Research Highlights: The effects of climate change on habitat loss, range shift and/or genetic impoverishment of mid-elevation plants has received less attention compared to alpine species. Moreover, genetic diversity patterns of mountain forest herbaceous species have scarcely been explored in the Balkans. In this context, our study is the first that aims to examine Helleborus odorus subsp. cyclophyllus, a medicinal plant endemic to the southern part of the Balkan Peninsula. Background and Objectives: We compare its genetic diversity and structure along the continuous mountain range of western Greece with the topographically less structured mountains of eastern Greece, and predict its present and future habitat suitability, using several environmental variables. Materials and Methods: Inter Simple Sequence Repeat (ISSR) markers were used to genotype 80 individuals from 8 populations, covering almost the species’ entire distribution range in Greece. We investigated the factors shaping its genetic composition and driving its current and future distribution. Results: High gene diversity (0.2239–0.3319), moderate population differentiation (0.0317–0.3316) and increased gene flow (Nm = 1.3098) was detected. According to any GCM/RCP/climate database combination, Helleborus odorus subsp. cyclophyllus is projected to lose a significant portion of its current distribution by 2070 and follow a trend towards genetic homogenization. Conclusions: Populations exhibit in terms of genetic structure a west–east genetic split, which becomes more evident southwards. This is mainly due to geographic/topographic factors and their interplay with Quaternary climatic oscillations, and to environmental constraints, which may have a negative impact on the species’ future distribution and genetic composition. Pindos mountain range seems to buffer climate change effects and will probably continue to host several populations. On the other hand, peripheral populations have lower genetic diversity compared to central populations, but still hold significant evolutionary potential due to the private alleles they maintain.

In this study, we present an overall phylogenetic framework for Dianthus using four plastid regions (matK-trnK-psbA, rpl32-trnL, trnQ-rps16) and nuclear ITS and a species-level checklist for the genus developed by using all available databases and the literature. The trees from the plastid dataset depict a clade of Dianthus that also includes Velezia and a few taxa of Petrorhagia. New combinations in Dianthus are provided for these species. The checklist of Dianthus in this new delimitation covers 1781 names, with 384 accepted species, 150 subspecies, 12 heterotypic varieties and two forms (not counting autonyms), 1050 synonyms, 22 hybrid names and 172 unresolved names, 3 names were excluded. Implications for the evolution of flower characters, life forms, biogeography, as well as sectional classification are discussed based on the phylogenetic framework.

The genetic diversity of 27 garlic accessions (local varieties/landraces) was investigated using five simple sequence repeat (SSR) and six inter-simple sequence repeat (ISSR) markers. The SSR genotyping revealed 26 different alleles, while 84 polymorphic bands were produced using the ISSR markers. The average polymorphism information content (PIC) was 0.471 and 0.465 for the SSR and the ISSR markers, respectively. Compared to ISSRs, SSR markers revealed a higher level of redundancy, indicating potential duplicates among the accessions. The analysis of molecular variance (AMOVA) based on both marker systems showed that most of the molecular diversity was attributable to differences within accessions, rather than among them. UPGMA, STRUCTURE, and Principal Coordinate Analysis (PCoA) based on the SSRs produced similar clustering results, although not in agreement with those produced by the ISSR markers. Fisher’s exact tests and multinomial logistic regression analyses identified significant associations between the chemical compounds, the morphological traits of the bulb, and specific SSR and ISSR loci. Our results provide a molecular basis for understanding the genetic diversity of Greek garlic landraces, which could be useful for the conservation and sustainable management of this crop. Potential markers fostering the selection of genotypes in garlic breeding have also been revealed.