Brassica oleracea

Brassica oleraceais a plant of the familyBrassicaceae, also known aswild cabbagein its uncultivated form. The species evidently originated fromferalpopulations of related plants in theEastern Mediterranean, where it was most likely first cultivated. It has many commoncultivarsused as vegetables, includingcabbage,broccoli,cauliflower,kale,Brussels sprouts,collard greens,Savoy cabbage,kohlrabi, andgai lan.
WildB. oleraceais a tallbiennialorperennialplantthat forms a stoutrosetteof largeleavesin the first year. The grayish-green leaves are fleshy and thick,helping the plant store water and nutrients in difficult environments. In its second year, a woody spike grows up to 1.5 metres (5 ft) tall, from which branch off stems with long clusters of yellow four-petaled flowers.
According to theTriangle of Utheory,B. oleraceais very closely related to five other species of the genusBrassica.A 2021 study suggests thatBrassica cretica, native to the Eastern Mediterranean, particularly Greece and theAegean Islands, was the closest living relative of cultivatedB. oleracea, thus supporting the view that its cultivation originated in the Eastern Mediterranean region, with later admixture from otherBrassicaspecies.Genetic analysis of nine wild populations on the French Atlantic coast indicated their commonferalorigin, deriving from domesticated plants escaped from fields and gardens.
The cultivars ofB. oleraceaare grouped by developmental form into several majorcultivar groups, of which theAcephala ("non-heading") groupremains most like the natural wild cabbage in appearance.
'Brassica' wasPliny the Elder's name for several cabbage-like plants.
Itsspecific epithetoleraceameans "vegetable/herbal" inLatinand is a form ofholeraceus(oleraceus).
Although rarely abundant, wild cabbage is found on the coasts of Britain, France, Spain, and Italy.
Wild cabbage is ahardyplant with high tolerance forsaltandlime. Its intolerance of competition from other plantstypically restricts its natural occurrence to limestone sea cliffs, like the chalk cliffs on both sides of theEnglish Channel.
B. oleraceahas become established as an important human foodcropplant, used because of its large food reserves, which are stored over the winter in its leaves. It has been bred into a wide range ofcultivars, including cabbage, broccoli, cauliflower, brussels sprouts, collards, and kale, some of which are hardly recognizable as being members of the same genus, let alone species.The historical genus ofCrucifera, meaning "cross-bearing" in reference to the four-petaled flowers, may be the only unifying feature beyond taste.
Researchers believe it has been cultivated for several thousand years, but its history as a domesticated plant is not clear beforeGreekandRomantimes, when it was a well-established garden vegetable.Theophrastusmentions three kinds ofrhaphanos(ῤάφανος):a curly-leaved, a smooth-leaved, and a wild-type.He reports the antipathy of the cabbage and the grape vine, for the ancients believed cabbages grown near grapes would impart their flavour to the wine.
Throughartificial selectionfor various phenotype traits, the emergence of variations of the plant with drastic differences in appearance occurred over centuries. Preference for leaves,terminal buds,lateral buds, stems, andinflorescencesresulted in selection of varieties of wild cabbage into the many forms known today. The wild plant (and its ancestors) originated in the eastern Mediterranean region of Europe. Estimated fromSanskritwritings 4,000 years ago, as well as Greek writings from the sixth century BC, plant cultivation may have occurred.
The preference for eating the leaves led to the selection of plants with larger leaves being harvested and their seeds planted for the next growth. Around the fifth century BC, the formation of what is now known as kale had developed.Preference led to further artificial selection of kale plants with more tightly bunched leaves or terminal buds. Around the first century AD, the phenotype variation ofB. oleraceaknown as cabbage emerged.Phenotype selection preferences in Germany resulted in a new variation from the kale cultivar. By selecting for wider stems, the variant plant known askohlrabiemerged around the first century AD.
European preference emerged for eating immature buds, selecting forinflorescence. Early records in 15th century AD, indicate that earlycauliflowerandbroccoliheading types were found throughout southern Italy and Sicily, although these types may not have been resolved into distinct cultivars until about 100 years later.Further selection in Belgium in lateral bud led toBrussels sproutsin the 18th century.
According to the Royal Botanic Gardens (Kew Species Profiles)the species has eightcultivar groups. Each cultivar group has manycultivars, like 'Lacinato' kale or 'Belstar' broccoli.
A 2024 study compares 704B. oleraceasequences and establishes aphylogenetic treeof cultivars. The authors find large-scale changes in gene expression and gene presence. Some genes are considered to be linked to certain traits such as arrested inflorescence (typical of cauliflower and broccoli).
TheTAS2R38gene encodes aG protein-coupled receptorthat functions as a taste receptor, mediated by ligands such aspropylthiouracil(PTU) andphenylthiocarbamidethat bind to the receptor and initiate signaling that confers various degrees of taste perception.Vegetables in the brassica family, such as collard greens, kale, broccoli, cabbage, and Brussels sprouts, containglucosinolatesandisothiocyanates, which resemble PTU, and therefore much of the perceived "bitterness" of these vegetables is mediated through TAS2R38.Bitter taste receptors in the TS2R family are also found in gut mucosal and pancreatic cells in humans and rodents. These receptors influence release of hormones involved in appetite regulation, such aspeptide YYandglucagon-like peptide-1, and therefore may influence caloric intake and the development of obesity. Thus, bitter taste perception may affect dietary behaviors by influencing both taste preferences and metabolic hormonal regulation.
Three variants in the TAS2R38 gene –rs713598,rs1726866, andrs10246939– are in highlinkage disequilibriumin most populations and result in amino acid coding changes that lead to a range of bitter taste perception phenotypes. The PAVhaplotypeis dominant; therefore, individuals with at least one copy of the PAV allele perceive molecules in vegetables that resemble PTU as tasting bitter, and consequently may develop an aversion to bitter vegetables. In contrast, individuals with two AVI haplotypes are bitter non-tasters. PAV and AVI haplotypes are the most common, though other haplotypes exist that confer intermediate bitter taste sensitivity (AAI, AAV, AVV, and PVI). This taste aversion may apply to vegetables in general.