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Polyembryonia is a form of asexual reproduction . In the case of seed plants , this describes the formation of several embryos in one ovule or in one seed . This loose definition encompasses several different ways in which the embryos form. In animals, this describes the formation of identical multiples.


In the actual polyembryony, the embryos all arise from a single zygote . This is common in gymnosperms . In most cases, however, only one embryo develops to maturity.

There is also sporophytic polyembryony, in which the embryos develop from the tissue of the maternal sporophyte, from the nucellus or the integument , or from the zygote, the proembryo or suspensor cells. Gametophytic polyembryos arise from different cells of the embryo sac than the egg cell. These are the synergids or the antipodal cells.

In Pinus and some Podocarpaceae , the suspensor splits into four parts, giving rise to four embryos. In Gnetum there are several egg cells and thus zygotes per ovule; additional embryos are created from each zygote through branching of the primary and secondary suspensors. Usually, however, only one mature embryo develops per seed. In the case of ephedra , the zygote divides three times, and the eight cells that are formed usually produce three to five embryos.

In angiosperms , polyembryonia occurs in a number of families . In the genus Citrus it occurs regularly, in some species in almost every ovule. Adventitious embryos that arise from the nucellus, the nucellar embryonia , are more common than those from the integument. It occurs in many dicots and in some monocots ( Liliaceae , Amaryllidaceae , Orchidaceae , Araceae , Poaceae ). Integument embryos occur predominantly with dicots, among the monocots only with Liliaceae and Amaryllidaceae. Well-known examples of polyembryonia are, besides Citrus Mangifera , Opuntia , Nicotiana , Funkia , Lilium , Erythronium , Allium and Poa .

The formation of one embryo from several egg cells or embryo sacs in an ovule is called pseudopolyembryony. This is known from Trifolium , Rosa and Saxifraga .


The zygote disintegrates into several daughter germs at a very early single or multicellular stage. These are genetically identical.

Polyembryonia occurs in some invertebrates such as B. moss animals , earthworms , some species of parasitic wasps , armadillos and occasionally other mammals as well as humans. This creates identical multiples.

supporting documents

  • Arthur J. Eames: Morphology of the Angiosperms . McGraw-Hill, New York 1961, OCLC 327546 , pp. 345-347. (Botany)
  • Gertrud Scherf: Dictionary of Biology. dtv, 1997, ISBN 3-423-32500-3 .
  • W. Westheide, R. Rieger: Special Zoology. Part 1: Protozoa and invertebrates. Gustav Fischer Verlag, Stuttgart / Jena / New York 1996, ISBN 3-437-20515-3 .

Individual evidence

  1. ^ Gerhard Wagenitz : Dictionary of Botany. The terms in their historical context. 2nd, expanded edition. Spektrum Akademischer Verlag, Heidelberg / Berlin 2003, ISBN 3-8274-1398-2 , p. 257.
  2. ^ KR Sporne: The Morphology of Gymnosperms. Hutchinson University Library, London 1965, OCLC 307390 , pp. 138, 152, 179, 187.

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