QUANTITATIVE KARYOTYPING OF 3 DIPLOID BRASSICA SPECIES BY IMAGING METHODS AND LOCALIZATION OF 45S RDNA LOCI ON THE IDENTIFIED CHROMOSOMES

Chromosomes of the three diploid Brassica species, B. rapa (AA), B. ni gra (BE) and B. oleracea (CC), were identified based on their morpholo gical characteristics, especially on the condensation pattern appearin g at the somatic pro-metaphase stage. The morphological features of th e pro-metaphase chromosomes of the three Brassica spp. were quantified by imaging methods using chromosome image analyzing system II (CHIAS 2). As a result, quantitative chromosome maps or idiograms of the thre e diploid Brassica spp. were developed. The fluorescence in situ hybri dization (FISH) method revealed the location of 45s rDNA (the 26s-5.8s -18s ribosomal RNA gene cluster) on the chromosomes involved. The numb er of 45s rDNA loci in the B. rapa, B. nigra and B. oleracea are five, three and two, respectively. The loci detected were systematically ma pped on the idiograms of the three Brassica spp.