Neocentric activity in chromosome 5R of rye revealed by haploidy

Abstract

Schlegel, R. 1987. Neocentric activity in chromosome 5R of rye revealed by haploidy. - Hereditas 107: 1–6. Lund, Sweden. ISSN 0018–0661. Received October 2, 1986 In metaphase I and anaphase I of haploid ‘Petka’ rye a particular univalent chromosome with a proximal constriction can be observed in most of the pollen mother cells. A similarly shaped chromosome was also found in polyhaploid wheat-rye hybrids, triticale × wheat hybrids. and in a monosomic wheat-rye addition line derived from several rye genotypes. This chromosome behaves as a dicentric since co-orientation of the ordinary centromere and a second centromere-like structure is evident. However, the neocentric activity does not originate in the telomeres, but is confined to the proximal region of the long arm of this submeta-centric chromosome, which has been identified as chromosome 5R by the C-banding pattern (5Rq21).