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Page 65 · DO #962 · 319_Love_Bx1FF7r
- Collection
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Áskell Löve (1916–1994) papers
- Item/Folder
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"Outlines for Books and Articles to be Published but Never Completed" (3 of 3)
- Digital Object
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DO #962,
page 65
- Collection-level dates
- 1950–1987
Page transcription
14, 28, and 42. They were discovered by T. Saha in Iran in 1918. The numbers are closely associated with differences in anatomy, morphology, resistance to disease, productiveness and milling and baking qualities. It is interesting to note that August Schultze, a German botanist, had arranged the wheats into these three groups in 1913, well before their chromosome numbers were known.
The 28- and 42-chromosome wheats have all arisen from 14-chromosome wheat and related grasses through hybridization followed by chromosome doubling. The cultivated wheats are the most conspicuous example of this evolution of polyploidy. It is the only known mechanism by which new true-breeding species can be created almost overnight.
Since different wild grasses have been involved in wheat's evolution, the species differ not only in the number but also in the nature of their chromosomes. Relationships of different sets of chromosomes are determined by studying the degree of chromosome pairing in the reproductive cells of hybrids. If the pairing is complete, or almost so, the chromosome sets (or genomes) of the parents are regarded as identical or closely related.