In Vitro Adventitious Shoot Regeneration from Sweet Orange Using Thin Epicotyl Sections
João C. Bespalhok Filho1, Adilson K. Kobayashi2, Luiz F. P. Pereira2, Zuleide Hissano2 & Luiz G. E. Vieira2
Abstract: A system for in vitro plant regeneration from thin transversal epicotyl sections of sweet orange (Citrus sinenis L. Osbeck cvs Pera, Valencia and Folha Murcha) was developed. Thin section explants (1-2 mm) from seedlings produced adventitious shoot buds on MS medium supplemented with BA (0.5-5 μM). Optimal shoot induction was achieved on 2-5 M BA. Explants with buds were transferred to elongation media in order to improve the recovery of normal shoots. Higher number of elongated shoots was obtained on medium with 0.5 μM BA. Elongated shoots were rooted on half strength MS medium without growth regulators and transferred to soil for acclimatization. The advantages of this system for transformation are discussed.
Key words: Citrus sinensis, adventitious buds, shoot multiplication
1 Departamento de Agronomia, Universidade Estadual de Londrina (UEL), C.P. 6001, CEP 86051-990, Londrina – Paraná, Brazil
2 Instituto Agronômico do Paraná (IAPAR), C. P. 481, CEP 86001-970, Londrina – Paraná, Brazil
Balch, E.P.M. and Alejo, N. O. 1997. In vitro plant regeneration of Mexican lime and mandarim by direct organogenesis. Hortscience. 32:931-934.
Bhagwat, B.; Vieira, L. G. E. and Erickson, L. R. 1996. Stimulation of in vitro shoot proliferation from nodal explants of cassava by thidiazuron, benzyladenine and gibberelic acid. Plant Cell Tissue and Organ Culture. 46:1-7.
Gmitter Jr, F. G.; Grosser, J. W. and Moore, G. A. 1992. Citrus. p.335-369. In: Hammerschlag FA and Litz RE (Eds). Biotechnology of perennial fruit crops. Biotechnology in Agriculture n.8. CAB International, Cambridge.
Gutiérrez-E, M. A.; Luth, D. and Moore, G. A. 1997. Factors affecting Agrobacteriummediated transformation in Citrus and production of sour orange (Citrus aurantium L.) plants expressing the coat protein gene of citrus tristeza virus. Plant Cell Reports. 16:745-753.
Kaneyoshi, J.; Kobayashi, S.; Nakamura, Y.; Shigemoto, N. and Doi, Y. 1994. A simple and efficient gene transfer system of trifoliate orange (Poncirus trifoliata Raf.). Plant Cell Reports. 13: 541-545.
Moore, G. A.; Jacono, C. C.; Neidigh, J. L.; Lawrence, S. D. and Cline, K. 1992. Agrobacterium-mediated transformation of Citrus stem segments and regeneration of transgenic plants. Plant Cell Reports. 11:238-242.
Omura, M. and Hidaka, T. 1992. Shoot tip culture of Citrus. Bulletin of the Fruit Tree Research Station. 22:23-35.
Peña, L.; Cervera, M.; Juárez, J.; Navarro, A.; Pina, J. A. and Durán-Vila, N. 1995a. Agrobacterium-mediated transformation of sweet orange and regeneration of transgenic plants. Plant Cell Reports. 14:616-619.
Peña, L.; Cervera, M.; Juárez, J.; Navarro, A.; Pina, J. A. and Navarro, L. 1997. Genetic transformation of lime (Citrus aurantifolia Swing.): factors affecting transformation and regeneration. Plant Cell Reports. 16:731-737.