Triangle of U


Triangle of U

The Triangle of U is a theory about the evolution and relationships between members of the plant genus "Brassica". It says that the genomes of three ancestral species of "Brassica" combined to create three of the common vegetables and oilseed crop species that we know today. The theory has since been confirmed by studies of DNA and proteins.

The theory was first published in 1935 by Woo Jang-choon, a Korean botanist who was working in Japan (where his name was transliterated as "Nagaharu U" [http://junior.sciencetimes.co.kr/data/article/7000/0000006890.jsp (in Korean)] ). Woo made synthetic hybrids between the diploid and tetraploid species and examined how the chromosomes paired in the resulting triploids. His work was influenced by work by Kihara on the origin of bread or hexaploid wheat and its relationship to its diploid ancestors.Fact|date=July 2008

The triangle shows how three of the "Brassica" species were derived from three ancestral genomes, denoted by the letters AA, BB, or CC. Alone, each of these diploid genomes produces a common "Brassica" species. The letter "n" denotes the number of chromosomes in each genome, and is the number found in the pollen or ovule. For example "Brassica rapa" has an A - n=10 (alternatively AA - 2n=20) designation. That means each somatic cell of the plant contains two complete genome copies (diploid) and each genome has ten chromosomes. Thus each cell will contain 20 chromosomes; since this is the diploid number it is written as 2n = 2x = 20.

* AA - 2n=2x=20 - "Brassica rapa (syn. Brassica campestris)" - Turnip, Chinese cabbage
* BB - 2n=2x=16 - "Brassica nigra" - Black mustard
* CC - 2n=2x=18 - "Brassica oleracea" - Cabbage, kale, broccoli, cauliflower

These three species exist as separate species. But because they are closely related, it was possible for them to interbreed. This interspecific breeding allowed for the creation of three new species of tetraploid "Brassica". Because they are derived from the genomes of two different species, these hybrid plants are said to be allotetraploid (contain four genomes, derived from two different ancestral species). (Data from molecular studies indicate that the three diploid species are themselves paleopolyploids).Fact|date=July 2008

* AABB - 2n=4x=36 -"Brassica juncea" - Indian mustard
* AACC - 2n=4x=38 -"Brassica napus" - Rapeseed, rutabaga
* BBCC - 2n=4x=34 -"Brassica carinata" - Ethiopian mustard

References

Notes

Bibliography

* N. U. "Genome analysis in Brassica with special reference to the experimental formation of B. napus and peculiar mode of fertilization." Japanese Journal of Botany 7: 389-452 (1935).


Wikimedia Foundation. 2010.

Look at other dictionaries:

  • Triangle - получить на Академике рабочий купон на скидку Geekbuying или выгодно triangle купить с бесплатной доставкой на распродаже в Geekbuying

  • triangle — [ trijɑ̃gl ] n. m. • v. 1270; lat. triangulum 1 ♦ Figure géométrique, polygone plan à trois côtés. Les trois côtés, les trois sommets, les trois angles d un triangle. Triangle quelconque, scalène, isocèle, équilatéral. Triangle rectangle, qui a… …   Encyclopédie Universelle

  • Triangle — Tri an gle, n. [L. triangulum, fr. triangulus triangular; tri (see {Tri }) + angulus angle: cf. F. triangle. See {Angle} a corner.] 1. (Geom.) A figure bounded by three lines, and containing three angles. [1913 Webster] Note: A triangle is either …   The Collaborative International Dictionary of English

  • Triangle K — is a kosher supervision and certification organization under the leadership of Rabbis Jehoseph H. and Aryeh R. Ralbag.cite web url = http://www.trianglek.org/ title = Triangle K and Associates: Kosher Certification and Supervision accessdate =… …   Wikipedia

  • Triangle — ist ein 429 m hoch gelegener Ort mit etwa 2.000 Einwohnern in der Provinz Masvingo in Simbabwe; gelegen an der Straße und Eisenbahnlinie Mbizi Chiredzi. Triangle liegt in einer heißen und trockenen Region. Um landwirtschaftlichen Anbau zu… …   Deutsch Wikipedia

  • triangle — m. triangle > Triangle isocèle : triangle isocèle …   Diccionari Personau e Evolutiu

  • Triangle — Triangle, VA U.S. Census Designated Place in Virginia Population (2000): 5500 Housing Units (2000): 2318 Land area (2000): 2.633489 sq. miles (6.820706 sq. km) Water area (2000): 0.000000 sq. miles (0.000000 sq. km) Total area (2000): 2.633489 sq …   StarDict's U.S. Gazetteer Places

  • Triangle, VA — U.S. Census Designated Place in Virginia Population (2000): 5500 Housing Units (2000): 2318 Land area (2000): 2.633489 sq. miles (6.820706 sq. km) Water area (2000): 0.000000 sq. miles (0.000000 sq. km) Total area (2000): 2.633489 sq. miles… …   StarDict's U.S. Gazetteer Places

  • triangle — late 14c., from O.Fr. triangle (13c.), from L. triangulum triangle, from neut. of adj. triangulus three cornered, from tri three (see TRI (Cf. tri )) + angulus corner, angle (see ANGLE (Cf. angle) (n.)). In the huts of w …   Etymology dictionary

  • triangle — ► NOUN 1) a plane figure with three straight sides and three angles. 2) something in the form of a triangle. 3) a musical instrument consisting of a steel rod bent into a triangle, sounded with a rod. 4) an emotional relationship involving a… …   English terms dictionary

  • Triangle — Episodio de Buffy the Vampire Slayer Título Triángulo Identificador 5ABB011 Episodio nº 11 Temporada 5 …   Wikipedia Español

  • Triangle d'or — (le) région figurant un triangle, aux frontières du Laos, de la Thaïlande et de la Birmanie, ainsi nommée pour son importante production d opium …   Encyclopédie Universelle


Share the article and excerpts

Direct link
Do a right-click on the link above
and select “Copy Link”

We are using cookies for the best presentation of our site. Continuing to use this site, you agree with this.