Clarifying genetic and taxonomic relationships among Pistacia taxa (Anacardiaceae) in Croatia

Abstract

In the eastern Adriatic flora the genus Pistacia L. (Anacardiaceae) is represented with P. lentiscus L., P. terebinthus L., their hybrid P. × saportae Burnat and the cultivated P. vera L. In addition, an endemic putative taxon from Mt. Biokovo was described in 1985 as P. calcivora Radić. Our aim was to resolve relationships between the four putative indigenous taxa of this genus in Croatia (P. lentiscus, P. terebinthus, P. × saportae and P. calcivora) based on genetic (AFLP) and morphological data. Specifically, we aimed to determine the presence of the hybrid taxon P. × saportae and to validate the controversial taxonomic status of P. calcivora at the molecular and morphological levels. Our combined results indicate the presence of two well separated groups of populations. The first group included all individuals of P. terebinthus and the individuals initially assigned to the potential taxon P. calcivora based on leaf morphology, suggesting that there is no support for the described taxon P. calcivora and that it should be considered as a synonym for P. terebinthus. The second group corresponded to P. lentiscus and included the majority of the presumed hybrid individuals of P. × saportae. However, four hybrid individuals were confirmed at the molecular level and were placed between the two parental taxa in the phylogenetic tree, confirming the presence of P. × saportae in Croatia. Although confirmed P. × saportae individuals were genetically closer to P. lentiscus, they were morphologically more similar to P. terebinthus, hindering their correct identification in the field.