Full Length Research Paper

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

Z. Olmez*, A. Gokturk, B. Karasah and H. Yilmaz

Artvin Coruh University, Faculty of Forestry, 08000 Artvin Turkey.

*Corresponding authour. E-mail: zaferolmez@yahoo.com. Fax: +90 4662126951.

Accepted 6 August, 2009

   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 Ardanuç 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.

Key words: Cotinus coggygria, germination, pre-treatments, seed dormancy.