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 chlor oplast DNA of Aristavena setacea, Deschampsia cespitosa, D. media, Ave nella flexuosa and A. stricta, which had been previously considered as belonging to the genus Deschampsia BEAUV. s. 1., in order to determin e their taxonomic relationships. The results obtained with these diffe rent approaches indicate that Avenella diverges substantially in all c haracters analyzed from the other two genera. No differences in six ch loroplast DNA segments analyzed were found between Aristavena and Desc hampsia, which also show a level of total genomic DNA hybridization th at indicates a relatively high proportion of common sequences. The clo ser relationship of these two genera contrasts with their divergence i n karyotype structure that suggests a possible allopolyploid origin of Deschampsia.