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Ultrastructural modifications of plastids and starch metabolism during the microsporogenesis of Ophrys lutea (Orchidaceae)
- Feijo, J.A., Pais, M.S.S.
- Annals of botany 1988 v.61 no.2 pp. 215-219
- Ophrys lutea, plastids, starch
- Ultrastructure of plastids has been studied throughout microsporogenesis of Ophrys lutea Cav. (Orchidaceae). A typical dedifferentiation/redifferentiation cycle of plastids was observed. At prophase I, plastids of pre-meiocytes gradually lost starch and separated the meiocytes through cytomictic channels. At meiosis, plastids dedifferentiated to protoplasts and redifferentiated in young microspores. During pollen grain formation and maturation a cycle of starch accumulation/degradation occurred; the mature pollen grain is starchless. Results are discussed in terms of genetic inheritance following haploid nuclear state and in terms of carbohydrate metabolism.