Hordeum chilense repetitive sequences. Genome characterization using biotinylated probes.

A library of random DNA fragment clones of wild barley Hordeum chilense was screened for clones of repeated nucleotide sequences. Five clones were isolated that gave a stronger hybridization signal in colony and dot blot hybridization with total H. chilense DNA in comparison to Triticum aestivum DNA. Clones labelled with biotinylated nucleotides were used as probes to investigate the repeated sequences organization in the H. chilense genome. Tandemly arranged and interspersed sequences have been found, together with homology differences with related sequences present in T. Aestivum, which could allow the differentiation of H. chilense DNA when it is present in wheat. We show that biotin can replace the use of (32)P in preparing repeated sequence probes for Southern and DNA dot blot analyses.