Karyotype analysis in meiosis: Giemsa banding in the genus Secale L.

Terminal bands of meiotic chromosomes stained by the Giemsa technique are permanent genetic structures of the nucleus during PMC differentiation in 8 samples of wild, primitive, and cultivated species of rye. The characteristic meiotic banding pattern is probably identical with the heterochromatic regions of mitotic chromosomes of root meristem cells (RMC) which have so far been studied. Karyotype analysis can be significantly improved by quantitative studies of the number and size of the bands combined with certain well-known chromosome characters in diplotene and diakinesis. The chromosomes involved in multivalents of some natural and synthetic species hybrids are identified for the first time. The results are discussed both in relation to the problems of chromosome evolution and their significance for marker techniques in cytogenetics.