MORPHOLOGICAL AND PHYSIOLOGICAL-CHANGES DURING THIDIAZURON-INDUCED SOMATIC EMBRYOGENESIS IN GERANIUM (PELARGONIUM X HORTORUM BAILEY) HYPOCOTYL CULTURES
Mj. Hutchinson et al., MORPHOLOGICAL AND PHYSIOLOGICAL-CHANGES DURING THIDIAZURON-INDUCED SOMATIC EMBRYOGENESIS IN GERANIUM (PELARGONIUM X HORTORUM BAILEY) HYPOCOTYL CULTURES, International journal of plant sciences, 157(4), 1996, pp. 440-446
Somatic embryogenesis in geranium (Pelargonium xhortorum Bailey cv. Sc
arlet Orbit Improved) was achieved by culturing hypocotyl explants on
media supplemented with either thidiazuron (TDZ) or indol-3-yl-acetic
acid (IAA) and 6-benzylaminopurine (BAP). The physiological relationsh
ips between the morphological changes that lead to complete developmen
t of somatic embryos and the endogenous levels of plant growth regulat
ors were studied. TDZ induced similar but more pronounced and earlier
morphological changes in cultured tissues than did IAA and BAP, but af
ter 21 d in culture, both treatments promoted the formation of somatic
embryos of different developmental stages that were similar to zygoti
c embryos. TDZ induced a higher number of somatic embryos, with simila
r but greater increases in the endogenous levels of auxins and cytokin
ins, than did IAA and BAP. This may indicate that TDZ may be a more po
tent plant growth regulator in inducing physiological and morphologica
l changes than combined auxin and cytokinin, during the process of som
atic embryogenesis in geranium.