Regional Variation in Seed Germination and Dormancy of Juniperus foetidissima Willd. in Azerbaijan

Seeds of Juniperus foetidissima are vulnerable to germination depending on the environmental conditions such as temperature, elevation, soil conditions, etc. The inhibition of germination may also be species specific and result from dormancy mechanism. Seeds from four ecological zones of the Republic of Azerbaijan were subjected to warm-cold stratification in order to improve their germination rate. The these areas comprised the Greater Caucasus on the northern slopes, the Lesser Caucasus, Talysh Mountains with the Lankaran–Lerik area, and the Nakhchivan Autonomous Republic. The collected seeds were placed under warm and moist conditions at the temperature of 20-22°C for 4 weeks and then under cold-moist conditions at 4-5°C for 10- 12 weeks. The results showed that seed source and stratification treatments had significant effects on the germination rate. Among the various regions, seeds from the mountainous regions above 1,000 m had the best germination percentages under normal conditions, particularly those from the Lesser Caucasus and Nakhchivan Autonomous Republic. These seed lots, after a combined warm–cold stratification treatment, showed significantly improved germination, with a clear dependence on dormancy-breaking treatments. Plants from high mountain areas usually have a higher germination rate since they experience a natural long stratification period. Lower germinating rates are observed with seeds from lower elevations (Talysh region (Lankaran–Lerik)) even after stratification. This difference is mostly attributable to genetic adaptation to the local climate, which is not as cold as in other parts of the world where it is more important.