Photoperiod insensitive Ppd-A1a mutations in tetraploid wheat (Triticum durum Desf.)

Theor Appl Genet. 2009 Jan;118(2):285-94. doi: 10.1007/s00122-008-0898-9. Epub 2008 Oct 7.


Variation in photoperiod response plays an important role in adapting crops to agricultural environments. In hexaploid wheat, mutations conferring photoperiod insensitivity (flowering after a similar time in short or long days) have been mapped on the 2B (Ppd-B1) and 2D (Ppd-D1) chromosomes in colinear positions to the 2H Ppd-H1 gene of barley. No A genome mutation is known. On the D genome, photoperiod insensitivity is likely to be caused by deletion of a regulatory region that causes misexpression of a member of the pseudo-response regulator (PRR) gene family and activation of the photoperiod pathway irrespective of day length. Photoperiod insensitivity in tetraploid (durum) wheat is less characterized. We compared pairs of near-isogenic lines that differ in photoperiod response and showed that photoperiod insensitivity is associated with two independent deletions of the A genome PRR gene that cause altered expression. This is associated with induction of the floral regulator FT. The A genome deletions and the previously described D genome deletion of hexaploid wheat remove a common region, suggesting a shared mechanism for photoperiod insensitivity. The identification of the A genome mutations will allow characterization of durum wheat germplasm and the construction of genotypes with novel combinations of photoperiod insensitive alleles.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Genotype
  • Mutation*
  • Photoperiod*
  • Plant Proteins / chemistry
  • Plant Proteins / genetics*
  • Plant Proteins / physiology
  • Polymorphism, Genetic
  • Polyploidy*
  • Sequence Analysis, DNA
  • Time Factors
  • Triticum / genetics*
  • Triticum / physiology
  • Triticum / radiation effects


  • Plant Proteins