Wheat is the staple food of millions of people, being one of the three globally produced Cereals (Maize and Barley being the other two). Although rice is the second largest produced cereal in the world, its production is localised to Western and Eastern Asia. The cultivation of wheat was started some 10,000 years ago, with its origin being traced back to south east Turkey. It was called Einkorn (T. monococcum) and genetically is described as a diploid, containing two sets of chromosomes. At a similar time Emmer wheat (Triticum dicoccum) was being domesticated.
This was a further genetic development as Emmer was a natural hybridization between two wild grasses - Triticum urartu (closely related to wild einkorn (T. boeoticum), and an Aegilops species. Both of these were diploids which meant that this new wheat was now a tetraploid, i.e. it had four sets of chromosomes. Durum wheat is also a tetraploid and developed through a natural hybridization just as Emmer wheat did. Over the years farmers continued to make selections from their fields of wheat’s that showed favourable traits – ease of harvest, yield etc. and new wheat’s started to dominate.
Spelt and Common bread wheat became the favoured types. These two were again the result of a natural hybridization between Emmer wheat and the wild goat-grass Aegilops tauschii. This hybridization took the tetraploid to an hexaploid, now containing six sets of chromosomes (i.e. 42 chromosomes), somewhat different to the 14 in the original species. This ‘natural’ genetic development, whilst being highly successful, has taken many years so biotechnology is now exploring the ways that genetic management can be done faster and more efficiently with very targeted gene manipulation.