Wild grasses as the reservoirs of infection of rust species for winter soft wheat in the Northern Caucasus.

Common winter wheat is the main grain crop cultivated in the North Caucasus. Rust disease damage is one of the factors limiting wheat productivity. There are three species of rust in the region: leaf (Puccinia triticina), stem (P. graminis) and stripe rust (P. striiformis), and their signif icance varies from year to year. The most common is leaf rust, but in the last decade the frequency of its epiphytotic development has signif icantly decreased. At the same time, an increase in the harmfulness of stripe rust (P. striiformis) is noted. Stem rust in the region is mainly absent or observed at the end of the wheat growing season to a weak degree. Only in some years with favorable weather conditions its mass development is noted on susceptible cultivars. It is believed that the sources of infection with rust species in the North Caucasus are infested soft wheat crops, wild-growing cereals and exodemic infection carried by air currents from adjacent territories. In the North Caucasus, forage and wild grasses are affected by Puccinia species almost every year. Depending on weather conditions, the symptom expression is noted from late September to December and then from late February to May-June. Potentially, an autumn infection on grasses can serve as a source for infection of winter soft wheat cultivars sown in October. The purpose of these studies is to characterize the virulence of P. triticina, P. graminis, P. striiformis on wild cereals and to assess the specialization of causative agents to winter wheat in the North Caucasus. Infectious material represented by leaves with urediniopustules of leaf, stem and stripe rusts was collected from wild cereals (Poa spp., Bromus spp.) in the Krasnodar Territory in October-November 2019. Uredinium material from P. triticina, P. striiformis, and P. graminis was propagated and cloned. Monopustular Puccinia spp. isolates were used for virulence genetics analysis. In experiments to study the specialization of rust species from wild-growing cereals on common wheat, 12 winter cultivars were used (Grom, Tanya, Yuka, Tabor, Bezostaya 100, Yubileynaya 100, Vekha, Vassa, Alekseich, Stan, Gurt, Bagrat). These cultivars are widely cultivated in the North Caucasus region and are characterized by varying degrees of resistance to rust. Additionally, wheat material was inoculated with Krasnodar populations of P. triticina, P. striiformis, P. graminis from common wheat. In the virulence analysis of P. triticina on cereal grasses, four phenotypes (races) were identif ied: MCTKH (30 %), TCTTR (30 %), TNTTR (25 %), MHTKH (15 %), and f ive were identif ied in P. graminis (RKMTF (60 %), TKTTF, RKLTF, QKLTF, LHLPF (10 % each). Among P. striiformis isolates, three phenotypes were identif ied using the International and European sets of differentiating cultivars - 111E231 (88 %), 111E247 (6 %) and 78E199 (6 %). Using isogenic Avocet lines, 3 races were also identif ied, which differed among themselves in virulence to the Yr1, Yr11, Yr18 genes (with the prevalence of virulent ones (94 %)). Composite urediniums' samples (a mixture of all identif ied races) of grass rust of each species were used to inoculate winter wheat cultivars. The most common winter wheat cultivars (75 %) were characterized by a resistant response when infected with P. graminis populations from common wheat and cereal grasses. All these cultivars were developed using donors of the rye translocation 1BL.1RS, in which the Lr26, Sr31, and Yr9 genes are localized. The number of winter wheat cultivars resistant to leaf rust in the seedling phase was lower (58 %). At the same time, all the studied cultivars in the seedling phase were susceptible to P. striiformis to varying degrees. The virulence analysis of the leaf, stem and stripe rust populations did not reveal signif icant differences in the virulence of the pathogens between wild-growing cereals and soft wheat. Urediniomaterial of all studied rust species successfully infested soft wheat cultivars. The results obtained indicate that grasses are rust infection reservoirs for common wheat crops in the North Caucasus.

[Genetic diversity of common wheat varieties at the gliadin-coding loci].

One hundred and fifty Russian and foreign winter common wheat varieties were examined by the PAGE method. A total of 70 alleles were identified at seven gliadin-coding loci. It was demonstrated that 42% of varieties were heterogeneous, i.e., were represented by a number of genotypes, while 52% of varieties were homogeneous. A unique combination of gliadin alleles was typical of 91.3% of examined varieties, while 8.7% of varieties had identical alleles of all gliadin-coding loci and were indistinguishable. Frequent and rare alleles were identified, with the former accounting for 18.6% of all alleles. It was demonstrated that allelic diversity at the Gli-2 loci (47 alleles) was almost twice that at the Gli-1 loci (23 loci) and was determined by the number of rare alleles. New alleles for the winter common wheat, including three alleles of the GliA2 locus and two alleles of the Gli-B2 locus, were determined. A tendency toward a reduction of the genetic diversity level in modern varieties, which was due to the use of identical parental varieties in breeding programs, was identified.

[Identity of the Rht-11 and Rht-B1e reduced plant height genes].

The Rht (reduced plant height) genes provided a basis for the "green revolution", which led to a substantial increase in wheat productivity. More than 20 Rht genes are now known in wheat, Rht-B1 and Rht-11 being among the most important ones. Analysis of a segregating F2 population and molecular analysis of the common wheat cultivars carrying the Rht-11 gene showed that the Rht-11 and Rht-B1e genes are identical.

[A comparison of two existing catalogues of the alleles of gliadin-coding loci in winter common wheat].

Two catalogs of alleles of gliadin-coding loci, controlling synthesis of a storage protein of wheat caryopsis, gliadin, were compared. One catalogue comprises the alleles detected according to the electrophoretic patterns in starch gels; the other, in polyacrylamide gels. Determination of the allelic state of gliadin-coding loci in 31 previously not studied cultivars of winter common wheat allowed us to construct a matching system for the alleles compiled in the two catalogs, which gives the possibility to compare the results of wheat cultivar analyses performed at different scientific institutions.

[Features of lipogenesis of basidiomycetes Pleurotus ostreatus and Flammulina velutipes in cultures on various media]. / Osobennosti lipogeneza bazidiomitsetov Pleurotus ostreatus i Flammulina velutipes pri kul'tivirovanii na razlichnykh sredakh.

The compositions of free fatty acids (FA) in the mycelia of oyster cap (Pleurotus ostreatus (Jacq. ex Fr.) Kumm.) and honey mushroom (Flammulina velutipes (Curt. ex Fr.) Sing.) and the effect of mycelium cultivation conditions on the composition and proportions of individual FA were investigated. Palmitic and linoleic acids were found to be major acids produced by P. ostreatus growing on solid agar medium and in a submerged culture with a synthetic medium. The composition of minor FA in P. ostreatus was dependent on cultivation conditions. Surface cultivation of its mycelium yielded pentadecanoic, octadecenoic, and stearic acids. Submerged cultivation additionally yielded undecanoic, myristic, hexadecenoic, and lignoceric acids. The composition of free FA in F. velutipes showed no significant differences from that of P. ostreatus. Variation in the C/N ratio in the cultivation medium affected both the FA composition in P. ostreatus and F. velutipes and the relationship between saturated and unsaturated FA.

[The use of gliadin genetic markers in the selection of winter wheat in Krasnodar]. / Ispol'zovanie fliadinovykh geneticheskikh markerov v slektsii ozimoi pshenitsy v Krasnodare.

Influence of gliadin components blocks on technological and baking grain qualities was investigated. It was shown that interaction of gliadin blocks affects on quality. The 1A4 and 1D4 blocks reduce negative action of the block 1B3 on baking quality. Combinations of gliadin components blocks of first three homeological chromosomes: 5.1.7., 10.1.4., 4.1.7., 5.1.3., 4.1.3 were the best in influence on gluten quality in Krasnodar conditions. It was managed to select lines without adverse Gld 1B3 effect. Good quality varieties: Spartanka, Skifyanka, Pobeda 50, Jirovka, Yuna, Hasarka, Verna, Ofelia, Leda, Rufa, Gorlitsa, Echo were created in the Institute. Evolutional approach, gradual development of quality traits, using of different complementary sources of quality in system of complex stepped hybridization allow to adjust "conveyor" for creation of new high-quality varieties, and gliadin markers method allow to identify them at early stages of selection.

[Specificity of ultrastructural changes in the myocardium of rats after hypokinesia and irradiation]. / Spetsifichnost' ul'trastrukturnykh izmenenii v miokarde krys pri gipokinezii i luchevom porazhenii.

By electron microscopy and morphometry cardiomyocytes of 20 rats gamma-irradiated with a single dose of 180.6 microCi/kg and those of 20 rats exposed to hypokinesia for 10 days were examined. Visually the ultrastructural changes of cardiomyocytes were nonspecific. The morphometric examination revealed specific features of ultrastructural rearrangements in the nuclei and mitochondria of cardiomyocytes of rats on day 10 of hypokinesia and irradiation.

[Ultrastructural changes in the hepatocytes of dogs continuously exposed to chronic low-dose gamma irradiation]. / Ul'trastrukturnye izmeneniia gepatotsitov sobak v usloviiakh postoiannogo khronicheskogo gamma-oblucheniia v malykh dozakh.

Electron microscopy of the liver of dogs exposed to chronic 6-year gamma-irradiation from the CO60 source demonstrated early changes in the hepatocyte structure at a relatively low dosage of 63 rad for 3 years. A comparative study of the submicroscopic reaction of hepatocytes of 3 groups of test dogs showed pronounced changes in the endoplasmatic reticulum: vacuolar transformation balloon dystrophy. The heterogeneity of ultrastructural changes of different hepatocytes was probably associated with a simultaneous development of processes of injury, reparation and adaptation of intracellular structures during the long-term gamma-irradiation exposure. Parallel development of these processes assured reparative biosynthesis to maintain the normal hepatic function.

[Ultrastructure of the lymph nodes of dogs under prolonged external gamma irradiation]. / Ul'trastruktura limfaticheskikh uzlov u sobak pri dlitel'nom vneshnem gamma-obluchenii.

The purpose of the present investigation was electron microscopy study of lymph nodes of dogs exposed to chronic gamma-irradiation during 6 years (with a total dose of 125 rad/year). The exposure induced changes in the cell composition of the paracortical regions due to a decrease of the count of small lymphocytes and a predominant increase of young blast cells with an altered ultrastructure. Chronic gamma-irradiation led to an increase of the number of plasma cells and emergence of intermediate cell forms due to "plasmatization" of lymphocytes and reticular cells.