Soil Requirements, Genetic Diversity and Population History of the Juniperus sabina L. Varieties in Europe and Asia

Trees and shrubs belonging to the genus Juniperus L. are pivotal species in arid and semiarid ecosystems in the Northern Hemisphere. However, unfavourable phenomena are observed in their populations due to global warming. We aimed to investigate the soil requirements, genetic diversity and population history of Juniperus sabina L. from Europe, Georgia, and Kyrgyzstan. Genetic resources were evaluated in 16 populations using nuclear microsatellites, while past demographic events were described based on the chloroplast DNA haplotypes. Seven chemical parameters in 36 soil samples from the European range of J. sabina were compared. In the studied area, three distinct phylogenetic lineages corresponding to different varieties of J. sabina, namely var. sabina, var. balkanensis, and the Asian variety, were revealed. Unimodal mismatch distributions and significantly negative Tajima’s D and Fu’s Fs parameters indicated that the sabina and balkanensis varieties underwent a population expansion. Microsatellite variation was moderate, potentially influenced by inbreeding, clonal propagation, and limited gene flow between populations. Bayesian clustering revealed five genetic groups. Compared to var. sabina, the balkanensis variety occupies areas with significantly higher potassium content in the soil, which probably mitigates the adverse effects of drought in its localities.