Karyotype characterization of Turkish taxa of the genus Asperula L. - section Thlipthisa (Rubiaceae)

Abstract

Karyotype studies were performed in five taxas of Asperula viz., Asperula brevifolia, A. pseudochlorantha var. pseudochlorantha, A. pseudochlorantha var. antalyensis, A. serotina and A. purpurea subsp. apiculata from the section Thlipthisa, and their diploid (2n), and the basic (x) chromosome numbers were determined as 2n=22 and x=11, respectively. Chromosome length varied from 0.80 mm (A. serotina) to 2.40mm (A. brevifolia). Chromosomes are principally metacentric except for A serotina, which has submetacentric chromosomes. A. serotina showed the highest intrachromosomal assymetry coefficient (A1) index and A. pseudochlorantha var. antalyensis represented the highest interchromosomal asymmetry coefficient (A2). The chromosome numbers of A. brevifolia, A. serotina and A. purpurea subsp. apiculata were reported for the first time.