Genetic Modification (GM) has been very successful with maize, rice and soya, but
much less so with wheat, mainly due to the fact that most wheat varieties are
genetically. 200 million acres of GM crops were grown in 2004, with positive
results in regard to yield, pesticide use, biodiversity and costs—and no negative
effects on human health. Yet GM continues to face strong opposition from the
environmental movement. The irony of this is that GM was invented in 1983 as a
safer and more gentle approach than the existing methods of generating mutant,
possibly useful, plant types. These methods include irradiation, x-rays, thermal
neutrons and ethyl methane sulphonate to damage DNA and produce random
mutations, while with GM scientists can add the specific attributes they want in a
more or less predictable way—indeed, in a more “organic” method of manipulating
genes to introduce desirable characteristics. The jury is out ...
As early as 1956 irradiation was used at the Atomic Energy Research
Establishment at Harwell, Oxford, UK on a barley variety called Maythorpe. This
gave rise to barley strains with shorter, stiffer straw but also with the same desirable
characters of early maturity and malting quality, culminating finally in the release of
Golden Promise.
Gramineae family—the grasses. The “pseudo-cereals” are from other plant families,
such as Amaranthaceae (Amaranths), Chenopodiaceae (Quinoa) and Polygonaceae
(Buckwheat). They are often regarded as cereals because their seeds are similar
nutritionally to those of the true cereals; their importance is slowly dwindling in
comparison to the “true” cereals.
The great success of the cereal species is due to a number of factors: they adapt
well to a wide range of soil types, climates and cultivation methods; they are
relatively efficient in photosynthesis; they are all annuals; they are relatively hardy
(tolerant of cold, and other factors) and they recover well from damage. Most
important of all, their grain is contained in a neat package of stored energy which is
convenient to harvest, and which is easy to handle, clean and store.
Cereal grain is an important source of carbohydrate, fibre (insoluble and
soluble), some vitamins (B complex and E) and minerals. The fat content is about
2% (up to 7%, in dehusked oats), and highly unsaturated—maize (corn) oil is widely
traded and consumed throughout the world. The iron content of Teff is an
impressive 80–90 mg iron per 100 g. Some cereals provide useful amounts of
calcium; finger millet grain for example contains about 350 mg/100 g.
On the negative side, cereal grains are deficient in a number of Vitamins. The
dry grain contains no B 12 nor C, and very little A, D, K or B 2 (Riboflavin). In
general the quality of protein in cereal grain is also poor; all of the cereals are
deficient primarily in lysine with a secondary deficiency in threonine or tryptophan.
There has been some progress with breeding high lysine varieties of maize.
The most important cereal crops are maize, wheat and rice, which in global
terms produce approximately 80% of the total production of grain cereals. Most of
the other 20% is produced from the cereal crops described in the following pages:
barley, buckwheat, millets, oats, rye, sorghum and teff.
hexaploid—six copies of each gene—and are consequently more difficult to modify
The true cereals, which produce a grain type of fruit, are all members of the