Systematic status and phylogenetic relationships of the enigmatic Tanacetum paradoxum Bornm. (Asteraceae, Anthemideae): evidences from nrDNA ITS, micromorphological, and cytological data

摘要

In order to evaluate the phylogenetic relationships and taxonomic classification of the Iranian endemic Tanacetum paradoxum Bornm. (Asteraceae, Anthemideae), a molecular analysis based on nrDNA ITS sequences of 16 species of Tanacetum together with representatives of 27 genera of subtribes Artemisiinae and Handeliinae as well as a micromorphological study of achenes and pollen grains was performed. The chromosome number of 2n = 2x = 16 and the genome size of T. paradoxum (2C = 8.81 ± 0.19 pg) are reported here for the first time. Due to the well-supported close phylogenetic relationship of T. paradoxum to the species of the genus Artemisia (Bayesian inference, posterior probability PP = 1), which is supported by cytological (x = 8) and micromorphological features concerning the achene shape and pollen type, the combination Artemisia paradoxa (Bornm.) Sonboli is proposed.