-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 independent 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 transcribed 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 consistent with each other although showing different levels of resolution. There was broad division, on the basis of chromosome 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 appropriately be given independent taxonomic status.

In a study on chromosome banding in species of Tragopogon L. and in Geropogon glaber L., two members of the Scorzonerinae subtribe, the existence of a distinctive pattern of quinacrine bands consisting of clusters of dots displaying bright fluorescence was discovered (D,AMATO et al. 1975). The pattern was characteristic for each species analysed, moreover a different heterochromatic "structure" characterized the two genera (in Geropogon there were also regions of dim fluorescence and the bright spots were less definite than in Tragopogon). A model of a disrupted banding pattern was proposed.After the application of Giemsa C-banding to Tragopogon and Geropogon chromosomes, no cluster bands were observed, while the Feulgen banding affected their differentiation, although to a limited extent (D'AMATO 1986).In the present report, two species of Scorzonera L. i.e.: S. rosea W. et K. and S. cana (C.A. Meyer) 0. Hoffm. were tested by fluorochrome banding, to verify if the unusual heterochromatic band appearance could represent a karyotype marker of this group of plants. Both species are included in the same genus, but in separate subgenera, by CHATER (1 976), while the Italian Flora published by PIGNATTI (1982) considers S. cana as a member of a distinct genus: Podospermum. However the genus Podospermum is not recognized by BREMER (1994) who reports seven genera and about 300 species in this subtribe. MATERIAL AND METHODSSamples of S. rosea were collected in Central Italy at Forca Canapine, near Norcia (Perugia). Plants of S. cana were collected at Lucoli (L'Aquila). All the specimens were cultivated in pots.Root tips pretreated in a 0.3% colchicine solution for three hours and fixed in ethanol-acetic acid (3:l) mixture overnight were then squashed in 45% acetic acid and the slides after removing the coverslip with dry ice were analized after fluorochrome treatment either in 5% ethanol solution of quinacrine dye or after DAPI/chromomycin A, double staining according to SCHWEIZER (1976).The ideogramatic representation of S. rosea was obtained by measurements of six metaphase plates of Feulgen stained meristematic cells. OBSERVATIONS AND DISCUSSIONBoth the species analized showed a chromosome number 2n = 14, but the karyotype structure was different. According to the nomenclature of LEVAN et al. (1965), S. rosea had the following karyotype: 8 m + 2 m sat + 2 sm + 2 sm sat + 2 st. In S. cana the karyotype formula was: 6 m + 2 m sat + 4 sm + 2 st. In this last plant, two large satellites were observed. The quinacrine staining of S. rosea metaphases revealed a speckled heterochromatin pattern in almost all the chromosomes of the set. In one pair only (the pair number 2, in Fig. 7; and in Fig. 4, the chromosomes at the top right-and left-hand corners), the heterochromatic region consisted of a thin faintly visible and apparently linear band on both arms. The rest of the chromosomes were characterized by a series of dots clustered near the centromere or distributed mainly in one of the two arms (Fig. 1, Fig. 4). An ideogramat...