Abstract

The genus Scorzonera L. s.l. encompasses enormous morphological variation and has created problems for taxonomists. Podospermum has been treated as either a section of a broadly defined Scorzonera or as an independ- ent genus. In Italy, there are twelve Scorzonera species and three Podospermum species. The relationship between these species is not at all clear. To clarify these relationships, a survey, including thirteen of the fifteen taxa found in Italy, was carried out using: i) sequence analysis of ribosomal internal transcribed spacer (ITS) and external tran- scribed spacer (ETS) regions; ii) analysis of Amplified Fragment Length Polymorphisms (AFLPs); iii) chromosome counts. In addition, to broaden the scope of the work and allow taxonomically significant interpretation of the data to be made, sequences from a range of related species were obtained from the EMBL nucleotide sequence database. Our analyses clearly indicate that Scorzonera s.l. is a polyphyletic grouping. The three approaches used were consist- ent with each other although showing different levels of resolution. There was broad division, on the basis of chro- mosome number, either 2n = 12 or 14. This was supported by PCO analysis of AFLP fragments which indicate three groups. Finally, phylogenetic analysis of sequence data produced four to six highly supported clades that might ap- propriately be given independent taxonomic status.

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