caa a22 4500 463236408 CHVBK 20180405153258.0 cr unu---uuuuu 170326e20070501xx s 000 0 eng 10.1007/s11240-007-9221-8 doi (NATIONALLICENCE)springer-10.1007/s11240-007-9221-8 Light cytokinin interactions in shoot formation in epicotyl cuttings of Troyer citrange cultured invitro [Elektronische Daten] [R. Molina, S. Castelló, A. García-Luis, J. Guardiola] Ilumination did not affect the pathway of shoot regeneration at the cut edges of epicotyl explants of Troyer citrange (Moreira-Dias etal. 2000, 2001), but signigficantly affected the number of developed shoots and the response to exogenous cytokinins. Shoot regeneration at the apical end occurred through a direct organogenic pathway without callus formation. For explants incubated in the light, this regeneration did not require cytokinin addendum, but the number of shoots formed was significantly increased by benzyl adenine, but not by zeatin or kinetin. Incubation in the dark almost suppressed shoot formation at the apical end. The addition of benzyl adenine or kinetin, but not of zeatin, restored shoot formation in the dark to the value obtained in the light. At the basal end of the explants shoot regeneration occurred through an indirect organogenic pathway after the formation of a primary callus. In explants incubated in the light, callus formation and shoot growth was supported by a low (0.5-1mgl−1) benzyl adenine concentration and by zeatin. Kinetin did not support callus growth. Shoot formation was higher in the presence of benzyl adenine (0.5-1mgl−1) than of zeatin, but was inhibited by a high (5mgl−1) benzyl adenine concentration. Incubation in the dark increased callus growth and shoot formation at the basal cut as compared to explants incubated in the light. The three cytokinins tested supported callus growth and shoot formation in the dark, zeatin being the most effective and kinetin the least. In terms of number of shoots developed, the optimum cytokinin addendum depended on the pathway of organogenesis and the conditions of incubation. The maximum number of shoots developed at the apical end was obtained when the incubation was performed in the light in the presence of benzyl adenine. At the basal end, the optimal conditions were incubation in the dark in the presence of zeatin. It was not always possible to define an optimal cytokinin concentration as the curve concentration/response varied from experiment to experiment, which seemed unrelated to the endogenous cytokinin concentration in the explants. Springer Science+Business Media B.V., 2007 Citrus sinensis × Poncirus trifoliata nationallicence Cytokinins nationallicence Benzyl adenine nationallicence Kinetin nationallicence Illumination nationallicence Organogenesis nationallicence Troyer citrange nationallicence Zeatin nationallicence BA : 6-Benzylaminopurine nationallicence K : Kinetin nationallicence Z : Zeatin nationallicence Molina R. Departamento de Biología Vegetal, Universidad Politécnica de Valencia, 46071, Valencia, Spain aut Castelló S. Departamento de Biología Vegetal, Universidad Politécnica de Valencia, 46071, Valencia, Spain aut García-Luis A. Departamento de Biología Vegetal, Universidad Politécnica de Valencia, 46071, Valencia, Spain aut Guardiola J. Departamento de Biología Vegetal, Universidad Politécnica de Valencia, 46071, Valencia, Spain aut Plant Cell, Tissue and Organ Culture Kluwer Academic Publishers 89/2-3(2007-05-01), 131-140 0167-6857 89:2-3<131 2007 89 11240 https://doi.org/10.1007/s11240-007-9221-8 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s11240-007-9221-8 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Molina R. Departamento de Biología Vegetal, Universidad Politécnica de Valencia, 46071, Valencia, Spain aut NATIONALLICENCE 700 1- Castelló S. Departamento de Biología Vegetal, Universidad Politécnica de Valencia, 46071, Valencia, Spain aut NATIONALLICENCE 700 1- García-Luis A. Departamento de Biología Vegetal, Universidad Politécnica de Valencia, 46071, Valencia, Spain aut NATIONALLICENCE 700 1- Guardiola J. Departamento de Biología Vegetal, Universidad Politécnica de Valencia, 46071, Valencia, Spain aut NATIONALLICENCE 773 0- Plant Cell, Tissue and Organ Culture Kluwer Academic Publishers 89/2-3(2007-05-01), 131-140 0167-6857 89:2-3<131 2007 89 11240 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer