Effective resistance to powdery mildew in Aegilops L. accessions

Background. Powdery mildew (Blumeria graminis (DC.) E.O. Speer f. sp. tritici Em. Marchal) is widespread and harmful in all regions of bread wheat cultivation. Severe development of powdery mildew leads to a decrease in the number and weight of grains. Growing resistant cultivars is the most environmentally friendly and economically profitable method to protect wheat from the disease. Development of such cultivars requires a search for new donors of effective genes controlling the resistance. To expand the genetic diversity of wheat for resistance to B. graminis, wild relatives of Triticum aestivum L., including Aegilops L. spp., are widely used. The aim of this work was to characterize seven Aegilops spp. for effective seedling and adult plant resistance to powdery mildew.Materials and methods. The material of the study consisted of 437 accessions representing 7 Aegilops spp. (Ae. speltoides Tausch, Ae. caudata L., Ae. biuncialis Vis., Ae. tauschii Coss., Ae. cylindrica Host, Ae. crassa Boiss. and Ae. ventricosa Tausch) from the collection of the N.I. Vavilov All-Russian Institute of Plant Genetic Resources (VIR, St. Petersburg). Juvenile resistance was studied when the seedlings were inoculated with the agent of powdery mildew under controlled laboratory conditions; the adult plant resistance, after artificial inoculation of the plants and under natural infection in the fields of Pushkin and Pavlovsk Laboratories of VIR. Complex populations of the B. graminis agent were used for inoculation. The types of response to infection were scored 10 days after inoculation according to a conventional scale.Results and conclusions. As a result of the tests, susceptibility to powdery mildew was shown in all Aegilops accessions of the D-genome group; all the studied representatives of Ae. speltoides, Ae. caudata and Ae. biuncialis were highly resistant to powdery mildew

COLLECTIONS OF THE WORLD’S CROP GENETIC RESOURCES FOR THE DEVELOPMENT OF PRIORITY PLANT BREEDING TRENDS

Baking properties of flour made from triticale grain were studied employing the improved triticale lines L-30 and MH Alamo bred at the Leningrad Research Institute of Agriculture "Belogorka" and the cultivars ‘Quasar’ and ‘Mamuchar’ with a predominance of rye and wheat genotypes developed at the North Caucasian Federal Agricultural Research Center. Grain, flour of single-grade grinding, and test baking products were compared using two methods. Laboratory baking was carried out according to the standard method GOST 27669-88 for wheat flour and by the method of St. Petersburg Branch of the Baking Industry Research Institute with the leaven developed for rye flour. The method of test baking with leaven is preferred for evaluation of triticale with weak gluten

Metabolomic approach to search for fungal resistant forms of <i>Aegilops tauschii</i> Coss. from the VIR collection

Broadening of the genetic diversity of donors of resistance to biotic environmental factors is a challenging problem concerning Triticum L., which can be solved by using wild relatives of wheat, in particular, Aegilops tauschii Coss., in breeding programs. This species, believed to be the donor of D genome of common wheat (T. aestivum L.), is a source of some traits important for breeding. This greatly facilitates the possibility of crossing Ae. tauschii with common wheat. Aegilops L. species are donors of effective genes for resistance to fungal diseases in wheat. For instance, genes that determine resistance to rust agents in common wheat were successfully introgressed from Ae. tauschii into the genome of T. aestivum L. The aim of our study was to identify differences in metabolomic profiles of Ae. tauschii forms (genotypes), resistant or susceptible to such fungal pathogens as Puccinia triticina f. sp. tritici and Erysiphegraminis f. sp. tritici.These indicators may be used as biochemical markers of resistance. A comparative analysis of groups of Ae. tauschii accessions showed that metabolomic profiles of the forms with or without resistance to fungal pathogens differed significantly in the contents of nonproteinogenic amino acids, polyols, phytosterols, acylglycerols, mono- and oligosaccharides, glycosides, phenolic compounds (hydroquinone, kempferol), etc. This fact was consistent with the previously obtained data on the relationship between Fusarium resistance in oats (Avenasativa L.) and certain components of the metabolomic profile, such as acylglycerols, nonproteinogenic amino acids, galactinol, etc. Thus, our studies once again confirmed the possibility and effectiveness of the use of metabolomic analysis for screening the genetic diversity of accessions in the VIR collection, of Ae. tauschii in particular, in order to identify forms with a set of compounds in their metabolomic profile, which characterize them as resistant. Ae. tauschii accessions with a high content of pipecolic acids, acylglycerols, galactinol, stigmasterol, glycerol, azelaic and pyrogallic acids, campesterol, hydroquinone, etc., can be used for creating wheat and triticale cultivars with high resistance to fungal pathogens causing powdery mildew, brown rust, and yellow rust

Sources of economically valuable traits for winter triticale breeding in the northwest of the Russian Federation

Background. As a crop, triticale is an important source that can be used to meet the growing needs of animal husbandry in high-quality feeds and of the population in organic products. Triticale combines the high productivity potential of wheat with high adaptability of rye. However, the expansion of triticale production in the Northwestern Region of the Russian Federation is hindered by the unresolved breeding and genetic problems, like tendency to lodging, sprouting in the ear, unstable productivity and insufficient disease resistance. In this regard, the further development of breeding in the Russian Northwest depends on studying the triticale gene pool and synthesis of original initial material for the creation of new high-yielding varieties.Material and methods. Field and laboratory studies were conducted at the experimental base of the "BELOGORKA" Leningrad Research Institute. The experimental design and statistical data processing followed the standard technique. Phenological observations, field and laboratory assessments were carried out according to the standard methods.Results and conclusion. The three-year study (2015-2017) of the winter triticale collection material of different ecogeographic origin has resulted in the identification of genetic sources of individual important agronomic traits, such as early maturity (e.g., 'Don' (k-3637), 'Almaz' (k -3908), 'Proryv' (k-3763), 'Interes' (k-3968), 'Pshenichnoe' (k-3965), 'ADM-6' (k -3544), 'ADM-9' (k-3421), 'Utro' (k-3926)), dwarfness (e.g., 'Ramzaj' (k-4071), 'Samurai' (k-4072), 'Skif' (k-3931), 'Zavet' (k-4020), 'Proryv' (k-3763), 'Dozor' (k-4021), 'Knyaz'' (k-4076),    'L-372'    (k-2806), 'Pshenichnoe' (k-3965), 'Kroha' (k-3929)), productivity (e.g., 'Impul's' (k- 3999), 'Prometey' (k-3900), 'Kvazar' (k-3938), 'Interes' (k-3968), 'Trizub' (k-3969), 'Papsuevskaya' (k-3924), 'Svityaz'' (k-3963), 'Topaz' (k-3909), 'Dawitol' (k-4002), 'Prado' (k-3865)), and disease resistance (e.g., 'PRAG 536' (k-3945), 'PRAG 456' (k-3946), 'Kvazar' (k-3938), 'Prometey' (k- 3900), 'Svyatozar' (k-3940), 'Yasha' (k-3912)). The accessions with a set of important traits that have been selected as the initial material for breeding winter triticale in the Northwest of the Russian Federation include 'Topaz' (k-3909), 'Don' (k-3637) 'Trizub' (k-3969), 'Interes' (k- 3968), 'Pshenichnoe' (k-3965), 'Svityaz'' (k-3963), 'Amulet' (k- 3956), 'Impul's' (k-3999), 'Kvazar' (k-3938), and 'Dawitol' (k-4002). The lines [(Niklap x Antei) x L-21620] x Fidelio and (Niklap x Antei) x ADM-9 have been identified as two promising lines with a complex of economically valuable traits

Juvenile resistance to diseases in Aegilops tauschii Coss. samples

Seedling (juvenile) resistance to 4 diseases was studied in 452 Ae. tauschii samples from VIR World Collection. Eight accessions were highly resistant to leaf rust and they likely have gene for resistance Lr41. Rust from their naturally infected leaves was nonpathogenic on 25 wheat varieties that evidently indicates to the existence of the causal agent of leaf rust specialized to Ae. tauschii . Two samples possess high resistance to dark-brown leaf spot blotch; level of resistance was not changed after 9 continuous subcultivation of artificial B. sorokiniana population on leaves. Six samples were classified as resistant after inoculation with mixture of 7 Stagonospora nodorum isolates, but as susceptible to single isolate of the pathogen. All samples were susceptible to common root rot. Usefulness of selected Ae. tauschii samples for introgression hybridization to transfer juvenile resistance into bread wheat is discussed

Chromosome and Molecular Analyses Reveal Significant Karyotype Diversity and Provide New Evidence on the Origin of Aegilops columnaris

Aegilops columnaris Zhuk. is tetraploid grass species (2n = 4x = 28, UcUcXcXc) closely related to Ae. neglecta and growing in Western Asia and a western part of the Fertile Crescent. Genetic diversity of Ae. columnaris was assessed using C-banding, FISH, nuclear and chloroplast (cp) DNA analyses, and gliadin electrophoresis. Cytogenetically Ae. columnaris was subdivided into two groups, C-I and C-II, showing different karyotype structure, C-banding, and FISH patterns. C-I group was more similar to Ae. neglecta. All types of markers revealed significant heterogeneity in C-II group, although group C-I was also polymorphic. Two chromosomal groups were consistent with plastogroups identified in a current study based on sequencing of three chloroplast intergenic spacer regions. The similarity of group C-I of Ae. columnaris with Ae. neglecta and their distinctness from C-II indicate that divergence of the C-I group was associated with minor genome modifications. Group C-II could emerge from C-I relatively recently, probably due to introgression from another Aegilops species followed by a reorganization of the parental genomes. Most C-II accessions were collected from a very narrow geographic region, and they might originate from a common ancestor. We suggest that the C-II group is at the initial stage of species divergence and undergoing an extensive speciation process

Allele mining of TaGRF-2D gene 5'-UTR in Triticum aestivum and Aegilops tauschii genotypes.

The low diversity of the D-subgenome of bread wheat requires the involvement of new alleles for breeding. In grasses, the allelic state of Growth Regulating Factor (GRF) gene is correlated with nitrogen uptake. In this study, we characterized the sequence of TaGRF-2D and assessed its diversity in bread wheat and goatgrass Aegilops tauschii (genome DD). In silico analysis was performed for reference sequence searching, primer pairs design and sequence assembly. The gene sequence was obtained using Illumina and Sanger sequencing. The complete sequences of TaGRF-2D were obtained for 18 varieties of wheat. The polymorphism in the presence/absence of two GCAGCC repeats in 5' UTR was revealed and the GRF-2D-SSR marker was developed. Our results showed that the alleles 5' UTR-250 and 5' UTR-238 were present in wheat varieties, 5' UTR-250 was presented in the majority of wheat varieties. In Ae. tauschii ssp. strangulata (likely donor of the D-subgenome of polyploid wheat), most accessions carried the 5' UTR-250 allele, whilst most Ae. tauschii ssp. tauschii have 5' UTR-244. The developed GRF-2D-SSR marker can be used to study the genetic diversity of wheat and Ae. tauschii