Growth responses of in vitro-derived nodal sections of Kalanchoe blossfeldiana Poellnitz as influenced by benzylaminopurine, thidiazuron and paclobutrazol

In vitro-derived nodal explants of Kalanchoe blossfeldiana Poelin. genotype 'White' were successfully regenerated in Murashige and Skoog's (1962) medium supplemented with BAP or TDZ alone or in combination with PAC. The nodal explants developed new shoots from the 7th to the 11th days after inoculation varying levels of TDZ medium, with or without PAC. The highest shoot proliferation was attained with 10 mu M TDZ, producing 25 shoots by the 12th week of incubation. Addition of PAC significantly reduced the overall growth of the cultures: number of leaves, leaf width, stem diameter, internode length, shoot length and shoot proliferation. Inhibition of shoot proliferation by PAC was significantly observed when applied together with TDZ. Extensive shoot branching was observed on the 12th week after inoculation. Ethylene concentrations at the headspace of the culture vessels were low in all treatments, (0.015-0.039 ppm), suggesting no influence of ethylene on the response of the K. blossfeldiana nodal cultures.