tailieunhanh - Ultrastructural observations in somatic embryogenesis of natural tetraploid Trifolium pratense L.
Previous reports of plant regeneration of natural tetraploid T. pratense L. ‘Elçi’ could be realized only through the apical meristem calli. In order to proceed to the production stage, other regeneration methods need to be tried. Aseptic seedlings were used for the production of somatic embryos through various 2,4-D and kinetin trials. | Turkish Journal of Botany Turk J Bot (2016) 40: 496-505 © TÜBİTAK doi: Research Article Ultrastructural observations in somatic embryogenesis of natural tetraploid Trifolium pratense L. 1, 1 2 3 Hatice ÇÖLGEÇEN *, Hatice Nurhan BÜYÜKKARTAL , Ufuk KOCA-ÇALIŞKAN Department of Biology, Faculty of Arts and Science, Bülent Ecevit University, Zonguldak, Turkey 2 Department of Biology, Faculty of Science, Ankara University, Ankara, Turkey 3 Department of Pharmacognosy, Faculty of Pharmacy, Gazi University, Ankara, Turkey Received: Accepted/Published Online: Final Version: Abstract: Previous reports of plant regeneration of natural tetraploid T. pratense L. ‘Elçi’ could be realized only through the apical meristem calli. In order to proceed to the production stage, other regeneration methods need to be tried. Aseptic seedlings were used for the production of somatic embryos through various 2,4-D and kinetin trials. Nonuniform external callus cells with translucent cytoplasm were observed in various developmental stages of somatic embryos. Beneath these cells, there were uniformly aligned, darkstained embryo cells with dense cytoplasm. Despite the similar developmental stages and cell characteristics of zygotic and somatic embryos, the walls of somatic embryo cells revealed a highly wavy pattern. The nucleus generally contained only one nucleolus, which was spherical, dark stained, and electron-dense. Electron-dense droplets were seen in vacuoles. The cytoplasm consisted of starchcontaining amyloplasts, mitochondria, plastids, ribosomes, endoplasmic reticulum, dictyosomes, lipid, and protein bodies. In some of the somatic embryos at the globular and heart stages, vacuole or electron-translucent zones were observed in the nucleolus. Additionally, a few embryo degenerations were recorded during developmental stages of the zygotic embryo. For the first time, the somatic .
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