EFFECT OF GA₃ AND PACLOBUTRAZOL ON ADVENTITIOUS SHOOT REGENERATION OF TWO PELARGONIUM SP.

This study had two aims.
The first was to improve the regeneration efficiency of Pelargonium leaf discs by adventitious budding.
The second was to test the effect of gibberellic acid (GA₃) and paclobutrazol (PBZ) on callus formation and adventitious shoot regeneration in Pelargonium before using genetic transformation of this species for functional validation of genes involved in the process of GA regulation.
GA₃ and paclobutrazol (an inhibitor of GA synthesis pathway) were added (together or separately) in the shoot regeneration media of two Pelargonium species, Pelargonium × hortorum ‘Panaché sud’ (‘P.sud’) and Pelargonium × domesticum ‘Autumn haze’ (‘P.dom’). In both cases, GA₃ applied alone, completely inhibited the bud regeneration.
Moreover, the rate of callus formation decreased drastically when 5 µM of GA₃ was applied to ‘P.dom’ explants.
Similar result was obtained with ‘P.sud’ explants using 20 μM GA₃. Paclobutrazol (0.3 µM) applied at the same time as GA₃ (10 µM) could partially restore regeneration process of ‘P.dom’.
For ‘P. dom’, the use of paclobutrazol alone increased callus formation and slightly improved the rate of regeneration.
Moreover, initiated buds had a better appearance.
For ‘P. sud’, which had an abundant callusing, paclobutrazol did not improve regeneration and led to hyperhydric shoots.

VII International Symposium on In Vitro Culture and Horticultural Breeding

L. Hamama, L. Voisine, A. Naouar, R. Gala, D. Cesbron, G. Michel, F. Leplat, F. Foucher, L. Hibrand Saint Oyant, N. Dorion

Pelargonium, adventitious buds, callus formation, gibberellic acid inhibitors, dedifferentiation, differentiation

https://doi.org/10.17660/ActaHortic.2012.961.22