Abstract
The structure and behaviour of free female, male and proembryonal nuclei ofEncephalartos villosus Lem. were studied during a light-microscopical investigation of serially sectioned archegonia in successfully pollinated ovules. Before spermatozoids were released from the pollen tubes into the archegonial chamber, the ventral canal nucleus had disintegrated in the neck region of the egg cell among minute, amoeboid bodies with PAS-positive granules. In archegonia containing multiple spermatozoids, the egg nucleus was unobtrusive and syngamy followed by proembryo formation regularly resulted. The egg cell usually reacted violently in archegonia penetrated by a single spermatozoid. These reactions were regarded as rejection phenomena and considered as indicators that the egg cell can differentiate between compatible and incompatible male gametes.
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References
Bell PR (1994) Apomictic features revealed in a conifer. Int J Plant Sci 155:621–622
Brough P, Taylor MH (1940) An investigation of the life cycle ofMacrozamia spiralis Miq. Proc Linn Soc NSW 65:494–524
Bryan GS, Evans RI (1956) Chromatin behaviour in the development and maturation of the egg nucleus ofZamia umbrosa. Am J Bot 43:640–646
Bryan GS, Evans RI (1957) Types of development from the central nucleus ofZamia umbrosa. Am J Bot 44:404–415
Chamberlain CJ (1906) The ovule and female gametophyte ofDioon. Bot Gaz 42:321–358
Chamberlain CJ (1912) Morphology ofCeratozamia. Bot Gaz 53: 1–19
De Sloover JL (1961) Études sur les Cycadales. I. Méiose et mégasporogenèse chezEncephalartos poggei Asch. Cellule 62:103–116
De Sloover JL (1964) Études sur les Cycadales III. Nucelle, gamétophyte femelle et embryon chezEncephalartos poggei Asch. Cellule 64:147–200
Dilcher DL (1979) Early angiosperm reproduction: an introductory report. Rev Palaeobot Palynol 27:291–238
Fisher DB (1968) Protein staining for ribboned epon sections for light microscopy. Histochemie 16:92–96
Jacobsen JV, Knox RB, Pyliotis NA (1971) The structure and composition of aleurone grains in the barley aleurone layer. Planta 101:189–209
Jensen WA (1962) Botanical histochemistry. Freeman, San Francisco, pp 73, 198-199, 246-253
Johnson LAS, Wilson KL (1990) General traits of the Cycadales. In: Kramer KU, Green PS (eds) Pteridophytes and gymnosperms. (the families and genera of vascular plants, vol 1) Springer, Berlin Heidelberg New York, pp 363–368
Kirk ITO (1978) Proplastids, etioplasts, amyloplasts, chromoplasts and other plastids. In: Kirk JTO, Tilney-Bassett RAE (eds) The plastids: their chemistry, structure, growth and inheritance, revised edn. North Holland Biomedical Press, Amsterdam, pp 219–237
Ling-Lee M, Chilvers GA, Ashford AE (1977) A histochemical study of phenolic materials in mycorrhizal and uninfected roots ofEucalyptus fastigata Dean and Maiden. New Phytol 78:313–332
Mamay SH (1976) Palaeozoic origin of the cycads. US Geological Survey professional paper 934:1–48
Norstog K (1977) The spermatozoid ofZamia chigua Seem. Bot Gaz 138:409–412
O'Brien TP, Feder N, McCully ME (1964) Polychromatic staining of plant cell walls by toluidine blue O. Protoplasma 59:368–3731
O'Brien TP, McCully ME (1981) The study of plant structure: principles and selected methods. Termacarphi, Melbourne, pp 4.19–4.22, 6.81-6.88
Osborne R (1995) An overview of Cycad conservation in South Africa. In: Donaldson IS (ed) Cycad conservation in South Africa: issues, priorities and actions. Cycad Society of South Africa, Stellenbosch, pp 1–7
Pettitt JM (1977) Detection in primitive gymnosperms of proteins and glycoproteins of possible significance in reproduction. Nature:530–532
Pettitt JM (1982) Ultrastructural and immunocytochemical demonstration of gametophytic proteins in the pollen tube wall of the primitive gymnospermCycas. J Cell Sci 57:189–213
Raff MC (1992) Social controls on cell survival and cell death. Nature 356:397–399
Sedgwick PJ (1924) Life-history ofEncephalartos. Bot Gaz 77:300–310
Steyn EMA (1993) Spermatozoids ofEncephalartos villosus. Encephalartos 36:18–20
Steyn EMA, Strydom DJF (1993) The nucellus: its position and function in the ovule ofEncephalartos. Encephalartos 35:14–18
Willson MF, Burley N (1983) Mate choice in plants: tactics, mechanisms, and consequences. Princeton University Press, Princeton, pp 47–127
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Steyn, E.M.A., Strydom, W.F. & Botha, A. Fertilization and rejection of spermatozoids by egg cells in artificially pollinated ovules ofEncephalartos (Zamiaceae). Sexual Plant Reprod 9, 175–185 (1996). https://doi.org/10.1007/BF02221398
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DOI: https://doi.org/10.1007/BF02221398