Genome Diversity of Triticale (x Triticosecale Witt.) Using the Chromosome Heterochromatin Marker

Many forms of triticale are characterized by a varying number of rye chromosomes identified on the basis of the presence of telomeric heterochromatin. In spring forms, high yielding and of good quality, the number of rye chromosome pairs most often was 6-7. Substitutions of D chromosome were confirmed in place of defined rye chromosomes; the most frequent was 2R chromosome. Numerous modifications of rye chromosomes were observed with regard to the presence of telomeric heterochromatin as well as structural mutations. Winter triticale was characterized by a more stable karyotype as in most of the varieties and lines studied a complete rye genome with clear bands of telomeric heterochromatin was present. Thus it may be concluded that depending on the type of triticale, spring or winter, there exists a genotype factor controlling the biological activity of chromatin, which is reflected in the presence or absence of heterochromatin blocks or whole chromosomes of rye. Observation of the course of meiosis in triticale proved that rye chromosomes with clear heterochromatin bands most often participate in disturbances, especially in primary forms. However, in high-yielding forms meiosis is regular and univalent rye chromosomes were observed only in sporadic cells.