|Authors: ||I. Forgács, B. Suller, A. Zok, A. Pedryc, R. Oláh, T. Deák, Gy.D. Bisztray, E. Szegedi|
|Keywords: ||Vitis vinifera, activated charcoal, cell suspension, maltose, 2-naphtoxyacetic acid, plant regeneration|
Somatic embryogenesis is a process in which somatic cells can be used to regenerate embryos and whole plants.
Embryogenic cell suspensions of 'Chardonnay' and 'Richter 110' grapevine cultivars were established in 8 different liquid media, cultures had been later maintained in solid media.
By the end of the sixth week, we achieved 7-fold increase of fresh weight in the case of the 'Chardonnay' cultivar, using MSM1 and CP2 liquid media.
Four different pH values of hormone-free MSM1 media were tested in our experiments (pH 5.8, pH 4.6, pH 4.3 were adjusted before autoclaving; or pH 4.3 after autoclaving). In the case of pH 5.8, we measured a 16-fold increase of fresh weight of the 'Richter110' cultivar.
Various culture densities (0.25-4 mg mL-1) were tested, and found that the one with 2 mg mL-1 density was the most efficient.
Somatic embryogenesis proved to be significantly more efficient when the medium was supplemented with 0.5 g L-1 MES buffer [2-(N-morpholino) ethanesulfonic acid]. In this case, however, the embryos regenerated developed highly elongated hypocotyls, which inhibited the germination of the embryos as well as the successful regeneration of plants.
In a half-strength MSM1 medium with a cell density of 1 mg mL-1, the cultures were composed of well synchronised globular stage embryos.
In this setup, however, further differentiation was reversibly inhibited.
This inhibition can be resolved by a second dilution of the cultures (to 1 mg mL-1 cell density). When hormone-free MSM1 medium was used after the second dilution, which was enriched with 1 g L-1 activated charcoal, synchronised and well developed cotyledonary stage embryos were differentiated in the liquid cultures by the sixth week.
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