EN
The application of chromosome banding methods for plant karyosystematic studies is analyzed. The authors discuss ways of constructing C-band idiograms and interpretating the results of C-banding studies with respect to the polymorphism of heterochromatin and its histochemical differentiation. The role of quantitative changes of heterochromatin in evolution, its functional effect, and the division into dispensable and indispensable heterochromatin are presented. An overview of the recent literature on this subject is also given.