J. Plieske et D. Struss, STS markers linked to Phoma resistance genes of the Brassica B-genome revealed sequence homology between Brassica nigra and Brassica napus, THEOR A GEN, 102(4), 2001, pp. 483-488
The RFLP and AFLP techniques are laborious and expensive and therefore of l
imited use for marker-assisted selection, demanding a high throughput of sa
mples in a short time. But marker-assisted selection is most useful for tra
its which are hard to score on single plants and influenced by environmenta
l factors. Four RFLP and three AFLP markers have been found to be linked to
genes of the B-genome of Brassica mediating resistance against Phoma linga
m in oilseed rape. One RFLP and one AFLP marker were converted into three P
CR-based STS markers: one of dominant, as well as one of codominant inherit
ance separated in a standard agarose gel and a third one of codominant inhe
ritance to be separated in a polyacrylamide gel on an automated sequencer.
As expected, the STS markers mapped at the same position as the original RF
LP and AFLP markers. The STS markers are efficient in marker-assisted backc
ross programs of the resistant B-genome/Brassica napus recombinant lines wi
th most of the tested oilseed rape varieties and breeding lines. More than
90% of the tested oilseed rape varieties and breeding lines exhibited no re
sistance marker alleles. The mapping results obtained with the markers, as
well as comparative sequencing of the marker alleles, indicate synteny and
homology between the B-genome resistance gene donors and B. napus in the re
gion of the resistance genes. The location of the resistance genes in the B
-genome/B. napus recombinant lines is most likely on the A genome. Thus the
transfer of the B-genome resistance genes into Brassica campestris is also
possible.