Diversity and systematics of Deschampsia sensu lato (Poaceae), inferred from karyotypes, protein electrophoresis, total genomic DNA hybridization and chloroplast DNA analysis

We have analyzed the C-banding karyotypes, electrophoretic mobility of isozymes and seed proteins, total genomic DNA hybridization and chloroplast DNA of Aristavena setacea, Deschampsia cespitosa, D. media, Avenella flexuosa and A. stricta, which had been previously considered as belonging to the genus Deschampsia Beauv. s. l., in order to determine their taxonomic relationships. The results obtained with these different approaches indicate that Avenella diverges substantially in all characters analyzed from the other two genera. No differences in six chloroplast DNA segments analyzed were found between Aristavena and Deschampsia, which also show a level of total genomic DNA hybridization that indicates a relatively high proportion of common sequences. The closer relationship of these two genera contrasts with their divergence in karyotype structure that suggests a possible allopolyploid origin of Deschampsia.