2012 Volume 7 Issue 2 Pages 47-52
The ploidy level and the phylogenic position of Lachenalia congesta W. F. Barker (Asparagaceae) were analyzed by karyomorphological, molecular cytogenetical and molecular phylogenetical studies. The chromosome number of L. congesta was 2n=28, and these chromosomes showed bi-modal karyotype with four large sized chromosomes and 24 small sized chromosomes. The ploidy level of this species was diploid, because each two chromosomes made 14 pairs on the karyotype analysis by acetoorcein staining, DAPI staining and FISH methods. In addition two signals of 18S rDNA sites were detected by the FISH method supported this assumption. All 28 chromosomes of this species did not show any clear DAPI-positive bands and four signals of 5S rDNA sites were detected near the centromeres of small sized chromosomes. These characters were quite different from the characters observed by karyomorphological and molecular cytogenetical studies on common Lachenalia species with basic chromosome number of x=7 or 8. The data from molecular phylogenetic analysis of internal transcribed spacer (ITS) region supported this hypothesis.