Brassica napus is highly polymorphic with cultivars selected for deferent purposes. Some are grown not for the root but for oilseeds and as leafy vegetables and forage crops.
These share names such as rape or kale with their diploid relatives.
Not until early in the 19th century can their stories be untangled from the diploid crops.
By them, they are widely grown as fodder and oil seeds crops in northern and eastern Europe.
Until very recently European rapeseed oil from Brassica napus was used mainly for illumination and lubricants.
Seeds of the old cultivars contained erucic acid, a long chain fatty acid, and other complex organic compounds that made the oil unsuitable for food used and the high protein meal unsuitable for livestock feed.
Breeders finally eliminated these undesirable compounds in the so-called double zero cultivars.
Since the 1930s, B. napus have become a major commercial oilseed crops in many European countries and Canada.
The bright yellow flowers of the extensive rape fields have become a dominant landscape feature of these regions.
B. napus was introduced to Japan in 1887. Subsequently, breeders there have synthesized the allopolyploid anew with the Chinese cabbage, instead of the turnip, as the source of the CC genomes.
The result is a heading cabbage-like B. napus. Like AACC hybrids synthesized by European plant breeders, all these new creations interbreed freely with the old B. napus cultivars.
The History of Brassica napus
