IMPROVEMENT OF ADVENTITIOUS BUD FORMATION AND PLANTLET REGENERATION FROM IN VITRO LEAFLET EXPLANTS OF ROSES (ROSA HYBRIDA L.)

A bud regeneration system has been developed, starting from in vitro shoots of three Rosa hybrida L. cultivars: RUI 317, RUI 319 and ‘Inka’. Maximum frequency of bud regeneration (93.4% mean of three cultivars) and the highest number of buds per regenerating explant (3.7) were obtained when leaflets were cultured on induction medium of Murashige and Skoog (MS) supplemented with 6.8 μM thidiazuron (TDZ) + 0.49 μM indolebutyric acid (IBA) for 7 days in the dark, and subsequently subcultured on MS regeneration medium supplemented with 2.22 μM benzyladenine (BA) + 0.049 μM IBA exposed to low light irradiance of 15 μmol.m^-2.s^-1 photosynthetically active radiation (PAR). Bud formation capacity was also significantly affected by the genotype and the environment, such as the use of bottom cooling creating a lower relative humidity (RH) in the culture vessel.
The addition of silver nitrate to the induction medium also significantly improved the percentage of regeneration in the three genotypes tested.
Elongated shoots were excised and rooted best half strength MS medium without addition of growth regulators.

XXV International Horticultural Congress, Part 10: Application of Biotechnology and Molecular Biology and Breeding – In Vitro Culture.

R. Ibrahim, P.C. Debergh

Adventitious bud formation, bottom cooling, darkness, in vitro, low irradiance, Rosa hybrida, silver nitrate

https://doi.org/10.17660/ActaHortic.2000.520.28