ABSTRACT
The aim of this study was to analyse the karyotype by using root tips of three species of the Aloe genus namely Aloe sabaea, A. shadensis, and A. castellorum and to differentiate between them from the view point of chromosomes taxonomy. In addition, the study aimed at determining the DNA concentration for the three species. Chromosome number of these three species was 2n = 14. It consisted of four pairs of large subtelocentric chromosomes and three pairs of relatively small submetacentric chromosomes. The presence of a secondary constriction was clearly visible positioned in the distal end of the long arm of the second chromosome pair in A. shadensis, and on the long arm of the first chromosome pair in A. castellorum, but not observed in A. sabaea. Chromosomes length, arm ratio, the relative length, and the total chromatine length were calculated. The length of the chromosome complement already indicated that the species of Aloes possess a large genome. The DNA concentrations were determined through spectrophotometer measurements, they were 3.46, 5.58, and 4.41 micro g/ml in A. sabaea, A. shadensis, and A. castellorum. respectively. These significant variations in the DNA concentrations along with the observed differences in the Karyotypes would strongly support the species status of each one of them and support their current recognized taxonomic status