TABLE 4

Comparison of de novo viable HNRT frequencies generated during meiosis of haploid vs. euploid lines

Linkage group carrying the HNRTOrigin of duplicated segmentProgenies (female × male)Interval observedNo. of de novo HNRTs detectedMean no. of de novo HNRTs per plantRatioab
Top N1Top N11Haploid × euploidCB10081b–Brass02660.05212**
Euploid × euploid (Udall et al. 2005)pW169d–pX128e60.009
Top N11Top N1Haploid × euploidCB10081a–Na12C08140.12132**
Euploid × euploid (Udall et al. 2005)pW125c–pC128g50.008
Top N18Top N9Haploid × euploidCB10092–JLP04270.080106**
Euploid × euploid (Udall et al. 2005)pW123d–pW22710.002
Bottom N3Bottom N13Haploid × euploidBrass29–Cz4A2795000.000
Euploid × euploid (Udall et al. 2005)pW147b–pX136a00.000
  • a This ratio, which reflects the rate of increase of haploid vs. euploid homeologous recombination, is estimated by dividing twice the mean number of de novo HNRTs per plant detected in the haploid × euploid progenies by the mean number of de novo HNRTs per plant detected in the euploid × euploid progenies (data from Udall et al. 2005). Magnification of the numerator by a factor of 2 aims at compensating for the presence of two homologous chromosomes in the euploids while there is only one in the haploids.

  • b χ2-tests were performed to compare the relative proportion of homologous and homeologous recombinants at each location: **P < 1%; *P < 5%.