Effect of scarification, cold and after-ripening treatments on seed dormancy breaking in four species of Satureja by standard germination test

In order to study the dormancy breaking ways and germination enhancment, seeds of 8 ecotypes of 4 species Satureja sahendica Bornm., S. bachtiarica Bunge, S. khuzistanica Jamzad and S. hortensis L. were collected on the base of geographycal distributions. A factorial experiment based on completely randomised design with three replications were used. The different treatments including: cold stratification, after-ripening, physical scarification (sand paper), chemical scarification (Ethylic alcohol 70%) and control were used for dormancy breaking. The treated seeds were sown in 3 petri dishes as replications. Then, all samples were placed in a germinator with condition of 20°C and light-to-dark cycle of 16 hours light (1000 lux) to 8 hours dark. The germination characteristics including: germination percentage, speed of germination, length of root and shoot, vigour index, fresh weight and dry weight were evaluated during 18 days of the experiment. There were significant differences amoung species for all seed germination characteristics. The ecotype of Khuzistan from S. khuzistanica had more seed germination and vigour compared to the other three species. The seed characteristics specially speed of germination and vigour index of ecotypes from cold zone were affected by cold treatment more than the other treatments.