ITEMS FROM GERMANY

 

INSTITUT FÜR PFLANZENGENETIK UND KULTURPFLANZENFORSCHUNG (IPK)

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 copper tolerance.

 

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).

 Accession  Species  Ploidy level  Growth habit  Origin  TKW (control)  TKW (treatment)  %
 H 1  T. turgidum subsp. turgidum  4x  Winter  Germany  48.04  20.43  42.53
 H 2  T. turgidum subsp. turgidum  4x  Winter  Europe  40.01  28.45  71.11
 H 3  T. turgidum subsp. turgidum  4x  Winter  Germany  38.85  20.41  52.54
 H 4  T. turgidum subsp. turgidum  4x  Winter  Germany  31.40  11.98  38.15
 H 5  T. turgidum subsp. turgidum  4x  Winter  Europe  30.64  23.89  77.97
 H 6  T. turgidum subsp. turgidum  4x  Winter  Italy  42.63  25.50  59.82
 H 7  T. turgidum subsp. turgidum  4x  Winter  Hungary  34.11  16.73  49.05
 A 1  T. turgidum subsp. turgidum  4x  Spring  Spain  30.70  20.12  65.53
 A 2  T. turgidum subsp. durum  4x  Spring  Tunisia  32.66  24.03  73.58
 A 3  T. turgidum subsp. polonicum  4x  Spring  Germany  41.51  32.13  77.40
 A 4  T. turgidum subsp. polonicum  4x  Spring  Germany  50.89  28.32  55.65
 A 5  T. turgidum subsp. turanicum  4x  Spring  Iran  63.04  21.31  33.80
 A 6  T. aestivum subsp. aestivum  6x  Spring  Canada  33.50  13.39  39.97
 A 7  T. aestivum subsp. aestivum  6x  Spring  Australia  30.26  13.57  44.84

 

Genetic diversity of Siberian wheat cultivars. [p. 28]

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. 29]

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.

Publications. [p. 29-30]