WHEAT PHYLOGENY DETERMINED BY RFLP ANALYSIS OF NUCLEAR-DNA .1. EINKORN WHEAT

To obtain new information on the phylogenetic relationships between wild and cultivated einkorn wheats and their relation to polyploid wheats, we made restriction fragment length polymorphism (RFLP) analyses of the nuclear DNAs of diploid and polyploid wheats. Two to three accessions of three einkorn species, Triticum boeoticum and T. urartu (both wild), and T. monococcum (cultivated), and a single accession each of emmer and common wheats were used. Forty-six DNA clones known to hybridize the DNA of the A genome chromosomes were selected from the genomic library of common wheat and used as probes in Southern hybridization of the total DNAs of all above accessions which were digested with BamHI or HindIII. Genetic distances were calculated between all the pairs of accessions from RFLP data obtained from 88 probe-enzyme combinations, clustering being obtained by the UPGMA method. All the accessions of T. urartu, T. durum and T. aestivum were clustered in one group. Those of T. boeoticum and T. monococcum were in a different group. We conclude that T. monococcum is derived from T. boeoticum and that the A genomes of the emmer and common wheats originated in T. urartu.