Intraspecific Genetic Diversity of <i>Cistus creticus</i> L. and Evolutionary Relationships to <i>Cistus albidus</i> L. (Cistaceae): Meeting of the Generations?

• Main Authors: Brigitte Lukas, Dijana Jovanovic, Corinna Schmiderer, Stefanos Kostas, Angelos Kanellis, José Gómez Navarro, Zehra Aytaç, Ali Koç, Emel Sözen, Johannes Novak
• Format: Article
• Language: English
• Published: MDPI AG 2021-08-01
• Series: Plants
• Subjects: <i>Cistus</i>; <i>Cistus creticus</i>; genetic diversity; ITS; Mediterranean; phylogeography
• Online Access: https://www.mdpi.com/2223-7747/10/8/1619

<i>Cistus</i> (Cistaceae) comprises a number of white- and purple-flowering shrub species widely distributed in the Mediterranean basin. Within genus <i>Cistus,</i> many taxa are subject to various taxonomic uncertainties. <i>Cistus creticus</i>, a prominent member of the purple-flowered clade, is a prime case of the current taxonomic troubles. Floras and databases approve different species names and utilise different or additional/fewer synonyms. Various intraspecific classification systems based on subspecies or varieties are in use. The inconsistent determination of plant material makes it difficult to compare literature regarding the phytochemical diversity and biological activities of plant material and impedes a systematic utilization of the manifold medicinal properties of <i>C. creticus</i>. In the present investigation, we used DNA sequence data from one nuclear region (ITS) and two chloroplast regions (<i>trnL-trnF</i>, <i>rpl32-trnL</i>) to test the intraspecific genetic diversity of <i>C. creticus</i> and its evolutionary relationships to the closely related <i>C. albidus</i>. The combined DNA data confirmed <i>C. creticus</i> as a rather heterogeneous species that integrates two major evolutionary lineages with clearly different genetic characteristics. The ‘Eastern Mediterranean clade’ seems to represent old and ancestral characteristics. This lineage exhibits a close relationship to the geographically distant <i>C. albidus,</i> expressed by very closely related ribotypes and an interspecifically shared chlorotype. The ‘Western Mediterranean clade’ is characterized by a distinctive ITS polymorphism (co-occurring paralogous ribotypes) and more distantly related chlorotypes. The formation of the genetically complex ‘Western Mediterranean clade’ seems to have involved hybridization and recurrent formation or migration movements.