COMPARATIVE-ANALYSIS OF GENETIC-RELATIONSHIPS IN BARLEY-BASED ON RFLPAND RAPD MARKERS

Genetic relationships have seldom been analyzed with different types o f molecular markers in order to compare the information provided by ea ch marker class. We investigated genetic relationships among nine barl ey cultivars using separate cluster analyses based on restriction frag ment length polymorphisms (RFLPs) and random amplified polymorphic DNA s (RAPDs). Genomic DNA restricted with three enzymes and hybridized wi th 68 probes revealed 415 RFLPs (74.2% of all bands). Among the 128 pr imers used for RAPD analysis, 100 provided a reproducible profile, 89 of which revealed 202 polymorphic and 561 monomorphic bands (26.5 and 73.5%, respectively). A nonrandom distribution of 62 RAPDs with a tend ency to cluster near centromeric regions was produced when these RAPDs were mapped using 76 doubled-haploid lines derived from a cross betwe en two of the nine cultivars. The correlation between the RFLP and RAP D similarity matrices computed for the 36 pairwise comparisons among t he nine cultivars was equal to 0.83. The dendrograms obtained by clust er analyses of the RFLP and RAPD data differed. These results indicate that in barley the information provided by RFLPs and RAPDs is not equ ivalent, most likely as a consequence of the fact that the two marker classes explore, at least in part, different portions of the genome.