Comparison of restriction fragment length polymorphisms in wild and cultivated barley

This study was undertaken to assess the relative level of molecular diversity between cultivated barley, Hordeum vulgare ssp. vulgare (HV), and one of its wild relatives, H. vulgare ssp. spontaneum (HS), and to identify possible restriction fragment length polymorphism (RFLP) patterns that may provide information concerning the phylogenetic relationship between these two barley groups. A total of 363 barley accessions were assayed, including 95 entries of HV collected from 36 major barley growing countries of the world and 268 entries of HS from 25 natural populations in Israel and Iran. The 26 RFLP marker loci used in the survey represent single-copy, low-copy, and repetitive DNA sequences and mark all of the chromosome arms. A randomization test, on the basis of equal sample sizes, showed that HS is more polymorphic than HV, as evaluated by the number of alleles and diversity indices. The analysis also indicated extensive RFLP differentiation between these two barley groups; highly significant differences of allele frequencies were detected at the majority of the loci. The HV sample can be subdivided according to winter or spring growth habits, and two- or six-rowed spikes. Analysis of genetic polymorphisms in these subgroups showed that levels of diversity were about equal in spring and winter groups and also in the groups with two- and six-rowed spikes. However, significant differences of allelic frequencies were detected between subgroups of the two divisions.