Origin and development of secondary somatic embryos in transformed embryogenic cultures of Medicago sativa
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Non-transformed and transformed embryogenic cultures of alfalfa (Medicago sativa L. cv. Zaječarska 83), long-term maintained on growth regulator-free medium, were histologically analyzed. In all examined cultures, somatic embryos at various stages of development were observed and secondary embryos were formed in the cotyledonary, hypocotylary and radicular region of the primary embryos. Detailed histological analysis of the torpedo shape somatic embryo revealed that secondary somatic embryos arose directly from single epidermal cells of hypocotylary axis after an unequal periclinal division. Bipolar proembryos were composed of one smaller cytoplasm rich cell and one larger more vacuolated cell. Further cell division pattern was similar for both non-transformed and transformed embryos. However, multicellular origin of secondary embryos in a direct process and even from callus can not be excluded.
Additional key wordsalfalfa genetic transformation histological study
green fluorescent protein
neomycin phospho-transferase II
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- Maheswaran, G., Williams, E.G.: Primary and secondary somatic embryogenesis from immature zygotic embryos of Brassica campestris.-J. Plant Physiol. 124: 455–463, 1986.Google Scholar
- Ninković, S., Miljuš-Đukić, J., Nešković, M.: Genetic engineering of herbicide-resistant alfalfa (Medicago sativa L. cv. Zaječarska 83).-In: S. Stamenković (ed.): Proc. of 2nd Balkan Symp. on Field Crops. Vol. 1. Pp. 457–460, Institute of Field and Vegetable Crops, Novi Sad 1998.Google Scholar
- Williams, E.G., Maheswaran, G.: Somatic embryogenesis: factors influencing coordinated behaviour of cells as an embryogenic group.-Ann. Bot. 57: 443–462, 1986.Google Scholar