Schriften zu Genetischen Ressourcen - Genres

Molecular mapping and geographical distribution of genes determining anthocyanin pigmentation
computer program (LANDER et al. 1987); QTL-analysis was performed using the
QGENE application (NELSON 1997).
Genetic mapping
The phenotypic segregation data, obtained from scoring F2 or F3 populations gave clear
indication for a monogenic inheritance of the target trait as proven by χ 2 -test. From the
wheat microsatellites tested, 20 out of 31 (chromosome 7A; 65%), 23 out of 34 (chromosome
7B; 68%) and 11 out of 26 (chromosome 7D; 42%) were found to be polymorphic
between the parents. The three coleoptile colour genes were mapped about 15 to
20 cM distal from the centromere on the short arms of the homoeologous group 7 chromosomes.
Since the map positions of all three genes are highly comparable it may be
concluded that they are members of a homoeologous series. According to the rules for
the symbolisation of genes in homoeologous sets, we propose to designate the group 7
red coleoptile colour genes as Rc-A1, Rc-B1 and Rc-D1, respectively. Further homoeologous
loci may exist on chromosome 7R in Secale cereale (an1) and on chromosome
7H in Hordeum vulgare (ant1). When analysing the ITMI population, two QTLs
were mapped within intervals, highly comparable to the regions where the major genes
in the F2/F3 mapping studies were detected. It could be suggested that the A genome of
Triticum durum and the D genome of Aegilops tauschii are carrying homoeologous loci
determining red coleoptile colour.
Geographical distribution
Most of the 468 varieties tested, about 60% (273), were found having non coloured coleoptiles,
whereas in 23% (107) and 6% (26) of the wheat genotypes red and dark red
coloured coleoptiles, respectively, were detected. Sixty-two varieties (13%) were segregating.
The highest percentage of varieties with red coloured coleoptiles was found in
material from the United Kingdom (62%), followed by France (38%) and Germany
(28%). High frequencies of segregating varieties were discovered in material from the
Ukraine (25%) and France (23%). Interestingly, the frequency of varieties having red
coloured coleoptiles was lower in Southern and Eastern Europe compared to Western
European countries. A list with the results for all tested varieties is presented by
KHLESTKINA et al. (2001).
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