Lewis Knudson

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Lewis Knudson (born October 15, 1884 in Milwaukee , † August 31, 1958 in Ithaca (City, New York) ) was an American botanist . He taught plant physiology at Cornell University and was best known for his work on orchids .

Life

Lewis Knudson was the son of a Norwegian sea captain who emigrated to the United States. He graduated from the University of Missouri with a bachelor's degree in agricultural science . He moved to Cornell University for his doctorate, where he then became an assistant professor in plant physiology . In 1921 he was appointed professor. After emerging from 1952 he stayed in Ithaca, where he died of a heart attack in 1958 .

Orchids

In 1899, Noël Bernard discovered that orchid seeds need a symbiosis with molds to germinate . Knudson has now discovered that it is not the molds themselves that are essential, but that the molds make simple sugar molecules accessible. Therefore, he prepared a nutrient solution that, in addition to inorganic salts, also contains cane sugar . With this, millions of orchid seedlings can be obtained on aseptic agar .

The first nutrient solution was named Knudson's B and was based on a medium by Wilhelm Pfeffer . Knudson's C, which is widely used today, is a further development of this and was published in 1946.

If orchid seeds can germinate under aseptic conditions on a pure nutrient medium, then this raises the question of how specific the orchid-fungus relationship ( mycorrhiza ) is in the wild. Knudson's position is that there is no such specificity and that an orchid can enter into a symbiosis with different fungi . He believes the fungus is a parasite . There is no consensus in science on this issue.

Works

  • L. Knudson: Nonsymbiotic Germination of Orchid Seeds . In: Botanical Gazette . tape 73 , no. 1 , 1922, pp. 1-25 .

literature

  • J. Arditti: Plenary Presentation: History of orchid propagation . In: AsPac J. Mol. Biol. Biotechnol. tape 18 , no. 1 , 2010, p. 171-174 .
  • Teoh Eng Soon: Orchids of Asia . 3. Edition. Times Editions - Marshall Cavendish, Singapore 2005, ISBN 981-261-015-4 , pp. 33-39 .

Individual evidence

  1. ↑ TW Yam, J. Arditti: History of orchid propagation: a mirror of the history of biotechnology . In: Plant Biotechnology Reports . tape 3 , 2009, p. 1-56 , doi : 10.1007 / s11816-008-0066-3 .
  2. ^ Joseph Arditti: Micropropagation of Orchids, Volume 1 . 2nd Edition. Blackwell Publishing Ltd., 2008, ISBN 978-1-4443-0040-6 , pp. 18-21 .
  3. ^ Robert L. Dressler: The orchids . Ulmer, Stuttgart 1987, ISBN 3-8001-6331-4 , p. 88-91 .
personal data
SURNAME Knudson, Lewis
BRIEF DESCRIPTION American botanist
DATE OF BIRTH October 15, 1884
PLACE OF BIRTH Milwaukee
DATE OF DEATH August 31, 1958
Place of death Ithaca (City, New York)