The Triangle of U is a theory which describes the evolution and relationships between members of the plant genus Brassica. The theory centers around the idea that initially there were three different ancestral genomes that combined, in various configurations, to create many of the common vegetables and oilseeds we know today. Divisions Green algae Land plants (embryophytes) Non-vascular embryophytes Hepatophyta - liverworts Anthocerophyta - hornworts Bryophyta - mosses Vascular plants (tracheophytes) Seedless vascular plants Lycopodiophyta - clubmosses Equisetophyta - horsetails Pteridophyta - true ferns Psilotophyta - whisk ferns Ophioglossophyta - adderstongues Seed plants (spermatophytes) †Pteridospermatophyta - seed ferns Pinophyta - conifers Cycadophyta - cycads Ginkgophyta - ginkgo Gnetophyta - gnetae Magnoliophyta - flowering plants... See genus (mathematics) for the use of the term in mathematics. ... Species See text Brassica is a plant genus, in the cabbage family (Cruciferae, also known, more fashionably, as the Brassicaceae). ... Genome is also a popular science book by Matt Ridley. ... Vegetables on a market Vegetable is a nutritional and culinary term denoting any part of a plant that is commonly consumed by humans as food, but is not regarded as a culinary fruit, nut, herb, spice, or grain. ... Vegetable oil or vegoil is fat extracted from plant sources. ...

The triangle contends that many 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 variety. The letter n denotes the number of chromosomes in each genome. For example Brassica rapa has an AA - n=10 designation. That means each cell contains two complete genome copies, (diploid) and each genome has ten chromosomes. Thus each cell will contain 20 chromosomes. Image File history File links A simple diagram of the Triangle of U. This triangle is a theoretical explaination for the origin of many common Brassica species. ... Species See text Brassica is a plant genus, in the cabbage family (Cruciferae, also known, more fashionably, as the Brassicaceae). ... In biology the genome of an organism is the whole hereditary information of an organism that is encoded in the DNA (or, for some viruses, RNA). ... Diploid (meaning double in Greek) cells have two copies (homologs) of each chromosome (both sex- and non-sex determining chromosomes), usually one from the mother and one from the father. ... This article is about the biological chromosome. ... Figure 1: Chromosome. ...

• AA - n=10 - Brassica rapa - Turnip, Chinese cabbage
• BB - n= 8 - Brassica nigra - Black mustard
• CC - n= 9 - Brassica oleracea - Cabbage, kale, broccoli

Initially, these three species would have existed as isolated relatives. But because they are so closely related it was possible for them to interbreed. This interspecific breeding allowed 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 different parent species). Binomial name Brassica rapa L. Brassica rapa is a plant species widely distributed through temperate climates as a weed, and widely cultivated as a leaf vegetable, a root vegetable, and an oilseed. ... Turnip can refer to two vegetables, which are described under the articles Turnip (brassica rapa) and Rutabaga. ... Trinomial name Brassica campestris L. pekinensis Bok choy (Brassica campestris, Chinese 白菜 báicài) is an Asian relative of the common cabbage. ... Binomial name Brassica nigra L. Black mustard (Brassica nigra) is an annual weedy plant cultivated for its seeds, which are commonly used as a spice. ... Binomial name Brassica nigra L. Black mustard (Brassica nigra) is an annual weedy plant cultivated for its seeds, which are commonly used as a spice. ... Binomial name Brassica oleracea L. See also cabbage Brassica oleracea or Wild Cabbage, is a species of Brassica native to coastal southern and western Europe, where its resistance to salt and lime but intolerance of competition from other plants typically restricts is natural occurrence to limestone sea cliffs. ... Cultivar Group Brassica oleracea Capitata Group The cabbage (Brassica oleracea Capitata Group) is an edible plant of the Family Brassicaceae (or Cruciferae). ... Lacinato Kale (left) with Collard greens (right) Kale is a form of cabbage (Brassica oleracea Acephala Group) in which the central leaves do not form a head. ... Cultivar Group Brassica oleracea Italica Group Broccoli is a plant of the Cabbage family, Brassicaceae (formerly Cruciferae). ... In biology, hybrid has three meanings. ... Polyploid (in Greek: πολλαπλόν - multiple) cells or organisms contain more than two copies (ploidy) of their chromosomes. ...

• AABB - n=18 -Brassica juncea - Indian mustard
• AACC - n=19 -Brassica napus - Rapeseed, rutabaga
• BBCC - n=17 -Brassica carinata - Ethiopian mustard