2.1 Study species
Primula vulgaris (primrose) is an ancestrally heterostylous,
diploid (2n=22) perennial, rosette-forming plant blooming from February
to April. Distylous populations of P. vulgaris occur across
Eurasia, including in Turkey, most of Western Europe, larger
Mediterranean Islands, and all British Isles
(Jacquemyn et
al., 2009). In contrast, populations with varying frequencies of
homostyles have been discovered only in Somerset and Chiltern Hills,
England (Crosby, 1940, 1949), and one population in the Netherlands
(Barmentlo et al. , 2017). Habitat fragmentation due to intensive
pastoral and agricultural activities in these areas were suggested as
the potential selective pressure favoring the shift to self-fertilizing
homostyles in these populations (Mora-Carrera et al., 2021).