The assessment of genetic diversity and population structure of endemic Scutellaria yildirimlii (Lamiaceae) for conservation purposes

Scutellaria yildirimlii is an endangered perennial endemic species from Turkey and belongs to the family Lamiaceae, which has a high number of medicinal and aromatic plants. It is crucial to determine genetic diversity and population structure of this species for its conservation measures; therefore, 111 individuals from five natural populations of S. yildirimlii were investigated by using 15 inter simple sequence repeats (ISSR) primers. The percentage of polymorphic loci (PPL), Nei's gene diversity (H), and Shannon's information index (I) at the species and population-level were determined as 93.9%, 0.183, 0.292 and 56.5%, 0.158, 0.242, respectively. The analysis of molecular variance (AMOVA) showed that there is more genetic variation within populations (84%) than among populations (16%). Nei's differentiation coefficient (GST = 0.144) was determined to be moderate, which was confirmed by the level of genetic differentiation among populations. Gene flow (Nm = 2.984) showed high genetic exchange among populations. Pairwise genetic distance values among populations ranged from 0.0219 to 0.0512. The Mantel test revealed a statistically significant positive correlation between genetic and geographical distance (r = 0.493, p < 0.001). The Unweighted Pair Group Method with Arithmetic Averages (UPGMA) dendrogram and Principal Coordinate Analysis (PCoA) showed similar results. STRUCTURE analysis (Delta K = 3) revealed that the K test yielded maximum peaks for 3 clusters. Based on the findings, measures for genetic conservation and management of this species were presented.