The effect of pre-treatments and seed collection time on the germination characteristics of common hornbeam (Carpinus betulus) seeds in the Eastern Black Sea Region, Turkey

The germination characteristics of common hornbeam (Carpinus betulus), which shows a natural distribution in Turkey, were analysed. Seeds were obtained from 12 populations at different altitudes in the river basins of Trabzon-Maçka, Trabzon-Çaykara, Rize-Çamlıhemşin and Giresun-Espiye. In common hornbeam seeds, there is a germination barrier caused by the seed coat and embryo. In order to eliminate the germination barrier and increase germination, 22 different pre-treatments, including control different concentrations of GA₃, citric and sulphuric acids, and different stratification periods were performed before seed germination was tested. Analysis of the effect of different seed collection times and pre-treatments on the germination percentage revealed differences according to population and altitude. The pre-treatments also showed differences on the basis of populations. The highest germination took place following GA₃ pre-treatments (30%) and in seeds collected in mid-September (54%).