Physical Mapping of the 18S Ribosomal RNA Gene of Peach (Prunus persica (L.) Batsch) Chromosomes by Fluorescence in situ Hybridization

The location of the 18S ribosomal RNA gene (rDNA) was studied by fluorescence in situ hybridization (FISH) on peach (Prunus persica (L.) Batsch) cv. ‘Ohatsumomo'(2n=16) chromosomes. The 18S rDNA Ioci were detected at the satellites, termini, and in the proximal regions of the respective two chromosomes. The 18S rDNA Ioci corresponded to chromomycin A3 (CMA)-positive and 4'-6-diamidino-2-phenylindole (DAPI)-negative bands of the chromosomes.