Variability of in vitro germination of Picea omorika pollen

Serbian spruce (Picea omorika /Panc./Purkyne) is a Balkan endemic and Tertiary relict, therefore it has an exceptional significance from the historical-geographical aspect as well as from the aspect of tree improvement and biodiversity conservation. Pollen was collected from 24 trees in two consecutive years and analyzed once a month. Germination of fresh pollen and pollen stored under different temperatures (room temperature: 23 ±1°C, +4°C, –15°C and –20°C) by in vitro method on a medium with 10% sucrose was analyzed. Fresh pollen germination was 53.63% and 68.06% for pollen collected in first and second year, respectively. After one year of storage at –20°C pollen germination was 22.36% and 60.72%, respectively. The differences between pollen collection years, temperature treatments, storage periods and individuals were statistically significant. Since pollen germination rates of individual trees between the first and the second year showed weak positive correlation, one could conclude that germination of fresh pollen grains is under the certain influence of environmental conditions. It is determined strong positive correlations between fresh and stored pollen at –20°C from both years of pollen collection.