Table 1.

Summary of Genetic Changes among 47 Resynthesized S5 B. napus Allopolyploids

Marker TypeGenome Doubling
TotalSSRRFLPColch.aSpont.a
Total no. DNA fragments expectedb20,1673,02717,14016,7333,434
Total no. DNA fragments lost (%)713 (3.5)204 (6.7)509 (3.0)c610 (3.6)103 (3.0)
No. A fragments expectedbd7,5891,2536,3366,3011,288
No. A fragments lost (%)d308 (4.1)92 (7.3)216 (3.4)254 (4.0)54 (4.2)
No. C fragments expectedbd8,5971,4467,1517,1291,468
No. C fragments lost (%)d405 (4.7)112 (7.7)293 (4.1)356 (5.0)49 (3.3)
No. AC fragments expectedbd3,9813283,6533,303678
No. AC fragments lostd00000
  • a Method of allohaploid genome doubling. Colch., colchicine; Spont., spontaneously.

  • b Expected number of fragments is equal to the product of total markers scored and the number of lines, minus missing data, and is the number expected under parental additivity.

  • c In 71% of the 509 cases in which an RFLP fragment was lost, it was associated with intensification of a fragment from the other parental subgenome, suggesting that a loss/duplication had occurred. These data were not collected for SSR markers because PCR products are not easily quantifiable.

  • d Designations A (B. rapa), C (B. oleracea), and AC (common to both) indicate the genome of origin of the markers scored.