Houben, A.Thompson, N.Ahne, R.Leach, C.Verlin, D.Timmis, J.2006-07-052006-07-051999Plant Systematics and Evolution, 1999; 219(1):127-1350378-26971615-6110http://hdl.handle.net/2440/11500The A and B chromosomes of different karyotype variants(cytodemes A1, A2, A3 and A4) of Brachycome dichromosomatica were analysed by computer-aided chromosome image analysis and fluorescence in situ hybridisation (FISH). Ribosomal DNA and the B chromosome-specific sequence Bd49 were detected on all B chromosomes. In addition to minor size variation of the Bs, polymorphism of the rDNA and Bd49 position and copy number revealed two major types of B chromosomes. The B chromosomes of all the cytodemes were indistinguishable from each other in length, but that of A3 showed evidence of rearrangements consistent with its long-term geographic isolation. The results presented suggest a monophyletic origin of the B chromosomes of B. dichromosomatica.enJournal article0030004269001999070810.1007/BF010903040000846758000092-s2.0-003339488068275