Microsatellite markers as a useful tool for species identification and assessment of genetic diversity of the Tilia species in the Czech Republic

Diagnostic morphological traits distinguishing <i>Tilia cordata</i> and <i>T. platyphyllos</i> are not always apparent. Precise species identification iscrucial for conservation management and for establishing genetic resources offorest reproductive material. Inthis study, weemployed fifteen microsatellite (SSR) markers toidentify diagnostic loci for reliable species discrimination between <i>T. </i><i>cordata</i> and <i>T. platyphyllos</i> species and toevaluate the genetic diversity. Atotal of250 trees were sampled from eight natural autochthonous populations of<i>T. cordata</i> and <i>T. platyphyllos</i> inthe Czech Republic, and additional ten individuals of<i>T. tomentosa</i> were included for comparison. Markers Tc8 and Tc918 were identified asdiagnostic, exhibiting species-specific alleles for <i>T. cordata</i> and <i>T. platyphyllos</i>. Contrary tothe previously published results, weobtained PCR amplicons atlocus Tc918 with anallele size of226 bp in<i>T. cordata</i>. Ananalysis ofthe fifteen SSR loci revealed ahigh level ofgenetic variability inboth the <i>T. cordata</i> and <i>T. platyphyllos</i> populations. Noclonally identical genotypes were detected across the eight study sites. The genetic differentiation (Fst) was higher between <i>T.</i> <i>platyphyllos</i> and <i>T. tomentosa</i> (0.316) than between <i>T. platyphyllos</i> and <i>T. cordata</i> (0.205). Bayesian clustering further revealed distinct genetic structures for <i>T. cordata</i>, <i>T. platyphyllos</i>, and <i>T. tomentosa</i>.