Plant Systematics and Evolution

, Volume 144, Issue 3, pp 209-220

First online:

Inferred chromosome morphology of the ancestral genome ofTriticum

  • J. DvořákAffiliated withDepartment of Agronomy & Range Science, University of California
  • , P. E. McGuireAffiliated withDepartment of Agronomy & Range Science, University of California
  • , S. MendlingerAffiliated withResearch and Development Authority, Ben Gurion University

Rent the article at a discount

Rent now

* Final gross prices may vary according to local VAT.

Get Access


The lengths of the A, B, and D genomes of common wheat,Triticum aestivum, were measured from the karyotype. Relative to the B genome, standardized as length 1.000, the lengths of the A and D genomes were 0.835 and 0.722, respectively. The lengths of the chromosome arms in the A and D genomes were then multiplied by the appropriate constants so that the total lengths of each genome also equalled 1.000. These calculations revealed that homoeologous chromosomes in wheat, with a few exceptions, have similar sizes and arm ratios. The arm lengths of the three homoeologues in each homoeologous group were then averaged. These average chromosomes turned out to be remarkably similar, in size and arm ratio, to their homoeologues in the E genome ofElytrigia elongata. This evidence and data on cross-compatibility and morphological characteristics suggested that the genusTriticum is a result of adaptive radiation from the perennial genusElytrigia, specifically from the complex of species possessing the E genome or one closely related to it.

Key words

Angiosperms Poaceae Triticum Elytrigia wheat Evolution genome karyotype