Evaluation of dormancy breaking treatments for enhanced germination in Cotinus coggygria, Cornus mas and Viburnum lantana seeds

Cotinus coggygria, Cornus mas and Viburnum lantana are among the most important species in Arasbaran forests in Northwest Iran. This study was carried out to determine which pre-treatments should be used to overcome dormancy of the seeds. Pre-treatments applied to the Cotinus coggygria seeds were submersion in concentrated (98%) sulphuric acid for 5, 10 and 30 minutes and cold stratification for 30, 60 and 90 days. Maximum germination (80%) was observed following submersion in concentrated (98%) sulphuric acid for 90 minutes and then cold stratification for 90 days. Increasing the concentration of exogenous gibberellin to 200 ppm improved germination of Cornus mas seeds to 85%; the effect of cold stratification was limited, with 57.5-60% germination after both 45 and 90 days stratification. Laboratory temperature followed by stratification was applied to Viburnum lantana seeds. The stratification did not significantly affect the germination. Laboratory temperature had a significant effect on breaking seed dormancy and promoted germination up to 70% with no cold treatment.