Schriften zu Genetischen Ressourcen - Genres

206
S. CHEBOTAR, M.S. RÖDER, V. KORZUN, M. GRAU and A. BÖRNER
primer pairs of wheat microsatellites with different chromosomal location were chosen
for analysis. PCR reactions and fragments detection were performed as described by
Röder et al. (1995, 1998).
The analyses of the stocks multiplied up to 24 times show a high degree of identity with
the most original material. No contamination due to foreign pollen or incorrect handling
during the multiplication cycles was discovered. For one accession (TRI 4599), some
genetic drift was observed whereas for TRI 249 a heterogeneous situation for two
markers was maintained over the years. The results indicate the high quality of maintenance
of self-pollinating genebank accessions in Gatersleben for more than 50 years.
Cross-pollinating species
From the Gatersleben rye (Secale cereale L.) collection, four accessions were analysed
up to now, regenerated 8, 12 (twice) or 14 times, respectively. Since the rye accessions
represent populations, 36 seeds from both the first and most recent regeneration cycle
of each accession were used for extracting DNA from single grains. Seven rye microsatellites
(RMS) were chosen for analysis. PCR reactions and fragments detection were
performed as described for wheat (RÖDER et al. 1995, 1998).
It was shown that in 26 of the 28 analysed accession/marker combinations less alleles
(nearly 50%) were discovered after regenerating the material. In 14 cases alleles were
found in the recent population, which were not observed in the investigated plants of the
original one. RMS makers turned out to differ in their efficiency. Whereas for RMS10
only five alleles were detected, RMS12 was shown to be much more polymorphic having
27 alleles. In continuation of the experiments, only highly informative RMS markers will
be utilised. As a conclusion from these results, the population sizes and field plot distances
used for the regeneration of cross-pollinating species should be reconsidered.
References
RÖDER, M.S., J. PLASCHKE, S.U. KÖNIG, A. BÖRNER, M.E. SORRELLS, S.D. TANKSLEY
and M.W. GANAL (1995): Abundance, variability and chromosomal location of microsatellites
in wheat. - Mol. Gen. Genet. 246, 327-333.
RÖDER, M.S., V. KORZUN, K. WENDEHAKE, J. PLASCHKE, M.-H. TIXIER, P. LEROY and
M.W. GANAL (1998): A microsatellite map of wheat. - Genetics 149, 2007-2023.