Geitonogamy

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As geitonogamy (from Greek γείτων geiton , German , neighbor ' and γαμεῖν gamein , German , marry' ) or neighboring pollination , also Geitenogamie is pollination between two petals designated the same plant. From a genetic point of view, if fertilization is successful, it has the same effect as self-pollination , since there is no distribution or recombination of genetic material.

The term was first used by Anton Kerner von Marilaun in 1876 . If the neighboring pollination leads to fertilization, this is called geitonocarpy .

The assignment of geitonogamy to foreign or self-pollination is carried out differently by specialist authors. So they put the excursion flora of Rothmaler and Strasburger for self-pollination, Giesenhagen classifies them as cross-fertilization (allogamy) in the narrower sense.

Geitonogamy can be spontaneous , that is, without the involvement of external influences; like wind, water or animals, by contact with the pollen of neighboring flowers. Here, on the one hand, the elongated style of one flower can reach the pollen of the neighboring flower, and on the other hand, falling pollen can reach stigmas of other flowers of the plant. This form of geitonogamy is often found in plants with flower heads or umbels , such as the daisy family , umbelliferae and dogwood family . But it can also be caused by external influences such as wind , water or animals . B. Insects , bats, birds happen.

Faegri and Van Der Pijl describe the neighboring pollination as direct , without external influences, when it occurs through more or less permanent flower contact ; this is also known as haptogamy , as indirect , when pollen is transferred through external influences.

The neighboring pollination takes place normally in the opened flowers ( chasmogamy ). Geitonogamy and autogamy are grouped under individual or self- pollination (idiogamy, inbreeding).

The morphological adaptations that prevent self-pollination within a flower or at least reduce to such as herkogamy , dichogamy are ineffective in geitonogamy. Here only genetic self-incompatibility can prevent fertilization.

A rare, special form is the internal geitonogamy , it occurs in the Callitrichaceae , where the pollen tube germinates within the anther and grows through the axial tissue to the female flowers.

literature

Individual evidence

  1. ↑ A. Kerner: The means of protection of the flowers against uninvited guests. Vienna 1876, p. 6, online at darwin-online.org.uk, accessed on January 2, 2018.
  2. ↑ Eckehart J. Jäger (Ed.): Exkursionsflora von Deutschland. Vascular plants: baseline . Founded by Werner Rothmaler. 20th, revised and expanded edition. Spektrum Akademischer Verlag, Heidelberg 2011, ISBN 978-3-8274-1606-3 , p. 26 .
  3. ^ Joachim W. Kadereit, Christian Körner, Benedikt Kost, Uwe Sonnewald: Strasburger - Textbook of Plant Sciences . Springer, Berlin / Heidelberg 2014, ISBN 978-3-642-54435-4 , pp. 165 , doi : 10.1007 / 978-3-642-54435-4 .
  4. ↑ K. Giesenhagen: Textbook of Botany. 9th edition, Springer, 1924, ISBN 978-3-663-15325-2 (reprint), p. 77, limited preview in the Google book search.
  5. ↑ Walter Durka: Blossom and Reproduction Biology . Publication series for vegetation science, issue 38, Federal Agency for Nature Conservation, Bonn 2002, pp. 133–175, full text ( Memento of April 13, 2018 in the Internet Archive ) (PDF; 532 kB)
  6. ↑ K. Giesenhagen: p. 77.
  7. ↑ K. Faegri, L. Van Der Pijl: Principles of Pollination Ecology. Third Revised Edition, Pergamon Press, 1979, 1980 Rev. Edition, ISBN 0-08-021338-3 , p. 140, limited preview in Google Book Search.
  8. ^ R. Rieger, A. Michaelis: Genetic and cytogenetic dictionary. 2nd edition, Springer, 1958, ISBN 978-3-642-53221-4 , pp. 12, 264.
  9. ↑ Hans Kugler : Flower ecology. Fischer, 1970, p. 33.
  10. ^ C. Thomas Philbrick and Luis M. Bernardello: Taxonomic and Geographic Distribution of Internal Geitonogamy in New World Callitriche (Callitrichaceae). In: American Journal of Botany. Vol. 79, No. 8, 1992, pp. 887-890, JSTOR 2444998 .