-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.
The two taxa, Narcissus poëticus and N. radiiflorus, although apparently quite morphologically distinct, grow together and there has been some debate as to whether they should be considered as a single or two separate species. In order to throw some light on this debate, a survey of amplified fragment length polymorphism (AFLP) was conducted to examine genetic diversity/similarity among 120 individuals of N. poëticus and N. radiiflorus obtained from two populations coming from sites separated by more than 100 km. In addition, a karyological study of the two taxa was carried out to determine chromosome number and morphology, the number of nucleoli and banding pattern with the fluorochromes chromomycin A 3 and DAPI. Using two AFLP primer pairs, a total of 103 clearly scorable fragments were amplified; of which 91 (88%) were polymorphic (78% if polymorphism is described as the most common band not present in more than 95% of individuals sampled). Cluster analysis and principal coordinates analysis of the calculated similarity matrix revealed there to be only a low level of genetic diversity between the entities constituting the populations and species. The genetic distance between the individual belonging to the different populations of the same species was slightly greater than that between species. Comparative chromosome analysis showed no differences in the two taxa at the cytological level.
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