GIS Bioclimatic Profile and Seed Germination of the Endangered and Protected Cretan Endemic Plant Campanula cretica (A. DC.) D. Dietr. for Conservation and Sustainable Utilization

This study focused on the seed germination of the local Cretan endemic Campanula cretica, an endangered and nationally protected species with ornamental value. To determine its seed germination requirements, high-resolution bioclimatic (temperature and precipitation) maps were integrated with geographic distribution data of C. cretica using Geographic Information Systems. The seed germination was tested at four constant temperatures (10, 15, 20, and 25 °C) with a photoperiod of 12 h light/12 h dark and under light/darkness and darkness at 15 °C. Pre-treatments with gibberellic acid solutions (500 and 1000 mg·L−1 GA3) and cold moist stratification at 5 °C were applied to investigate seed dormancy. Seed germination was significantly affected by the interaction of temperature and seed pre-treatments; without pre-treatment, the seeds germinated better (>85%) at 10 and 15 °C. The detected seed germination pattern matched the natural temperatures prevailing in situ during late autumn. Pre-treatments with GA3 solutions and cold stratification first reported herein widened the seed germination range at 20 and 25 °C. The seeds germinated better in light (94.38%) than in darkness (69.38%). The results of this investigation addressed existing research gaps (GIS-derived bioclimatic profiling, effects of incubation temperature, cold stratification, GA3, and light investigated for the first time), thus facilitating species-specific conservation efforts and enabling sustainable utilization strategies.