triticale of the genus X. Triticosecale, a new kind of cereal grain created by man. Its development began in 1876 when a Scottish botanist, A. Stephen Wilson, first managed to produce seedlings of an artificial cross between wheat and rye. The name ‘triticale’ is a combination of the botanical generic names of wheat (Triticum) and rye (Secale).
Such crosses occasionally occur naturally in the field, but the resulting hybrids are always sterile. Nevertheless, the prospect was attractive: a cereal with the superior bread-making properties of wheat and the hardiness of rye. Wilson’s plants were also sterile; but in 1891 a German, Rimpau, managed to produce partly fertile side shoots on an otherwise sterile plant. It was not until the 1930s that further progress was made. By this time more was known about genetics, in particular concerning the experimental doubling of chromosome numbers in plants, which could be done by treating them with the chemical colchicine.
Briefly, a normal plant is a diploid: it contains two half sets of chromosomes (genetic material): half of each of its parents’ chromosomes. Tetraploids, inheriting a full complement of chromosomes from each parent, and thus having double the normal allowance, occur in nature or can be induced. There are higher levels of ‘ploidy’: hexaploidy (three full sets), and octoploidy (four). All these polyploid plants have a tendency to grow to a large size: most cultivated wheats are hexaploids or tetraploids with seed heads far larger than their wild diploid ancestors. Furthermore, polyploidy is a way of overcoming the incompatibility of two insufficiently closely related plants whose chromosomes do not match each other, although it does not automatically result in a successful crossing with fertile offspring, as the early triticale breeding attempts showed.
By 1939, after seven years’ work with repeated crossing of hexaploids and octoploids, a German scientist, Müntzing, was getting promising results, and by 1950 he had produced plants with 90 per cent of the yield of wheat. From 1954 Shebeski and Jenkins at the University of Manitoba in Canada began intensive breeding. It became clear that the new grain was nutritionally as good as wheat and barley, and that it was possible to make bread with it. In 1970 the first commercial variety, Rosner, went on sale. Meanwhile, the International Centre for the Improvement of Maize and Wheat, in Mexico, produced new lines called Armadillo, which, when combined with Canadian strains, began to produce superior plants.
The latest kinds of triticale have good hardiness, very large seed heads, and are nutritionally better than wheat, having a higher content of lysine, an amino acid, in which wheat and other cereals are rather low. Triticale is a little weaker than wheat in gluten (the substance which gives wheat bread its firm texture), but with slightly altered preparation methods it is possible to make triticale bread of satisfactory texture. The flavour is stronger than that of wheat, not particularly like that of rye, but with a characteristic ‘nutty’ quality. Triticale bread, flour, and breakfast cereals have been made available so that consumers can try the new grain.
© the Estate of Alan Davidson 1999, 2006, 2014 © in the Editor’s contribution to the second and third editions, Oxford University Press 2006, 2014.