Estimates of the Homoeology of Wheat Chromosomes by Measurements of Differential Affinity at Meiosis

  • Ralph Riley
  • Victor Chapman


The chromosome complement of the hexaploid wheat of commerce, Triticum aestivum (2n = 6x = 42), can be classified into seven homoeo-logous groups, each of three pairs, or into three genomes, each of seven pairs. The genomes represent the sets of chromosomes combined together—from three distinct diploid species—during the allopolyploid evolution of wheat. The 14-chromosome, diploid, ancestors of T. aestivum were Triticum monococcum, Aegilops speltoides and Aegilops squarrosa, or their close relatives—the contributors of the A, B and D genomes respectively (McFadden and Sears, 1944; Riley, Unrau and Chapman, 1958).


Wheat Chromosome Marked Chromosome Homoeologous Group Homoeologous Chromosome Chiasma Formation 
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Copyright information

© Ralph Riley and K. R. Lewis 1966

Authors and Affiliations

  • Ralph Riley
    • 1
  • Victor Chapman
    • 1
  1. 1.Plant Breeding InstituteCambridgeEngland

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