A Database for Triticeae and Avena
INSTITUT FÜR PFLANZENGENETIK UND KULTURPFLANZENFORSCHUNG
Corrensstraße 3, 06466 Gatersleben, Germany.
A. Börner, A. Bálint, K.F.M. Salem, E. Pestsova,
M.S. Röder, and E.K. Khlestkina.
Copper tolerance. [p. 28]
We evaluated a new testing method to screen for copper tolerance
in wheat genetic stocks in the greenhouse. Three copper concentrations
(1,000, 1,500, and 2,000 mg/kg) were tested on two hexaploid-wheat
genotypes (Chinese Spring and synthetics) to find a suitable concentration
for the screening. We found that copper concentrations between
1,000-1,500 mg/kg in the soil are most efficient for testing.
Copper tolerance was evaluated by calculating the tolerance index.
Using wheatrye substitution lines (T. aestivum
cultivar Saratovskaya 29 and S. cerale cultivar Vietnamskaya),
we found significant effects for copper tolerance. Rye chromosome
5R (5R/5A substitution line) increased copper tolerance, which
was significant at P = 0.01 level, whereas rye chromosome 1R had
no effect. This result reinforced the idea that wheat chromosome
5A plays a role in reducing the toxic effect of copper. In the
coming season, we will screen other wheat genetic stocks available
at IPK Gatersleben (ITMI-mapping population, T. aestivum-Ae.
tauschii introgression lines) to detect the QTL that determine
Stem reserve mobilization. [p. 28]
A selection of 12 tetraploid and two hexaploid wheat accessions
was grown in the field and evaluated for the ability to mobilize
stored stem reserves. We used a method for the chemical desiccation
of the plant canopy for this investigation. In one replication,
the canopies were sprayed with potassium iodide (0.5 %) 2 weeks
after anthesis. In order to calculate the rate of reduction in
grain weight caused by the treatment, the 1,000-kernel weight
of the treated plants was compared with that of the controls after
harvest. The percentage reduction ranged between 33.80 % and 77.97
% (Table 1).
Table 1. Reduction in grain weight in tetraploid
and hexaploid wheats after chemical desiccation of the plant canopy
(TKW = 1,000-kernel weight).
Genetic diversity of Siberian wheat cultivars.
A set of 54 common spring wheat cultivars grown in the Siberian
region of the Russian Federation was analyzed using 22 wheat microsatellite
markers that determine 23 loci located on 19 different chromosomes.
In total, 151 alleles were detected with an average of 6.6 and
a range of 3-11 alleles/locus. The average PIC value was 0.70.
A wheat microsatellite located on the B genome produced the most
alleles/locus (7.6) compared to those located on the A (6.0) and
D (6.0) genomes. Genetic similarity values between cultivars ranged
from 0.19 to 0.96 and were used to produce a dendrogram. With
a few exceptions, the cultivars clustered in two groups consisting
of old (before 1960) and modern cultivars, indicating the qualitative
shift in the diversity of the spring wheats grown in Siberia during
the last century.
Acknowledgment. E.K. Khlestkina thanks the 'Deutsche Forschungsgemeinschaft'
(Project No. 436RUS17/16/02), the Siberian Branch of Russian Academy
of Science (Lavrentjev award and the 45th Anniversary of SB RAS
Award for Young Scientists), and the Administration of the Novosibirsk
region (special award for young scientists, 2002).
Development of wheatAegilops tauschii
introgression lines. [p.
A set of T. aestivum cultivar Chinese Spring/synthetic,
chromosome-substitution lines was used to create single-chromosome
recombinant lines for the seven D-genome wheat chromosomes by
backcrossing with Chinese Spring. The synthetic wheat used for
the production of the substitution lines was obtained from a cross
of tetraploid emmer with Ae. tauschii and, therefore, the
material produced contains different segments of individual Ae.
tauschii chromosomes in the Chinese Spring background. After
backcrossing with Chinese Spring, 85 defined homozygous T.
aestivum-Ae. tauchii introgression lines were selected
using microsatellite markers. Because Ae. tauschii is known to
represent a valuable source of genes for resistance against biotic
and abiotic stress, the introgression lines produced have a high
potential for revealing and studying profitable genes or QTL in
wild species. The material is available on request.