Chromosome structural changes in diploid and tetraploid A genomes of Gossypium

Genome. 2006 Apr;49(4):336-45. doi: 10.1139/g05-116.


The genus Gossypium, which comprises a divergent group of diploid species and several recently formed allotetraploids, offers an excellent opportunity to study polyploid genome evolution. In this study, chromosome structural variation among the A, At, and D genomes of Gossypium was evaluated by comparative genetic linkage mapping. We constructed a fully resolved RFLP linkage map for the diploid A genome consisting of 275 loci using an F2 interspecific Gossypium arboreum x Gossypium herbaceum family. The 13 chromosomes of the A genome are represented by 12 large linkage groups in our map, reflecting an expected interchromosomal translocation between G. arboreum and G. herbaceum. The A-genome chromosomes are largely collinear with the D genomes, save for a few small inversions. Although the 2 diploid mapping parents represent the closest living relatives of the allotetraploid At-genome progenitor, 2 translocations and 7 inversions were observed between the A and At genomes. The recombination rates are similar between the 2 diploid genomes; however, the At genome shows a 93% increase in recombination relative to its diploid progenitors. Elevated recombination in the Dt genome was reported previously. These data on the At genome thus indicate that elevated recombination was a general property of allotetraploidy in cotton.

Publication types

  • Comparative Study
  • Evaluation Study
  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Chromosome Inversion
  • Chromosome Mapping / methods
  • Chromosome Segregation
  • Chromosomes, Plant / metabolism*
  • Gene Dosage*
  • Genes, Duplicate
  • Genetic Linkage
  • Genetic Markers
  • Genome, Plant*
  • Gossypium / genetics*
  • Polymorphism, Restriction Fragment Length
  • Synteny
  • Translocation, Genetic


  • Genetic Markers