GrainGenes

ITEMS FROM THE CZECH REPUBLIC AND FRANCE

RESEARCH INSTITUTE OF CROP PRODUCTION - RICP

Drnovska 507, CZ-161 06 Prague 6 - Ruzyne, Czech Republic.

http://genbank.vurv.cz/ewdb

Evaluation of a spring triticale collection.

Z. Stehno.

The collection of spring triticale was launched in the Czech gene bank in the early 1990s, which means it was relatively early, because up to now no spring triticale has been registered in the Czech Republic. At present, our collection consists of 199 accessions, which are regularly evaluated. The results of field experiments are compared to spring wheat cultivar Sandra, one of the spring wheat varieties registered in the country.

Growth and developmental phases and canopy characteristics are evaluated in 4-m2 plots. Resistance to diseases is evaluated under natural infection (powdery mildew) or under infection pressure in an infection nursery (stem and glume rusts). Evaluation of the most important yield components and grain yield estimation are done after harvest. Analyses of variance is used to test differences among the accessions and years.

Phenological characteristics. During the vegetative periods in 1998 and 1999, numbers of days from the time of seedlings emergence to the beginning of heading, flowering, and wax ripeness were recorded (Table 1). No significant differences among cultivars were found for any of the characters.

The cultivar Chacal was very early for all recorded traits (51.0, 58.5, and 102.5 days, for beginning of heading, flowering, and wax ripeness, respectively). On the other hand, the cultivar Mostral was the latest (57.5, 64.0, and 108.0 days, respectively). The check spring wheat cultivar Sandra had the shortest grain-filling stage and relatively late heading but reached wax ripeness very early. All stages were influenced by growing conditions of the year (significant differences were noted between years).

Plant height and lodging. The plant heights of the triticale cultivars ranged from 74.5 to 91.5 cm. The spring wheat Sandra was the shortest accession (69.0 cm) in the set tested (Table 2). Owing to the influence of different growing (climatic) conditions of the years, differences among the cultivars were not significant.

Suitable plant height provided resistance to lodging that was very good and no scores lower than 8 on a 1-9 scale (9 = canopy without any lodging) were recorded.

Diseases. Resistance to the rusts was tested in the infection nursery by Dr. Bartos' group (Table 3). No significant differences were found in spite of low resistance of the check cultivar Sandra to stem rust. Triticale accessions had good resistance to stem rust, ranging between 6.0 (Mostral) and 8.5 (10 triticale accessions).

Very high resistance was scored in the case of glume rust (8.5 and higher). Only the cultivars Daman, Moloc, and Riegel were not fully resistant.

Response to powdery mildew was tested under normal field conditions. Strong infection pressure was provided by appearance of the disease on check wheat cultivar Sandra and other spring wheat varieties in the same experimental field. Sandra had significantly lower resistant to powdery mildew than all accessions of spring triticale tested in the experiment. The high resistance of spring triticale to powdery mildew is an important advantage.

Yield and 1000-kernel weight. Among yield components, 1,000-kernel weight plays an important role (Table 4). The spring wheat Sandra had the lightest seeds (41.4 g) among tested accessions. The seeds of Mizar were very similar in this character. Thirteen cultivars formed the major group with 1,000-kernel weights between 45 and 50 grams. Tridoc, Mostral, Rigel, Catria, and Passi belonged to the group at 50-54 grams. Kernels of AC Alta were exceptionally large and heavy (58.3 g).

For grain yield, some triticale cultivars (Wanad, AC Alta, Catria, Rigel, and Kissa) were above the check wheat cultivar Sandra ( 5.21 t/ha), but others were less productive.

The effect of varietal purity on the quality of declared varieties of food wheat.

J. Bradová, J. Cerny *, and A. Sasek.
* Czech University of Agriculture, Praha, Czech Republic.

At present, the registration of a variety has become a part of the purchase of wheat. The variety represents a guarantee of hereditary traits and properties, including food and baking quality. Czech-registered varieties of wheat
are divided according to technological properties into quality grades E, A, B, and C. The grade E (elite) represents varieties with very good baking quality. Good, varieties are usable alone designated grade A, and supplementary varieties usable in mixtures are grade B. Grade C includes varieties unsuitable for food purposes (Anonymous 1998).

This study was aimed at determining the effect of admixtures of a supplementary (Siria) variety and a nonfood (Trane) wheat on the quality of a food wheat of the elite grade (Brea). At the same time, the suitability of gliadin and HMW-glutenin electrophoresis for use as a control of varietal registration was investigated. Experimental variants were based on electrophoretic analysis of the varieties Siria, Trane, and Brea and mixtures of Brea with Siria and Trane in different percentage ratios. To separate gliadins and to set gliadin allelic blocks, the published procedures (Sasek and Sykorová 1989) were used. Electrophoresis of HMW-glutenin subunits by SDS-PAGE and setting of allelic glutenin blocks were done according to the described methodologies (Laemmli 1970; Payne at al. 1981). To judge the effects of admixtures on baking quality, a sedimentation value was determined according to Axford and Zeleny. Extensograph values were determined, and baking tests were performed. The data obtained were statistically evaluated using the computer program MS Excel (Table 5). A prerequisite for control of the purity of individual wheat varieties using electrophoresis of protein markers is specific for each registered wheat variety. The sedimentation test indicated that 15 or 20 % of admixtures (either Siria or Trane) decreased the sedimentation value of the control variety Brea. The results of the extensographic assessment (extensographic maximum and extensographic energy) and direct baking trial (specific volume of baking and bulk productivity) confirmed a significant decrease of baking quality after reaching the 20 % limit of admixture of low-quality variety or the mixture of low-quality varieties (Table 5).

References.

• Anonymous. 1998. The National List of Varieties. The Central Institute for Supervising and Testing.
  Laemmli VK. 1970. Cleavage of structural proteins during assembly of the head bacteriophage T4. Nature 227:680-685.
• Payne PI, Holt LM, and Law CM. 1981. Structural and genetical studies of the HMW subunits of wheat glutenin. 1. Allelic variation in subunits amongst varieties of wheat (T. aestivum L.). Theor Appl Genet 60:229-236.
• Sasek A. and Sykorová S. 1989. Standardization of vertical electrophoresis in starch gel columns and characterization of gliadin allelic blocks. Scientia Agric Bohemoslov 21:99-108.