Molecular markers in the detection of interspecies hybridization – a model study on the genus Centaurium Hill

Abstract

The species of the genus Centaurium Hill are characterized by a pronounced phenotypic plasticity, while interspecific hybridization readily occurs. Previous studies reported hybridization events between C. erythraea and C. tenuiflorum in the Mediterranean region, but the status of a potentially hybrid taxon (termed "Centaurium ×tenuiflorum") remains unclear. Therefore, molecular markers (EST-SSR, ITS, and chloroplast DNA markers) were combined and their usefulness in estimating overall genetic variability and in identifying phylogenetic relations between Centaurium taxa was scrutinized. Both EST-SSR and ITS markers proved to be well suited to distinguish the parental taxa C. erythraea and C. tenuiflorum, and a putative hybridogenic taxon "C. ×tenuiflorum", the last one being more related to C. erythraea. Conversely, maternally inherited chloroplast markers (trnL-F, rbcL and psbA-trnH) nominated C. tenuiflorum as a donor of plastid.