Effects of cold stratification and sulphuric acid pretreatments on germination of three provenances of smoke-tree (Cotinus coggygria Scop.) seeds in greenhouse and laboratory conditions

Abstract

This study was carried out to determine which pre-treatments should be preferred to overcome dormancy problems of Cotinus coggygria seeds which were collected from three different provenances. Pre-treatments applied to the seeds were submersion in concentrated (98%) sulphuric acid (10, 20, 30, 40 and 50 min) and submersion in sulphuric acid (10, 20, 30, 40 and 50 min) followed by cold stratification (15, 30, 45 and 60 days). The seeds were sown in polyethylene pots in the greenhouse and sown at 22 ± 1°C under darkness in laboratory conditions. The statistical approach was a randomized complete block design with 3 replications. Germinated seeds were observed periodically for 50 days to determine germination percentages and germination rates. Submersion in H2SO4 for 50 min with cold stratification for 15 days gave the highest germination percentage (88.1%) in the laboratory while, while the highest germination percentage (70.2%) was obtained from submersion in H2SO4 for 10 min with cold stratification for 30 days pre-treatment in the greenhouse. The analyses also revealed that the seeds collected from Ardanuc resulted in the highest germination percentage value (44.6%) in the laboratory among the provenances. The highest germination percentage (53.2%) sown in the greenhouse conditions was determined from the seeds collected in Artvin.