Analysis of Karyotypes in Leucojum

Abstract

Leucojum vernum (2n=22=2V+8i+2j+2T+8S), L. vernum var. carrathicum (2n=22=2V+8i+2j+2T+8S) and L. aestivum (2n=22=2V+8i+2j+2T+8S) have twenty-two somatic chromosomes. One pair of V-shaped chromosomes with median constrictions is distinguished from the ten remaining pairs of chromosomes with subterminal constrictions. These ten pairs may be divided into the following four classes: one pair of j-chromosomes, one pair of T-chromosomes with satellite and each four pairs of i (medium)- and S (short)-chromosomes.
Leucojum autumnale (2n=14=2V+8V'+2j+2T) has fourteen somatic chromosomes, namely five pairs of V-shaped chromosomes and each pair of j- and T-chromosomes. One pair of V-shaped chromosomes of this species is obviously homologous to those of the other Leucojum species. Other four pairs of chromosomes (V') with median constrictions which are only found in this plant may be resulted from either fusion or translocation between i- and S-chromosomes, the latter being most probable, because i.e. the V'-chromosomes have no more than only one spindle fibre attachment.