INHIBITORY EFFECT OF GA(3) ON THE DEVELOPMENT OF THIDIAZURON-INDUCED SOMATIC EMBRYOGENESIS IN GERANIUM (PELARGONIUM X HORTORUM BAILEY) HYPOCOTYL CULTURES
Mj. Hutchinson et al., INHIBITORY EFFECT OF GA(3) ON THE DEVELOPMENT OF THIDIAZURON-INDUCED SOMATIC EMBRYOGENESIS IN GERANIUM (PELARGONIUM X HORTORUM BAILEY) HYPOCOTYL CULTURES, Plant cell reports, 16(6), 1997, pp. 435-438
Somatic embryogenesis in geranium (Pelargonium x hortorum Bailey cv 'S
carlet Orbit Improved') can be achieved by incubating hypocotyl explan
ts on MS medium supplemented with thidiazuron (TDZ; 10 mu M) for 3 day
s followed by subculture on medium devoid of any plant growth regulato
rs. The presence of gibberellins (GAs) during both the induction and e
xpression phases of embryogenesis was significantly detrimental to som
atic embryo formation on the hypocotyl explants. The addition of the G
A-synthesis inhibitors paclobutrazol, uniconazole or ancymidol during
the period of growth and differentiation of somatic embryos increased
the number of somatic embryos formed on each explant. However, paclobu
trazol added during the period of induction had no significant influen
ce on somatic embryo formation. Results suggest that both exogenously
supplied as well as endogenous GAs play a role, albeit a negative one,
on somatic embryogenesis of geranium.