ISSN:
1615-6110
Keywords:
Asteraceae
;
Brachycome
;
B chromosome
;
polymorphism
;
evolution
;
karyotyping
;
centromere
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
Notes:
Abstract The A and B chromosomes of different karyotype variants (cytodemes A1, A2, A3 and A4) ofBrachycome dichromosomatica were analysed by computer-aided chromosome image analysis and fluorescencein 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 ofB. dichromosomatica.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF01090304
Permalink
