Visualization of nucleus substitution between Allium galanthum and shallot(A. cepa) by genomic in situ hybridization

Genomic in situ hybridization (GISH) was applied to trace the progress of n ucleus substitution in continuous backcrossing for substituting the cytopla sm of Allium galanthum Kar. et Kir. for that of shallot (A. cepa L. Aggrega tum group). Total genomic DNA of A. galanthum was used as a probe DNA along with that of shallot as a blocking DNA. In the F-1 hybrid, eight chromosom es from A. galanthum were clearly discriminated from eight chromosomes from shallot. Chromosome regions from A. galanthum noticeably decreased in the backcross progenies with frequency of backcrossing. This study demonstrates that GISH is a useful means of revealing the progress of nucleus substitut ion in the backcrossing.