EN
Morphology of conventionally stained and C-banded chromosomes of three plant species (Allium vineale L., Secale segetale Zhuk. and S. afganicum Vav.) was investigated. C-banding was found to shorten chromosomes more than other staining methods used. Although the arm ratio of chromosomes but whole genome composition was generally unchanged. Particular chromosomes in some metaphase plates showed, however, distinct morphological modifications. Their arm ratio was enormously altered due to very uneven shortening of both chromosome arms. The mechanisms of these changes and their significance in karyotype investigation are discussed.