Characterization of interphase nuclei from triploid hybrids between Pennisetum purpureum Schumach and Pennisetum glaucum (L.) R. Br.

摘要

This study evaluated the structure and the volume of interphase nuclei from root meristems of the genotypes of napier grass (Pennisetum purpureum), pearl millet (Pennisetum glaucum) and hybrids resultant of such breeding. In napier grass, nuclei were areticulate. Both pearl millet and the triploid hybrid had semi-reticulate nuclei; also, the hybrid presented a small proportion (6%) of areticulate nuclei. Pearl millet had the highest averages of nuclear dimensions, such as volume, diameter and radius, followed by the interspecific hybrid and napier grass. There was no intraspecific variation for the type of nuclear structure, which indicates this feature is important for cytotaxonomic studies involving the genus Pennisetum. Results demonstrated that chromatin organization in these nuclei was influenced by the number and size of chromosomes, affecting the nucleus volume in the analyzed taxa.