Cultivar Saratovskaya Research Articles

Влияние липополисахаридов грамотрицательных бактерий различных таксономических групп на морфогенетическую активность каллусов мягкой пшеницы

In vitro tissue culture is actively used in modern plant breeding for genetic transformation, effective selection, rapid production and propagation of genetically homogeneous lines. For many crops, the low yield of regenerated plants is limiting for the use of calluses in the breeding process. Some bacterial lipopolysaccharides are able to increase the morphogenetic activity of plant calluses, increasing the efficiency of in vitro technology. In this work, we investigated the effect of lipopolysaccharides (LPS) from the rhizobacterial strains Ensifer adhaerens T1Ks14, Ochrobactrum quorumnocens T1Kr02, and Pseudomonas chlororaphis K3 on the processes of callusogenesis, the formation of morphogenic calluses and regenerant plants of common wheat (Triticum aestivum L.) of a low-morphogenic line with the Rht-B1a dwarfing gene, obtained on the basis of the cultivar Saratovskaya 29. It was found that LPS preparations at a concentration of 10 μg/ml had different effects on wheat tissue cultures. The yield of calluses from explants obtained from immature embryos significantly increased by 2.5% when exposed to LPS of the O. quorumnocens strain T1Kr02 and decreased by 4% in the variant with LPS from P. chlororaphis K3. The yield of morphogenic calluses increased under the influence of LPS from E. adhaerens T1Ks14 (+57%) and P. chlororaphis K3 (+41%). LPS strain O. quorumnocens T1Kr02 had a negative effect on the yield of regenerated plants, while the other two LPS preparations did not differ from the control in this parameter. As a result, the effectiveness of using the LPS preparations from explants to regenerants was significantly higher only in the variant of the E. adhaerens strain T1Ks14 (+64%). The data obtained indicate significant differences in the response of plant tissue cultures to LPS of various rhizosphere bacteria.

Regions of Chromosome 2A of Bread Wheat (Triticum aestivum L.) Associated with Variation in Physiological and Agronomical Traits under Contrasting Water Regimes.

Understanding the genetic architecture of drought tolerance is of great importance for overcoming the negative impact of drought on wheat yield. Earlier, we discovered the critical role of chromosome 2A for the drought-tolerant status of wheat spring cultivar Saratovskaya 29. A set of 92 single-chromosome recombinant double haploid (SCRDH) lines were obtained in the genetic background of Saratovskaya 29. The lines carry fragments of chromosome 2A from the drought-sensitive cultivar Yanetzkis Probat. The SCRDH lines were used to identify regions on chromosome 2A associated with the manifestation of physiological and agronomical traits under distinct water supply, and to identify candidate genes that may be associated with adaptive gene networks in wheat. Genotyping was done with Illumina Infinium 15k wheat array using 590 SNP markers with 146 markers being polymorphic. In four identified regions of chromosome 2A, 53 out of 58 QTLs associated with physiological and agronomic traits under contrasting water supply were mapped. Thirty-nine candidate genes were identified, of which 18 were transcription factors. The region 73.8–78.1 cM included the largest number of QTLs and candidate genes. The variation in SNPs associated with agronomical and physiological traits revealed among the SCRDH lines may provide useful information for drought related marker-assisted breeding.

Drought tolerance evaluation of bread wheat (Triticum aestivum L.) lines with the substitution of the second homoeological group chromosomes

Bread wheat spring cultivar Saratovskaya 29 (S29) is a highly drought tolerant. S29, five single chromosome substitution and two introgression lines of this cultivar for chromosomes of second homoeological group were grown in a climatic chamber under optimal and water deficit conditions of water supply. The donor of the three homologous chromosomes 2A, 2B and 2D was the German spring cultivar Yanetskis Probat; the donors of chromosome 2D were the old spring varieties of Western Siberia, Caesium 111 and Sibirka 1818. The donors of 2A chromosome were the species Triticum timopheevii and Aegilops markgrafii. Eleven physiological indexes including water use efficiency, the chlorophyll a, chlorophyll b and carotenoids contents, osmotic substances contents, antioxidant enzymes activities and lipoxygenase activity were measured in leaves of wheat at the stage of beginning of earing. To assess genotypes, we established a comprehensive evaluation value (D) based on various measured physiological parameters and shoot biomass. The D positively correlated with the tolerance of shoot biomass (r = 0.955, P < 0.001) and was reduced in four of seven lines with a modified genome. The least stable were the line with the introgression from Aegilops markgrafii in 2A chromosome and the line with the substitution of 2D chromosome of the recipient for the homoeologous chromosome from Sibirka 1818. All lines changed the adaptation strategy compared to the recipient variety. The accumulation of a large amount of soluble sugars in the leaves of lines was the largest difference between them and the recipient S29.

Marker-Assisted Development of a Blue-Grained Substitution Line Carrying the Thinopyrum ponticum Chromosome 4Th(4D) in the Spring Bread Wheat Saratovskaya 29 Background

There is growing interest in cereals with anthocyanins in grain as a source of natural biologically active compounds beneficial for human health. In bread wheat, anthocyanins accumulate in the pericarp, under control of Pp genes, and in the aleurone layer, under control of Ba. Breeding anthocyanin-rich wheat cultivars is possible through the transfer of genes from genetic stocks to the desired cultivars. A blue-grained substitution line, s:S294Th(4D) (BC7 progeny), of the bread wheat cultivar Saratovskaya 29 (S29) carrying the Thinopyrum ponticum (Podp.) chromosome 4Th was developed. The 4Th/4D substitution was confirmed with chromosome C-banding and multicolor FISH, as well as by microsatellite analysis. Total anthocyanin content in the bran fraction of the new blue-grained line was 475.7 μg/g compared to 355.6 μg/g of the control purple-grained near-isogenic line, i:S29Pp-A1Pp-D1Pp3P, and a total absence in S29. Although the developed line carries entire chromosome substitution, its 1000 grains weight, milling parameters, and dough physical properties did not differ or decreased slightly comparison to S29. These results support that the developed substitution line can be of interest in breeding programs to increase the anthocyanin production in commercial varieties.

Identifikacija gena za otpornost na lisnu rđu u jarom oplemenjivačkom materijalu hlebne pšenice u Poljoprivrednom istraživačkom institutu za jugoistočne oblasti u Rusiji

Leaf rust caused by Puccinia triticina is a common bread wheat disease in the Volga Region of Russia and breeding for this disease resistance is a priority for the Agricultural Research Institute for South-East Regions wheat program. Knowledge of the effective resistance genes present in the germplasm is relevant when selecting for effective and more durable resistance. P. triticina races with virulence to Lr9, Lr19, Lr26 and with other different virulence combinations and molecular markers of L r genes were used to determine which seedling resistance genes might be present in the 68 bread wheat lines and cultivars. Studies have shown that the effective protection against leaf rust widespread in the Volga Region spring bread wheat cultivars is controlled by Lr6Ag and Lr6Agi+Lr19 genes. In addition, cultivars carry Lr10, Lr19, Lr10+Lr26 genes. It was found that in the studied set of lines the leaf rust resistance is determined by the following Lr-genes and its combinations: 9, 10, 19, 26, 34, 37, 41, Satu, 6Ag. Moreover, usage frequency of Lr19 is 89.5%, Lr10 -40.4%, Lr26 -31.6%, Lr6Ag -21%, Lr28 -3.5%, Lr41 -3.5%, Lr9 - 1.8%, Lr34 -1.8%, Lr37 -1.8%, LrSatu -1.8%. The frequency of two L r-genes combinations is 45.7%, three - 21% and four Lr-genes - 5.3%. Mainly are used such Lr-genes combinations as: Lr19+Lr26 and Lr10+Lr19+Lr26 - 22.8%; Lr19+Lr6Ag -7%. The four Lr-genes combinations has been included Lr10+Lr26+Lr28?+Lr6Ag -1.8%, Lr1+Lr10+Lr26+Lr6Ag -1.8% and Lr10+Lr19+Lr28?+Lr6Ag -1.8%. In addition, the effective Lr19 with nonidentified Lr-genes from cultivar Saratovskaya 57 (L164) and a. elongatum (CI-7-57) combinations has been identified.

Chromosomal Location and Mapping of Quantitative Trait Locus Determining Technological Parameters of Grain and Flour in Strong-flour Bread Wheat Cultivar Saratovskaya 29

Bread wheat is the primary bread crop in the majority of countries in the world. The most important product that is manufactured from its grain and flour is yeast bread. In order to obtain an excellent bread, grain with high physical properties is needed for flour and dough. The Russian spring wheat cultivar Saratovskaya 29 is characterized by its exclusively high physical properties of flour and dough. The purpose of this work was to identify the chromosomes carrying the main loci for these traits in Saratovskaya 29 and to map them using recombinant substitution lines genotyped with molecular markers. A set of inter-varietal substitution lines Saratovskaya 29 (Yanetzkis Probat) was used to identify the “critical” chromosomes. The donor of individual chromosomes is a spring cultivar with average dough strength and tenacity. Substitution of 1D and 4D*7A chromosomes in the genetic background of Saratovskaya 29 resulted in a significant decrease in the physical properties of the dough. Such a deterioration in the case of 1D chromosome might be related to the variability of gluten protein composition. With the help of recombinant substitution double haploid lines obtained from a Saratovskaya 29 (Yanetzkis Probat 4D*7A) substitution line the region on the 4D chromosome was revealed in the strong-flour cultivar Saratovskaya 29, with the microsatellite locus Xgwm0165 to be associated with the unique physical properties of flour and dough. The detected locus is not related to the composition gluten proteins. These locus may be recommended to breeders for the selection of strong-flour cultivars. Additionally, a QTL associated with vitreousness of grain was mapped in the short arm of chromosome 7A.

Effects of limited introgressions from Triticum timopheevii Tausch. into the genome of bread wheat (Triticum aestivum L.) on physiological and biochemical traits under normal watering and drought

Alien hybridization in cereals is used for the comparative investigation of the genome structure and evolution, as well as for extracting useful genes from the wild gene pool. The tetraploid species Triticum timopheevii has long been used as a source of genes for resistance to fungal diseases. Line 821 was developed on the genetic background of cultivar Saratovskaya 29 (S29), which is drought-resistant but is very susceptible to diseases and carries large introgressions in 2A and 2B chromosomes and a small introgression in the subtelomeric region of the 5A chromosome. The two genotypes were compared for the parameters associated with the direct and indirect reaction of the photosynthetic apparatus to water stress. In the flag leaves of line 821, an increased transpiration rate and stomatal conductance (1.6 times the value in optimal watering and 1.2 times the value under a water deficit) and, correspondingly, reduced efficiency of water usage were found compared to the initial cultivar. Additionally, the actual effectiveness and electron transport rate of photosystem II, the chlorophyll and carotenoid content, and the total antioxidant capacity were reduced by approximately a factor of three under water stress. Under the same conditions, the activity of lipoxygenase doubled. On the whole, tolerance to a water deficit declined in the line in comparison to the parent cultivar and was accompanied by leaf senescence. Thus, it may be supposed that 2A, 2B, and 5A chromosomes of the drought-tolerant cultivar S29 carry important genetic factors responsible for the reaction to water stress in wheat plants.

Marker-assisted development and characterization of a set of Triticum aestivum lines carrying different introgressions from the T. timopheevii genome

A set of common wheat introgression lines carrying one or two introgressions from Triticum timopheevii was produced by means of marker-assisted backcross selection. The starting material consisted of two BC1F20 (T. aestivum*2/T. timopheevii) lines with resistance to leaf rust, stem rust, powdery mildew, spot blotch, and loose smut and containing multiple 1At, 2At, 2G, 3AtL, 3GL, 4GL, 5AtL, 5GL, and 6G T. timopheevii chromosome fragments. The two lines were crossed with, and backcrossed three times to common wheat cultivar Saratovskaya 29. In total, 275 BC2F1 and BC3F2 plants were characterized by microsatellite markers and in situ hybridization. Molecular and cytological analyses revealed 38 plants with a single introgression from chromosomes 2G, 5GL, or 6G of T. timopheevii and 72 plants, each with two introgressions, among them three plants carrying a T. timopheevii translocation involving the D genome (2DS.2GL). It was observed that the lengths of fragments introgressed from the At genome were more than halved in the BC2 generation, while the lengths of 2G and 5GL introgressed fragments were only slightly reduced after the third backcross. The introgression lines were tested for resistance to the native Puccinia triticina population of the Western Siberian region of Russia. Lines with a single introgressed 5GL region carrying the major leaf rust resistance locus, QLr.icg-5B, were completely resistant. The presence of two minor resistance loci, QLr.icg-2A and QLr.icg-1A, suppressed disease development and reduced the number of urediniospores by up to 25 % but did not lead to a hypersensitive response. The introgression lines therefore constitute promising sources of new resistance to Puccinia triticina.

A cytogenetic study of the blue-grain line of the common wheat cultivar Saratovskaya 29

The chromosome composition of the blue-grain line i:S29Ba of the cultivar Saratovskaya 29 was identified by cytological, GISH, and microsatellite analyses and C-banding. It was found that common wheat chromosome 4B of the cultivar Saratovskaya 29 was substituted with the Agropyron elongatum Host. chromosome carrying the gene for blue grain (s:S294Ag(4B)) during the construction of this nearly isogenic line. The blue-grain line was tested for productivity. The substitution of total chromosome 4B of the cultivar Saratovskaya 29 by Ag. elongatum chromosome 4 did not significantly affect the spike productivity parameters and grain quality with the exception of spike length (plus effect), spike density, and vitreousness (minus effects). The blue-grain line with s:S294Ag(4B) can be used in further studies associated with chromosome engineering in cereals and wheat breeding.

Morphological characterization and inheritance of leaf hairiness in wheat (Triticum aestivum L.) as analyzed by computer-aided phenotyping

Computer-aided image processing was used to study the morphology of leaf hairiness in the wheat cultivars Saratovskaya 29 and Golubka, as well as the introgressed line 102/00i of the cultivar Rodina carrying the gene for leaf hairiness introgressed from Aegilops speltoides. Morphological differences in leaf hairiness were detected and described in detail. The genetic control of hairiness was studied in two cultivars (Golubka and Saratovskaya 29) with similar hairiness patterns. Crossing these cultivars with the cultivar Rodina showed a monogenic inheritance in the cultivar Golubka and a digenic inheritance in the cultivar Saratovskaya 29, which has a denser hairiness. In the line 102/00i and the cultivar Golubka, the number of trichomes was positively correlated with their mean length. The cultivar Golubka was used as an example to study the effect of environmental conditions on the formation of hairiness. Plants of this cultivar were found to form more but shorter trichomes under field conditions.

The role of chromosomes from homeologous group 5 in regulation of grain hardness and protein content in substitution lines of common wheat cultivar Saratovskaya 29

Genetic regulation of grain hardness and protein content in intervarietal substitution lines for chromosomes of homeologous group 5 was examined. Common wheat cultivar Saratovskaya 29 with high bread-backing properties served as the recipient. Donors of chromosomes 5A and 5D were 18 cultivars with variable traits examined, including high-protein cultivars (Atlas 66 and Diamant 2), and soft-grain cultivars (Ul'yanovka and Chinese Spring). Analysis of substitution lines pointed to a substantial effect of chromosome 5D on the regulation of both traits. It was demonstrated that as a result of intervarietal substitution for chromosome 5D from donor cultivars Ul'yanovka and Chinese Spring, the endosperm softness was increased compared to the recipient cultivar Saratovskaya 29. Substitution lines Saratovskaya 29/Atlas 66 5D and Saratovskaya 29/Diamant 2 5D were characterized by high grain protein content, as well as by high endosperm softness. In addition, the line Saratovskaya 29/Novosibirskaya 67 5D, characterized by grain hardness higher than in Saratovskaya 29, was isolated. In the lines with intervarietal substitution of chromosome 5A, grain protein content was found to be lower than in recipient cultivar Saratovskaya 29.

Analysis of spike productivity traits in near-isogenic lines of the common wheat cultivar Saratovskaya 29 carrying alien marker genes

Six near-isogenic lines of the wheat cultivar Saratovskaya 29 carrying five marker genes from different species (Triticum compactum L., T. polonicum L., T. petropavlovskyi Udacz. et Migusch., Aegilops elongatum Host. and Secale cereale L.) were studied. It was shown that the introduced marker genes of taxonomic significance, C and P, have strong pleiotropic effects on quantitative traits of the spike productivity.

Production of alloplasmic and euplasmic wheat-barley ditelosomic substitution lines 7H1Lmar(7D) and analysis of the 18S/5S mitochondrial repeat in these lines

Alloplasmic lines of common wheat with disomic substitution of chromosome 7D for telocentric chromosome 7H(1)Lmar of barley H. marinum subsp. gussoneanum Hudson were isolated from the plants of generation BC3, produced as a result of backcrossing of barley-wheat hybrids H. marinum subsp. gussoneanum (2n = 28) x x T. aestivum (2n = 42), Pyrotrix, cultivar, with 28 common wheat cultivars Pyrotrix 28 and Novosibirskaya 67. Chromosome substitution pattern was determined using SSR analysis and C-banding. In preliminary genomic in situ hybridization experiments, telocentric chromosomes were assigned to wild barley was established. In the BC3F8-generations of three alloplasmic lines with the 7H(1)Lmar(7D) substitution type the differences in fertility manifestation were observed: most of the L-32(1) plants were sterile, in line L-32(2) only sporadic plants were sterile, and line L-32(3) was fertile. Simultaneously with these experiments, using self-pollinated progeny of the hybrids obtained in crosses of common wheat cultivar Saratovskaya 29 (2n = 41), monosomic for chromosome 7D, with common wheat cultivar Pyrotrix 28 with addition of pair of telocentric chromosomes 7H(1)Lmar(7D) of barley H. marinum subsp. gussoneanum, euplasmic wheat-barley ditelosomic substitution 7H(1)Lmar(7D) lines were isolated. The lines obtained had normal fertility. PCR analysis of the 18S/5S mitochondrial repeat (hereafter, mtDNA sequence) in alloplasmic and euplasmic ditelosomic substitution lines 7H(1)Lmar(7D) was performed. In the plants from alloplasmic sterile line L-32(1), the sequences only of the barley (maternal) type were revealed, while the plants from alloplasmic fertile lines L-32(2) and L-32(3) demonstrated heteroplasmy (the presence of barley- and wheat-like sequences within one individual). In euplasmic ditelosomic substitution lines the presence of only wheat-like 18S/5S mitochondrial repeat sequences was observed. The results indicate that the presence of barley-like mtDNA sequences in alloplasmic substitution lines was not associated with the presence of barley chromosomes in their nuclear genomes.

Features of the regulation of meiotic restitution in androgenic haploids of wheat-rye substitution lines 2R(2D)1, 2R(2D)3, and 6R(6A) (Triticum aestivum L., cultivar Saratovskaya 29/Secale cereale L., cultivar Onokhoiskaya)

Regulation of meiotic restitution in androgenic haploids generated by cultivation of isolated pollinators of three wheat-rye substitution lines 2R(2D)1, 2R(2D)3, and 6R(6A) (Triticum aestivum L., cultivar Saratovskaya 29/Secale cereale L., cultivar Onokhoiskaya) was studied. The presence of rye chromosomes and the absence of homeologous wheat chromosomes in the haploid plant genome was shown to cause meiotic restitution, as observed in the case of androgenic haploids 6R(6A), or to inhibit in--in meiosis of haploids 2R(2D)1 and 2R(2D)3. In haploids of lines 2R(2D)1 and 2R(2D)3, the reductional type of division of univalent chromosomes was observed, leading to preferential formation of tetrads. In haploids of line 6R(6A), the equational type of division of univalents into sister chromatids, resulting in the block of the second division and formation of diads in approximately 50% of cells, was detected. These results confirm data on the effect of the genotype of line 2R(2D)1 on the induction of reductional type division of univalents and two-phase meiosis, which were earlier obtained in studies of meiosis in polyhaploids 2R(2D)1 x S. cereale L., cultivar Onokhoiskaya.

Effect of rye Secale cereale L. chromosomes 1R and 3R on polyembryony expression in hybrid combinations between (Hordeum L.)-Triticum aestivum L. alloplasmic recombinant lines and wheat-rye substitution lines T. aestivum L.-S. cereale L.

The effect of rye chromosomes on polyembryony was studied for reciprocal hybrid combinations between (Hordeum vulgare L.)-Triticum aestivum L. alloplasmic recombinant lines and five wheat T. aestivum L. (cultivar Saratovskaya 29)-rye Secale cereale L. (cultivar Onokhosikaya) substitution lines: 1R(1D), 2R(2D), 3R(3B), 5R(5A), and 6R(6A), and for direct hybrid combinations between the [H. marinum ssp. gussoneanum (H. geniculatum All.)]-T. aestivum alloplasmic recombinant line and the wheat-rye substitution lines 1R(1A), 1R(1D), and 3R(3B). Chromosomes 1R and 3R of rye cultivar Onokhoiskaya proved to affect the expression of polyembryony in the hybrid combinations that involved the alloplasmic recombinant lines of common wheat as maternal genotypes. Based on this finding, polyembryony was regarded as a phenotypic expression of nuclear-cytoplasmic interactions where an important role is played by rye chromosomes 1R and 3R and the H. vulgare cytoplasm. Consideration is given to the association between the effect of rye chromosomes 1R and 3R on polyembryony in the [(Hordeum)-T. aestivum × wheat-rye substitution lines] hybrid combinations and their stimulating effect on the development on androgenic embryoids in isolated anther cultures of the wheat-rye substitution lines.

The effect of intercultivar substitution of wheat Triticum aestivum L. chromosomes on lipoxygenase activity and its correlation with the technological properties of flour

The effects of intercultivar substitution of individual chromosome pairs (except for 1B, 6D, and 7A) in the wheat cultivars Saratovskaya 29 and Janetzkis Probat, differing in quality, on specific lipoxygenase activity, the grain yield per spike, and the main technological properties of flour and dough were studied. It was demonstrated that the substitution of individual chromosomes of the recipient cultivar Saratovskaya 29 with the homologous chromosomes of the donor cultivar Janetzkis Probat caused significant changes in lipoxygenase activity and several other quality characteristics. The correlations between the lipoxygenase activity and the parameters of physical dough properties were determined. Three molecular forms of lipoxygenase (Lpx-1, Lpx-2, and Lpx-3), differing in the value of surface charge and enzymatic activity, were detected by native PAGE.

Transmission of 5R Chromosomes via Gametes and Its Influence on Spring Bread Wheat Somatic Embryoidogenesis in Vitro

Transmission of chromosomes 5R and 5A via gametes and its effect on somatic embryoidogenesis have been studied with the use of the model 5R(5A) substitution line L2837 = L503/Secale cereale L., cultivar Saratovskaya 5/L503, where L503 is a cultivar of spring bread wheat. It has been found that the frequencies of transmission of univalent chromosomes 5R and 5A determined in experiments on F1 reciprocal hybrids with cultivar Saratovskaya 29 do not reflect their frequencies in the self-pollinated offspring of F1 hybrids; the frequency of transmission of chromosomes 5R and 5A depends on the genotypes of both the recipient cultivar and the donor rye cultivar; and the 5R(5A) substitution in cultivar L503 significantly increases the parameters of somatic embryoidogenesis in vitro in explants from inflorescences.

Features of Crossability, Haploidy and Polyembryony in Hybrid Combinations between Cultivated Barley Hordeum vulgare L. (2n = 14) and Wheat-Rye Substitution Lines Triticum aestivum L., Cultivar Saratovskaya 29/Secale cereale L., Cultivar Onokhoiskaya

The role of individual chromosomes of rye in the manifestation of crossability and seedling development in hybrid combinations between common barley Hordeum vulgare L., cultivar Nepolegayushchii (2n = 14) and five wheat-rye substitution lines Triticum aestivum L., cultivar Saratovskaya 29/Secale cereale L., cultivar Onokhoiskaya (2n = 40 wheat + 2 rye chromosomes). Crossability, which was measured by two parameters--frequency of set grains and frequency of grains with embryos--was shown to be significantly affected by each of the five rye chromosomes examined: 1R, 2R, 3R, 5R, and 6R; the development of barley haploids was affected by rye chromosomes 1 R, 3R, and 5R. We were the first to demonstrate that polyembryony could be induced by mutual effects of barley cytoplasm and rye chromosome 1R. Possible mechanisms controlling the development of haploids and twins in hybrid combinations H. vulgare x T. aestivum/S. cereale are discussed. The conclusion is drawn that hybrid combinations between common barley and wheat-rye substitution lines can serve as new models for studying incompatibility mechanisms in distant crosses and genetic control of parthenogenesis.

Two-Dimensional Mapping of Gliadins Using Biotypes and Null Mutants of Common Wheat Cultivar Saratovskaya 29

Four biotypes differing at the GIi-A I and Gli-A2 loci coding for gliadins, and various “null” mutants at these loci in the common wheat cv Saratovskaya 29, were studied by two-dimensional electrophoresis A-PAGE x SDS-PAGE. Foiir to ten gliadin polypeptides were found to be controlled by each Gli locus. Two different alleles at the Gli-Dl locus, which could not he distinguished in one-dimensional gels, were observed after A-PAGE x SDS-PAGE. Some polypeptides in the two-dimensional map could not be attributed to any Gli-I or Gli-2 locus. The possibility that these polypeptides are the product of additional, gliadin-encoding genes is discussed.

Construction of Immune Lines with Complex Resistance to Leaf Rust and Powdery Mildew in Common Spring Wheat Cultivar Saratovskaya 29

Immune lines resistant both to leaf rust and to powdery mildew were constructed on the basis of common wheat cultivar Saratovskaya 29. Synthetic wheat Triticum timopheevii/Aegilops squarrosa (AAGGDD, 2n = 42) of Savov (Bulgaria) was used as a source of resistance genes. Using cytological analysis of BC2, we selected resistant plants (21") free from meiosis 1 (M1) defects. With these plants and continuous selection, BC8-BC9 immune lines were obtained. The lines were shown to carry new resistance genes differing from the known ones, and were proposed as donors of immunity to the diseases.