CONSTRUCTION OF A RESTRICTION-FRAGMENT-LENGTH-POLYMORPHISM MAP FOR BARLEY (HORDEUM-VULGARE)

A restriction fragment length polymorphism (RFLP) map for barley (Hordeum vulgare L.) has been developed on the basis of a population of anther culture derived, doubled haploids from the F1 of cultivars 'Proctor' x 'Nudinka'. Wheat genomic, oat cDNA, and barley cDNA clones provided the major source of the probes. Additional clones included genomic clones from Aegilops squarrosa L. and barley, two dehydrin genes, a barley promoter, and a wheat ribosomal gene. In total, 155 RFLPs and two known genes (hulless and Mla12 powdery mildew resistance) have been placed on the linkage map. Clones were assigned to chromosomes using disomic wheat-barley chromosome addition lines. Chromosome arm orientation was done using 'Chinese Spring' wheat nullisomic-tetrasomic and ditelosomic aneuploid stocks. Markers have been located on all chromosome arms except 6S, and the total map length is 1096 centimorgans (cM). Considerations involved in RFLP mapping, including choice and number of restriction endonucleases, disturbed segregation ratios, and uneven distribution of markers in the genome are discussed as well as future improvements and applications of this map.