| Popis: |
Haploid cells may be obtained either by in vitro androgenesis, i.e. the culture of anthers, pollen or microspores (Brassica) (Guha and Maheshwari 1964), or by in vitro gynogenesis, the culture of unfertilized egg cells, cells of the embryo sac (synergids, antipods, central cells) or the ovary (Yang and Zhou 1990). However, usually only a small percentage of the explants reacts by initiating direct embryogenesis. If callus is initially formed, diploid, polyploid and aneuploid cells develop as well. The sporophytes regenerated from these cells have a gametophytic chromosome constitution. |
