Karyotype analysis of Ethiopian endemic Kniphofia species

Abstract

Image analysis was used to study the karyotype of six Ethiopian Kniphofia species: K. foliosa, K. hildebrandtii, K. insignis, K. isoetifolia, K. schimperi and K. pumila. The first five are endemic to Ethiopia. All have somatic chromosome number of 2n = 12, and follow the same karyotype formula: 1m + 3sm + 2st. There was significant variation among the species as to size and arm length of the chromosomes. However, the arm ratio (r) was not significantly different, indicating the centromeric position is constant among the species. The results indicated that the species (with the possible exception of K. foliosa) were closely related. The species differ morphologically, particularly, in flower size and shape, which obviously must be closely correlated to pollinator shape, size and activity. The evolutionary relationships among the taxa should further be studied using DNA sequences data from chloroplast and nuclear markers to elucidate the phylogenetic relationship of the Kniphofia  species in Ethiopia.

Keywords/phrases: Endemic, Ethiopia, Karyotype Kniphofia, Speciation

Ethiop. J. Biol. Sci., 7(1): 35-43, 2008