Karyotype analysis in chaetanthera chilensis (willd.) dc. and chaetanthera ciliata ruiz et pavón (asteraceae) by double fluorescence in situ hybridization

Abstract

Karyotypes of Chaetanthera ciliata and C. chilensis from Chile were examined using the location of the 5S and 18S/25S rDNA gene sequences. Signals of 5S and 18/25S rDNA are seen in 4 and 5 of the 11 chromosome pairs in C. ciliata and C. chilensis, respectively. The reported karyotypes are symmetric with small chromosomes and a great similarity among them. Chromosome asymmetry indexes (AsI % and A1) were similar for both species. This report is the first on chromosome number and karyotype analysis of Chaetanthera ciliata and C. chilensis. One of the remarkable differences between the karyotypes of C. ciliata and C. chilensis is that C. ciliata has only metacentric chromosomes, whereas C. chilensis has a submetacentric chromosome pair. Using the FISH technique, notable differences can be observed with respect to the position and number of rDNA sequences depending on the chromosome. © 2005 Taylor and Francis Group, LLC.