N-banding analysis of rye chromosomes and the relationship between N-banded and C-banded heterochromatin

Abstract

Three of the seven chromosomes of rye (Secale cereale L.) 2R, 3R, and 6R have been identified individually by their N-banding pattern. Each of the N-banded chromosomes possesses a single band which is seen as one dot on each chromatid. Although the bands correspond with particular intercalary C-bands, they were found to be different from the remaining C-bands by sequential C- and N-banding analysis and thus reveal the heterogeneity of rye heterochromatin. It is described as C-banding and N-banding positive heterochromatin (C+N+). Similar to wheat and barley, the N-bands in rye appear to correspond to sites of (GAA)m (GAG)n sequence satellite DNA. In chromosome identification, the N-bands can be used as additional markers for the long arm of chromosome 2R (2RL), the short arm of chromosome 3R (3RS), and the long arm of chromosome 6R (6RL).Key words: heterochromatin, nonhistone proteins, banding, wheat–rye addition lines, rye.