| Popis: |
Plant regeneration from in vitro cultures originating from different explants (anthers, young inflorescences, immature embryos, leaf bases) has been achieved from all the major cereal crops. Regeneration is accomplished via either shoot-root morphogenesis or somatic embryogenesis. Special efforts have been made to establish embryogenic cultures, as somatic embryos are superior in producing single cell derived and true type regenerants. Embryogenic cultures have been induced from Zea mays, Oryza sativa, Hordeum vulgare, Triticum aestivum, Secale cereale and Triticale. The efficiency of culture initiation, long term maintenance of totipotent cultures, and plant regeneration is influenced by the genotype used, the media composition and physical culture conditions. Not all of the tissue culture derived plants exhibit a normal phenotype and those are classified as somaclonal variants. The regenerated plants and their progeny are analyzed genetically and at the molecular level. These studies include investigations as to whether gene expression in tissue culture derived plants is altered by the degree of methylation, or can be related to deletions, inversions or other rearrangements in known gene sequences. |
