Some physical and chemical agents affect germination of seeds and overcome seed dormancy in plants. The purpose of this research was to found fit treatments for breaking dormancy in Bunium persicum seeds. Several methods were used to release of seed dormancy in this study. In one experiment , the effects of different concentrations of potassium nitrate, polyethylen glycol (PEG),thiourea,gibberellic acid(GA3),kinetin(KI) and benzyladenine(BA) on seed germination were studied. Significantly highest germination percentage(G%) (68.7%) was obtained from seeds that exposed to BA(10-5M). In another experiment,seeds were exposed to BA(10-5M) in combination with PEG(3%) , NaEDTA(10-3M) or GA3(10,100mgl-1). Results showed that BA+GA3(10mgl-1) and BA+PEG substantialy decrease dormancy of seeds as respectively 82.8% and 73.4% of seeds subjected to BA+GA3(10mgl-1) and BA+PEG treatments were germinated. In a third experiment, seeds were stratified for 0,4,6,8 and 10 weeks at 4°C then were placed in optimum condition for germinaiton.Increasing the duration of stratification result in a significant increase in G% , with 8 and 10 weeks allowing for 58% germination. In a fourth experiment we investigate the effectiveness of different growth regulators (KI, GA3 and BA ) on germination of 4 weeks stratified seeds . BA (10-5M) treatment had promotive effect on germination of stratified seeds , as 92% of seeds were germinated in this treatment.

Key words: benzyladenine, Bunium persicum, dormancy, stratification