Dormancy breaking in Cotinus coggygria Scop. seeds of three provenances

With the objective of studying the effect of pretreatments involving sulfuric acid scarification, cold moist stratification, and scarification followed by stratification on germination of Cotinus coggygria Scop. seeds of different provenances, fruits were collected in three provenances from Artvin, Turkey. Sulfuric acid was not found an effective scarifying agent for breaking seed coat dormancy in C. coggygria seeds. Germination percentage and germination rate increased significantly with increasing stratification duration (30 to 120 days), with optimum at 120 days for all seed provenances. When averaged over all provenances, cold stratification for 3 months resulted higher germination percentage (GP = 72.3%) and germination rate (PV = 8.2) than that of scarification. Also, germination response for different scarification and stratification treatments revealed a significant difference on germination of the provenances. Seeds scarified with sulfuric acid followed by cold moist stratification showed significant improvement for germination performance. Highest improvement observed under scarification (20 - 40 min) followed by stratification (30 or 60 days) treatments (GP > 90%; PV > 16), and seeds from three provenances exhibited uniformity in response.