A History of Agriculture in India v1.c14.s2.7

v1.c14.s2.7

'The major wheat species of the world, and the one that contributes most to the annual harvest of 360 million tonnes, is still another kind, known generally as bread wheat. It is a hexaploid; that is, it has 21 pairs of chromosomes. It arose long after the initial domestication of the three primitive glume wheats. Its extra set of chromosomes was contributed by a wild goat-grass called *Triticum tauschii*, and the distribution of the wild progenitor suggests that the hybridization may have taken place somewhere near the southern end of the Caspian Sea. *T. tauschii* is the only species of goat-grass with a continental distribution, and it may have contributed to the adaptation that makes it possible for bread wheat to be grown on the dry steppes of the world. As a wild grass *T. tauschii* is essentially worthless, but as a contributor of genetic characteristics it literally made a billion-dollar crop out of a million-dollar one'.²