On the 8th and 9th September we welcomed members of the public to join us for our annual Heritage Open Day event in the John Innes Historical Collections. Heritage Open Days represent England’s biggest heritage festival, and like venues all across Norwich and Norfolk we were joining in the celebration of our history and culture. For these special HODs events we like to not only display a new theme using our fantastic rare books and archives, but also bring in one of our John Innes Centre scientists to tell us about their research. This year we were very lucky to have Dr Judith Irwin from JIC’s Crop Genetics Department talking about ‘Our Ancient and Diverse Brassica Vegetables’- a fascinating tour of more than 2000 years of history of cultivation and study, brought up to date with Judith’s research on flowering time in broccoli.
Judith began her talk with a survey of the brassicas which are part of the mustard family. The mustards are a very large family of more than 300 genera and 3,500 species. In traditional botanical classification the mustards are part of the Crucifer family (having four petals arranged in a cross). Judith told us that a good place to see the wild brassica ancestor of many of our garden brassica vegetables (Brassica oleracea subspecies oleracea) are the chalk cliffs of Dorset where you’ll see their clumps of yellow flowers. We’re not sure whether this species is genuinely native to the UK or a garden escape. Studies of the plant geography suggest an origin in the Irano-Turanian region, possibly centred on Turkey – but this has not yet been confirmed. A flora of Turkey published in 2007 listed 560 species of Brassicaceae in all.
The origins of our cultivated brassicas were probed further by a Korean-Japanese botanist who was working in Japan called Dr U (his name Woo Jang-choon is today known by the Japanized reading of his name ‘Nagaharu U’) who in 1935 came up with what is now known as ‘U’s triangle’- a diagram of the relationships between the different cultivated brassica species. U showed that oilseed rape and swede (Brassica napus) is a hybrid between two other species: Brassica rapus (turnip, Chinese cabbage, turnip rape) and Brassica oleracea (cabbage, sprouts, broccoli, and cauliflower).
Judith then moved on to tell us about the ancient history behind brassica vegetables, from descriptions by the Greek philosopher Theophrastus (370-285 BC) to the book on farming by Roman author Cato the Elder (234 BC to 149 BC) who stated ‘Cabbage surpasses all vegetables. Eat it either cooked or raw. If you eat it raw, dress it with vinegar. It aids digestion remarkably’. It has been suggested that our brassica vegetables originate with the Romans bringing cabbage to the British Isles (Gates 1950), and we know that the Anglo-Saxons cultivated brassicas because they actually called the month of February ‘sprout-kale’ (Wright, 1968). Brassica vegetables were cultivated extensively by medieval religious orders for food and medicine. Much of the knowledge they used probably came down to them from classical sources. Pliny the Elder (AD 23 to AD 79), for example, described a list of more than 80 cabbage-related medicines. The oldest herbals in the John Innes Historical Collections date from the 16th and 17th centuries and are full of advice on how to use brassicas for improving health and curing ailments. We displayed, for example, the popular herbal by Nicholas Culpeper (1616-1654) which listed many Cabbage–based remedies including: Adder bites, hoarseness of the voice, kidney stones, drunkenness, gout and many more.
Judith went on to discuss which of our brassica vegetables came first. We think the first brassica crops grown here were the more primitive kales, or ‘collards’. The word ‘collard’ is a corruption of the Anglo-Saxon word ‘colewort’ – their word for cabbage plants. In the Latin species name Brassica oleracea acephala, acephala means ‘without a head’. Kale has been grown for more than 2000 years: the Romans grew several kinds, and the Celts of central and Western Europe also grew them.
The next brassicas to arrive were the cabbages: the species name Brassica oleracea capitata meaning ‘head’. Our common name ‘Cabbage’ is the anglicised form of the old French word caboce or caboche – also meaning ‘head’. The Celtic word ‘bresic’ for cabbage, is said to have influenced the Latin name brassica.
We know that cabbages were grown in 14th century England because we have a recipe ascribed to the chief cook to King Richard II for “caboches in potage”, this instructs the reader to take caboches and quarter them – see the original recipe here. The commercial cultivation of cabbages in England came later- probably introduced from Holland in the 16th century by Sir Anthony Ashley. By this time cabbages and turnips had also reached North America. French Navigator Jacques Cartier is thought to have brought the seeds with him on his third voyage for use by the settlement he established in Canada.
Next came the Kohl rabi from the German Kohl for ‘cabbage’ and Rabi for ‘turnip’ with the species name Brassica oleracea gongloydes – the ‘gongloydes’ meaning roundish or swollen, these are thought to have appeared in the 16th century. Other 16th century novelties included the cauliflowers and broccolis. Cauliflower from the Latin ‘caulis’ (cabbage) and floris (flower) – the species name Brassica oleracea botrytis is taken from the Greek meaning like a bunch of grapes. The ‘broccoli’ name refers to its branching character (‘brachium’- an arm or branch). In 1586 broccoli’s were referred to as the ‘Cyprus coleworts’, while the Latin name for them is Brassica oleracea italica (from Italy).
Finally, the Brussels sprouts arrived (Brassica oleracea gemmifera) – ‘gemmifera’ meaning ‘diamond maker’ (giving the idea perhaps that eating them made you mentally alert!). These are generally believed to have evolved in the seventeenth or eighteenth century and originated, as the name suggests, from Brussels. Judith rounded off this discussion with some slides taken from the John Innes’s collection of seed catalogues which cover the 19th and early 20th centuries.
These show that seed firms recommended kale to growers as a frost hardy crop that could be relied on when other greens were scarce or destroyed. Cauliflower was ‘rather tender’ and so was sown in spring for autumnal use, whereas broccoli was hardier and suitable for growing through winter for use in spring and summer. Judith drew attention to some of the varietal names for ‘Broccoli’ in the catalogues. For example, ‘Bunyard’s Early White’, ‘Bunyard’s April White’, and ‘Snow’s Winter White’ – showing that at this time (aside from the Purple Sprouting Broccoli) the headed ‘broccoli’ known to the English grower at that time was white not green. To re-inforce the point Judith showed a clip from a 1950s film showing the Spring ‘broccoli harvest’ in West Cornwall- the vegetables in the field clearly looking like cauliflowers (and on the day this was filmed 12 special trains were laid on to transport the ‘broccoli’ to London). Calabrese (what we now call the green headed broccoli in our greengrocers) appeared in our 1935 and 1949 English and American seed catalogues as a novel Italian import.
The second part of Judith’s talk focused on modern brassica research. Research on brassica is first mentioned in the John Innes archives in the papers of A J Bateman who used them as part of his experiments to work out the isolation distances for seed crops (working out how far apart you needed to grow crops to keep them from intercrossing – to keep the seed ‘pure’). This research helped the seed growers reduce the land area they needed to raise crops for seed. In 1948 Bateman was also studying hybrids between different brassica species, and his records include one of the old ‘crossing tags’ that were used to mark up the experimental plants.
After that era brassicas only become a major part of JIC’s research in the late 1980s when a Brassica and Oilseeds Department was set up shortly before the closure of the Plant Breeding Institute in Cambridge. A lot of the work introduced by the arrival of the ex-PBI staff centred on the model plant Arabidopsis thaliana – with its simpler genome and fast life-cycle, and compact form, it is a more convenient plant to work with to study genetics than the brassica species, to which the findings can later be applied. The more complex cabbages and cauliflowers have 3 times more genes and oilseed rape 6 times more to study.
Judith’s research focuses on how temperature influences flowering. Why do we want to do this? Judith explained that climate change will affect when plants flower, and it is also important for crop scheduling (having crop plants ready to harvest across the season to provide efficient harvesting and reduce waste). Judith showed some examples of how spells of extreme cold had wrecked brassica harvests in the recent past. Judith is interested in winter temperature and how plants tell the seasonal day length. Broccoli plants count the number of cold days they’re exposed to because they have a ‘vernalization requirement’ meaning they need a period of prolonged cold in order to flower. Temperature is central to any brassica you grow. The fundamental research on what controls flowering time here at JIC centres on the work of Dame Professor Caroline Dean, FRS whose work on Arabidopsis has produced so much of the ‘road map’ to understanding how flowering time in brassicas works.
Judith’s work, in collaboration with Professor Dean, plant breeders and growers, involves crossing different broccoli lines together to find the gene controlling the trait for how many days of cold (and how cold) the plant needs before it can flower. Their objective is to breed different varieties of broccoli that will be ready to harvest at different times.
The difficulty comes in the fact that the genes controlling flowering are also involved in many other plant characters (including the seeds and pods) – it is important not to adversely affect these commercial traits when producing new brassica varieties with changed responses to cold. The future challenge is to ‘climate-proof’ our crops: to produce crops with defined, predictable flowering times; uniform and shortened flowering period; more determinate flowering habit; and uniform harvest with reduced losses (by breeding for reduced cold sensitivity) for agricultural and horticultural crops and for seed and commercial production. Achieving this goal will require an integrated view across plant development as a whole, and how this is affected by the environment. Judith gave the audience an insight into some of the equipment required to take this research forward, from the state of the art controlled environment rooms at JIC (taking the weather to the plant rather than the plant to the weather) to photo-booths (at the University of Aberystwyth) used to document an individual plant’s growth and development from the start to the end of their life-cycle, a process that can then be digitally modelled. I’m sure everyone enjoyed the talk and its fascinating insights into 2000 years of brassica history.
Garden catalogues on display from the John Innes Centre Archives:
George Bunyard and Co. Ltd., Vegetables for Epicures n.d. [c. 1939-1945] (Maidstone, Kent)
Carter’s Tested Seeds Ltd, The Blue Book of Gardening, Catalogues 1939 and 1949 (Raynes Park, London).
S. Daniel’s & Son, Ltd. Catalogue, Spring, 1931 (Wymondham, Norfolk)
Henry A. Dreer, Dreer’s Garden Book 1935 (Philadelphia, PA, USA)
Edmunds (Milton) Ltd, Edmunds Bulbs, Seeds, and Plants Catalogue 1931 (Milton, Cambridgeshire)
Elsoms (Spalding) Ltd, Seeds of Quality Catalogue, December 1943 (Spalding, Lincolnshire)
For a brief history of cabbages:
R. Gates, ‘Wild cabbages and the effects of cultivation’, Journal of Genetics (1950) 51: 363-372
D. Mitchell, ‘The status of Brassica oleracea L. Subsp. Oleracea’ (wild cabbage) in the British Isles’, Watsonia (1976) 11: 97-103.
Jonathan Roberts, Cabbages and Kings: the Origins of Fruit and Vegetables (London: HarperCollins, 2001).
Lawrence Wright (1968). Clockwork Man London: Elek Books Ltd., p. 43. See more here
For more information about Judith Irwin’s lab and their work on brassicas at JIC follow the link.
For U’s classic paper and the now famous ‘U’s triangle’, See Nagaharu U (1935): “Genome analysis in Brassica with special reference to the experimental formation of B. napus and peculiar mode of fertilization”. Japan. Journal of Botany, 7: 389–452.