Abstract
In vitro regeneration and histological analysis of somatic embryogenesis derived from in vitro leaves were assessed in Phlox paniculata L. The explants were incubated on Murashige and Skoog medium containing 2.26–4.52 μM 2,4-dichlorophenoxyacetic acid (2,4-D) with or without 0.89 μM benzyladenine supplemented with 3% or 9% sucrose and vitamins. The intact leaf blades were cultured in the dark at temperature 22 ± 2°C. Two Phlox cultivars showed significantly higher regeneration capacity in the in vitro conditions when the cultivation media have been supplemented with 2,4-D at concentrations of 4.52 μM and 3% sucrose. The effect of 2,4-D on somatic embryo induction has been enhanced in presence of cytokinin benzyladenine. In cultivars, the embryogenic structures have been created on calluses derived from leaf sections within 6–9 weeks in culture. Meristematic zones with forming embryogenic structures were mostly localized adjacent to de novo forming tracheal elements in calluses in our experiments. In the absence of tracheal elements, the embryogenic structures have been surrounded by several layers of isodiametric cells. The embryo proper and the suspensor part could be clearly distinguished on the embryogenic structures. The embryogenic potential of cultures has been very high, so that even secondary and tertiary somatic embryos were formed. Within 6–9 weeks in culture, well differentiated embryogenic structures up to torpedo stages were developed. Cultivar ‘Fuji’ exhibited slightly higher embryogenic response in culture than cultivar ‘Starfire’. The cultures maintained their embryogenic potential for about 18 months. Embryogenic structures have been able to convert to complete plants within 3 months.
Acknowledgements
This work was financially supported by the Ministry of the Environment of the Czech Republic (project MZP0002707 301), and has been elaborated within Czech-Slovak cooperation.
References
Chen S., Liang M., Li Q. & Xu M. 2008. Study of rapid propagation of Phlox paniculata. Plant Cell Tiss. Org. 95: 245–250.10.1007/s11240-008-9431-8Search in Google Scholar
Declerck V. & Korban S.S. 1995. Shoot regeneration from leaf tissues of Phlox paniculata L. J. Plant Physiol. 147: 441–446.10.1016/S0176-1617(11)82180-2Search in Google Scholar
Dedičová B., Obert B., Hricová A., Šamaj J., Bobák M. & Pret’ová A. 2000. Shoot and embryo-like structures regenerated from from cultured flax (Linum usitatissimum L.) hypocotyl segments. J. Plant Physiol. 157: 327–334.10.1016/S0176-1617(00)80055-3Search in Google Scholar
Fraga M., Alonso M. & Borja M. 2004. Shoot regeneration rates of perennial phlox are dependent on cultivar and explant type. Hort. Sci. 39: 1373–1377.10.21273/HORTSCI.39.6.1373Search in Google Scholar
Jain A., Rout G.R. & Raina S.N. 2002. Somatic embryogenesis and plant regeneration from callus cultures of Phlox paniculata Linn. Sci. Hort. 94: 137–143.10.1016/S0304-4238(01)00369-7Search in Google Scholar
Mackay W.A., Sankhla D. & Sankhla N. 1999. Micropropagation of superior selections of perennial phlox. In Vitro Cell. Dev. Biol. – Plant 35: 49–53.Search in Google Scholar
Matiska P. & Vejsadová H. 2010. Polyploidy induction in Phlox paniculata L. under in vitro conditions. Acta Univ. Agric. Silvic. Mendelianae Brun. 58: 101–106.10.11118/actaun201058010101Search in Google Scholar
Matiska P., Vejsadova H. & Pretova A. 2006. Induction of morphogenesis in Phlox paniculata L, p. 58. In: XXII EUCARPIA Symposium (Section Ornamentals) “Breeding for Beauty”, Book of Abstracts, 11-15 September 2006, Sanremo, Italy.Search in Google Scholar
Murashige T. & Skoog F. 1962. A revised medium for rapid growth and bioassays with tobacco tissue cultures. Physiol. Plant. 15: 473–497.10.1111/j.1399-3054.1962.tb08052.xSearch in Google Scholar
Nau J. 1996. Ball Perennial Manual: Propagation and Production. Ball Publishing, Batavia, IL, USA, 487 pp.Search in Google Scholar
Olensen M.N. & Fonnesbech M. 1975. Phlox plants from shoot tips. Acta Hort. 54: 95–99.10.17660/ActaHortic.1975.54.12Search in Google Scholar
Pret’ová A. & Williams E.G. 1986a. Direct somatic embryogenesis from immature zygotic embryos of flax Linum usitatissimum L. J. Plant Physiol. 126: 155–161.10.1016/S0176-1617(86)80016-5Search in Google Scholar
Pret’ov’ A. & Williams E.G. 1986b. Zygotic embryo cloning in oil seed rape (Brassica napus L.). Plant Sci. 47: 195–198.10.1016/0168-9452(86)90178-0Search in Google Scholar
Raghavan V. 2004. Role of 2,4-dichlorophenoxyacetic acid (2,4-D) in somatic embryogenesis on cultured zygotic embryos of Arabidopsis: cell expansion, cell cycling, and morphogenesis during continuous exposure of embryos to 2,4-D. Am. J. Bot. 91: 1743–1756.10.3732/ajb.91.11.1743Search in Google Scholar PubMed
Šamaj J., Baluška F., Bobak M. & Volkmann D. 1999. Extracellular matrix surface network of embryogenic units of friable maize callus contains arabinogalactan-proteins recognized by monoclonal antibody JIM 4. Plant Cell Rep. 18: 369–374.10.1007/s002990050588Search in Google Scholar
Schnabelrauch L.S. & Sink K.C. 1979. In vitro propagation of Phlox subulata and Phlox paniculata. Hort. Sci. 14: 607–608.Search in Google Scholar
Vejsadová H. & Pret’ov’. 2000. Cytological and histological study of morphogenesis in Rhododendron L. Adv. Hort. Sci. 14: 87–91.Search in Google Scholar
Vejsadová H. & Pret’ov’. 2003. Somatic embryogenesis in Rhododendron catawbiense ‘Grandiflorum’. Acta Hort. 616: 467–470.10.17660/ActaHortic.2003.616.73Search in Google Scholar
Wherry E.T. 1955. The genus Phlox. Morris Arboretum Monographs III, Philadelphia, PA, USA.Search in Google Scholar
- Abbreviations
- 2,4-D
2,4-dichlorophenoxyacetic acid
- BA
benzyladenine.
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