Karyotype Analysis in the Genus Asiasarum F. Maek. (Aristolochiaceae)

Abstract

The somatic chromosome numbers and karyotypes of five species of Asiasarum (Aristolochiaceae), representing seven distinct taxa, were studied. The seven taxa had the same somatic chromosome number, 2n=26. With one exception, they had the same chromosome complements, 10m+3st. The exception was A. maculatum with 11m+2st. These seven taxa commonly had three pairs of small chromosome, among which one pair of small chromosomes (No. 11) with a satellite, and one pair of small chromosome (No. 12) with a secondary constriction at the distal portion of the short arms. The somatic chromosome number and karyotype of A. patens, and A. sieboldii var. versicolor and karyotype of A. heterotropoides var. mandshuricum are reported for the first time. The similarity in chromosome number and karyotype suggests that Asiasarum is a well-defined phyletic group belonging to Asarum sensu lato.