Cytological studies of Luzula purpurea, L. multiflora, and Vicia faba, differential staining and DNA replication patterns and characterization of L. purpurea DNA

he cytological studies of Vicia fata, Luzula purpurea, and L. multiflora and the biophysical characterization of L. purpurea DNA revealed several interesting features to occur in both the organisms and DNA of organisms lacking localized centromeres. Vicia faba, an organism having chromosomes with localized centromeres, exhibited a very restricted nuclear and chromosomal distribution for C-positive, Q-positive, and DNA late-replicating regions. These regions were concentrated in the vicinity of the centromeres. Multiple C-positive and DNA late-replicating regions were scattered throughout both the nuclei and chromosomes of L. purpurea and L. multiflora. The C-positive, DNA late-replicating chromosome regions of L. purpurea were also Q-positive and composed of highly repeated DNA sequences as revealed by ^3H-RNA in situ hybridization experiments. The different techniques permitted recognition of each of the three chromosome pairs of L. purpurea even though the chromosomes are equal-sized and lack primary constrictions. [...]