LOCALIZATION OF INTRODUCED GENES ON THE CHROMOSOMES OF TRANSGENIC BARLEY, WHEAT AND TRITICALE BY FLUORESCENCE IN-SITU HYBRIDIZATION

Using fluorescence in situ hybridization (FISH) we localized introduce d genes on metaphase chromosomes of barley, wheat, and triticale trans formed by microprojectile bombardment of microspores and scutellar tis sue with the pDB1 plasmid containing the uidA and bar genes. Thirteen integration sites were detected in the nine lines analysed. Southern a nalysis showed that three or more copies of the plasmid were present i n the lines. In a triticale line containing four copies three differen t integration sites were identified, indicating that the method descri bed is sensitive enough for the detection of single-copy integrations. There was a slight tendency towards the localization of transgenes in distal chromosome regions. Using the GAA-satellite sequence for chrom osome banding, the chromosomes containing the inserted genes were iden tified in most cases. Two barley lines derived from the same transform ant showed a totally different integration pattern. Southern analysis confirmed that the inserted genes were segregating independently, resu lting in different integration patterns among the progeny lines. The a pplication of the FISH technique for the analysis of transgenic plants is discussed.