Résumé:
Six varieties of wheat resulting from mature embryos were cultivated on MS
medium added at 2 different concentrations of 2.4-D in order to induce the
callogenesis. The best results are retained for the culture of immature embryos.
Differing parameters were considered: reaction of the scutellum, time of callus
induction, area of calli, rate of callogenesis. A selective pressure (PEG) was applied
to these calli during 30 days. Al calli were transferred on to regenerated medium. 4
types of calli were obtained from mature and immature embryos. The growth
regulators are necessary for the development of roots (AIA+BAP) but inhibiting for
the embryogénie calli. The immature embryos regenerate the most plants, however
the mature embryos cultivated on the 2.4-D+AgN03 have the best performances of
callogenesis. The regenerated seedlings present morphological variations relating to
the size and the orientation of the foliage, and the vegetative cycle. These
morphological variations appear since the stage callus through diversity of the growth
of the calli, the morphological appearance, as well as the various answers of the
cellular lines subjected to the PEG. We find these variations in the same genotype
resulting from the same type of embryo. The durum wheat was shown more tolerant
than the bread wheat. As for regeneration, the immature embryos seem made up the
ideals expiants for regeneration like for obtaining tolerant plants.
