CHARACTERIZATION OF THE CHROMATIN OF SOME LILIACEOUS SPECIES AFTER DIGESTION WITH RESTRICTION ENDONUCLEASES AND SEQUENTIAL GIEMSA, FLUOROCHROME AND SILVER STAINING

A good C-banding pattern or a modified C-banding pattern is obtained after digestion with some restriction endonucleases (REs) on the fixed metaphase chromosomes of four liliaceous species. The C bands of AUium subvillosum and Muscari comosum are resistant to digestion with some REs whose recognition sequences are either GC-or AT-rich. The telomeric C-bands of A. cepa are resistant not only to some endonucleases whose recognition sequences are absent in the DNA satellite existing in these regions, but also to some endonucleases for which there exist numerous recognition sequences. However, the GC-rich C-band associated to the NOR of Scilla autumnalis is entirely digested by Hae III, and some of the faint GC-rich C-bands of the three NORs of A. subvillosum are digested by Hae III, Alu I or Rsa I. The action of endonucleases on plant chromosomes in general, and particularly on heterochromatin and NORs, together with the usefulness of these enzymes in cytogenetic analyses of plants, are discussed. © 1990 The Genetical Society of Great Britain.