Abstract
Simultaneous fluorescence in situ hybridisation
with 5S and 25S rDNA probes enables the discrimination
of a substantial number of chromosomes of the
complement of all diploid and tetraploid Brassica species
of the “U-triangle”, and provides new chromosomal
landmarks for the identification of some chromosomes
of this genus which were hitherto indistinguishable.
Twelve out of 20 chromosomes can be easily identified
in diploid Brassica campestris (AA genome), eight out
of 16 in Brassica nigra (BB genome), and six out of 18
in Brassica oleracea (CC genome). Furthermore, just
two rDNA markers permit 20 out of 36 chromosomes to
be distinguished and assigned to either the A or B genomes
of the allotetraploid Brassica juncea, and 18 out of
38 chromosomes identified and assigned to the A or C
genomes of the allotetraploid Brassica napus. The number
of chromosomes bearing rDNA sites in the tetraploids
is not in all cases simply the sum of the numbers of
sites in their diploid ancestors. This observation is discussed
in terms of the phylogeny and variability within
the genomes of the species of this group.
| Original language | English |
|---|---|
| Pages (from-to) | 486-490 |
| Number of pages | 5 |
| Journal | Theoretical and Applied Genetics |
| Volume | 103 |
| Issue number | 4 |
| DOIs | |
| Publication status | Published - Sept 2001 |