A phylogenetic investigation of Carthamus combining sequence and microsatellite data

Carthamus (Asteraceae) includes both crop (Carthamus tinctorius, safflower) and weedy species. Despite previous studies, many outstanding questions remain regarding the phylogenetic surroundings of safflower, especially in relation to weedy species. Here we investigated relationships within Carthamus using a tiered approach examining sequence and microsatellite data. First, nuclear and chloroplast sequences were analyzed from 37 accessions of 16 species. Maximum parsimony, maximum likelihood, and Bayesian inference confirm two well supported clades, corresponding to sect. Atractlyis and sect. Carthamus, the latter of which includes safflower. Because sequence data provided limited resolution within the clades, microsatellite markers were used to investigate relationships within sect. Carthamus. Both sequence and microsatellite data reveal that most traditionally recognized species are not monophyletic. Microsatellite data indicate that Carthamus palaestinus is the closest relative of cultivated safflower.