C. Pedersen et al., TOWARDS AN INTEGRATION OF THE PHYSICAL AND THE GENETIC CHROMOSOME MAPS OF BARLEY BY IN-SITU HYBRIDIZATION, Hereditas, 123(1), 1995, pp. 77-88
The relationship between physical and genetic distances on the barley
chromosomes was studied by fluorescence in situ hybridization (FISH).
Physical mapping of low- and single copy genes by FISH includes the pr
otein Zx gene on chromosome 4 (4I), the alpha-amylase, high pI, genes
on chromosome 6 (6I), the early-methionine-labelled polypeptide gene(s
) on chromosome 5 (1I), and the leaf thionin genes on chromosome 6 (6I
). Two interstitial sites of the telomere-associated sequence, the HvR
T-family, were mapped by FISH on chromosome 3 (3I), and hybridization
sites of histone 4 and ubiquitin genes were detected on chromosomes 1
(7I) and 5 (1I), respectively. In addition, a 5SrDNA locus was mapped
genetically on chromosome 1. The study provides seven new anchor sites
for integrating the genetic and physical chromosome maps and allows e
stimation of the relationship between physical and genetic distances t
o 1-2 Mb/cM for the distal 40% of the chromosome arms. All chromosome
arms studied showed a strongly reduced level of recombination in their
inner halves. These results are discussed in relation to the feasibil
ity of map-based cloning in barley and other cereal species.