On the manifestation of solonetzic properties in soils of the steppe and dry steppe zones in the south of Ukraine

Solonetzic soils are widespread in the south of Ukraine; some of them are represented by low-sodium solonetzes whose diagnostics is complicated by the absence of correspondence between the low content of exchangeable sodium and the clearly pronounced features of the illuvial solonetzic horizon. The statistical treatment of available literature, personal materials, and the materials of soil surveys in the south of Ukraine demonstrated that the diagnostics of low-sodium solonetzes should be based on the assessment of the degree of illuviation in the soil profile. It was shown that the degree of correlation between the content of exchangeable sodium and the degree of illuviation of the soil profile varies in dependence on the size of the statistical sample and differs for the low-sodium and medium-sodium solonetzes. Two scales characterizing the degree of soil illuviation were developed for these soil groups. It is suggested that these scales should be applied during soil surveys in the areas with solonetzic soils.     

A microsatellite and morphological assessment of the Russian National cultivated potato collection

The germplasm collections of the Vavilov Institute of Plant Industry, Russia represent the first germplasm collection made for potatoes, now numbering 8,680 accessions. It has tremendous historical and practical importance and a rich history, having been used to document a polyploid series in the cultivated species, to formulate initial taxonomic hypotheses in potato, for studies of interspecific hybridization, and serving as the germplasm base for Russian breeding efforts. Despite its importance and size, there has never been a study of its molecular diversity, and there were many gaps in its passport data. The purpose of the present study is to obtain morphological, ploidy, and microsatellite (SSR) data needed to set up a useful subset of the collection of cultivated potatoes and closely related wild species, and to use this collection to study cultivated potato taxonomy and phylogeny. Through assessments of viability, passport data, and chromosome counts, we selected a subset of 238 cultivated and 54 wild accessions. A morphological and nuclear SSR study of these collections distinguished only three cultivated species: Solanum curtilobum, S. juzepczukii and S. tuberosum, not the many more cultivated potato species of prior taxonomic treatments. The SSR study supports the ideas of S. acaule as one of the parental species for S. curtilobum and S. juzepczukii. The morphological and SSR results are very similar to other recent studies of cultivated species, and show the need to reclassify the collection of cultivated potatoes by modern taxonomic criteria.     

Quantification of the areas of saline and solonetzic soils in the Ural Federal Region of the Russian federation

Soil Salinization Map of Russia on a scale of 1: 2500000 (the paper version) has been used for compiling an electronic map of the Ural Federal Region and an attribute database containing twelve characteristics of soil salinization. The areas of saline soils have been quantified for the entire region and its administrative districts. The total area of saline soils in the 0- to 200-cm layer averages up to 6.85 million ha or 5.53% of the plains in the region. The area of soilssaline in the 0- to 100-cm layer averages up to 4.91 million ha, including 4.13 million ha of weakly solonchakous soils (84%) and 0.78 million ha of solonchakous ones (16%). More than half of them (58.3%) are assigned to the moderately and strongly saline soils. The soils saline in the 0- to 100-cm layer are characterized by the neutral salinization type (45%) or the types of soda salinization and neutral salinization with soda (55%). The areas of the region with saline soils are dominated by solonetzic microassociations. The average area of the solonetzes is about 3 million ha. The area of solonchaks is about 0.09 million ha. The area of saline soils is the greatest in Kurgan oblast and the lowest in Sverdlovsk oblast and the Yamal-Nenets autonomous okrug. The formation of saline soils in the Ural Federal Region is related to the climatic conditions of the steppe zone with insufficient moistening and lithologicgeomorphologic conditions (saline Paleogene-Neogene deposits and poor drainage of the area).     

Efficient molecular and genetic technique for identification of Salmonella and Proteus strains

Fast microorganism genotyping technique has been developed with the use of the double distribution and selective labeling method (DDSL) for identification of disease-associated serotypes of Salmonella and Proteus strains. Isolates have been obtained from poultry tissues and dung from different places in various years. The results of strain genotyping conform to epizootological data. The method can be recommended for practical application in ascertainment of transmission of infectious disease and localization of bacterial pathogen source.     

Biological activity of soddy-pale-podzolic soils under coniferous-deciduous forest parks in the city of Mogilev

The physicochemical properties, enzymatic activity, number and biomass of soil microorganisms was determined by direct microscopic methods in the anthropogenically changed loamy sandy-loamy soddy-pale-podzolic soils under forest parks (the city of Mogilev) with the predominance of meadow-weed plants in the ground cover. The urban environment had a more toxic influence on the biological activity of the soils than recreation. A more intense transformation of the litter substrate and accumulation of biogenic elements was revealed in the old-plowed sandy loamy soils under the urban coniferous-deciduous plantations as compared to these processes in the soils of the recreational pine forests in the vicinity of Mogilev.     

Genetic diversity and origin of cultivated potatoes based on plastid microsatellite polymorphism

The origin of cultivated potatoes has remaining questions. In this study, 237 accessions of all cultivated species and 155 accessions of wild species closely related to cultivated potatoes, including their putative ancestors, were analyzed using 15 plastid microsatellites (SSRs) to investigate genetic diversity and their relationships with the wild species. We here used polymorphic plastid SSRs we developed from potato plastid genome sequences as well as already known plastid SSR markers. All 15 loci were polymorphic and identified a total of 127 haplotypes. Dramatic decreases in levels of genetic diversity were revealed in landraces in comparison with wild ancestor species. The plastid SSR results showed a decrease in haplotype number and diversity from Peru to both north and south. Phylogenetic analysis revealed two distinct groups. One of them, group A, contained the majority of accessions of cultivated species of the Solanum tuberosum Andigenum group including all accessions of cultivated diploid and triploid cytotypes of this group (S. chaucha, S. phureja, and S. stenotomum by a former taxonomic system) and most of tetraploid accessions of the S. tuberosum Andigenum group (S. tuberosum subsp. andigenum), and the majority of accessions of wild ancestors from the northern members of the S. brevicaule complex. Another group B comprised most of the wild species accessions and almost exclusively hybrid cultivated species which have introgressed plastid genomes from the other wild gene pools. Lack of clustering of traditional cultivated species (as used above) support a revised group classification of S. tuberosum.     

Estimation of the areas of salt-affected soils in the European part of Russia on the basis of a digital map of soil salinization on a scale of 1 : 2.5 M

A digital version of the map of salt-affected soils on a scale of 1 : 2.5 M has been used to calculate the areas of these soils in the four federal okrugs (the Southern, Central, Volga, and Northwestern) of European Russia. The total area of soils with soluble salts in the upper meter reaches 23.3 million ha. More than half of them are solonchakous soils (with soluble salts in the layer deeper than 30 cm), and about 25% are saline from the surface. Soils of sulfate and chloride-sulfate salinization predominate (>50% of the area of salt-affected soils). Alkaline soda-saline soils and soils with the participation of soda comprise about 6%. We consider this value to be underestimated and requiring refinement, because soils of solonetzic complexes with neutral salts in the upper horizons may also contain soda in the solonetzic and subsolonetzic horizons, which was not always taken into consideration upon assessing the chemical composition of the salts. Solonetzes proper and solonetzic soils predominate among the salt-affected soils in the European part of Russia. The area of solonetzes is up to 9.4 million ha. The area of solonetzic soils (including solonetzic soils with salts in the layers of 0–100 and/or 100–200 cm) is 15.5 million ha. The highest percentage (32.2%) of salt-affected soils is in the Southern federal okrug.     

Salinization dynamics in irrigated soils of the Svetloyarsk irrigation system,Volgograd oblast

On the basis of soil surveys performed by the Volgograd hydrogeological reclamation expedition in 1998 and 2006, published data, and original materials obtained by the authors, the dynamics of soil salinization within the Svetloyarsk irrigation system in Volgograd oblast during the irrigation and post-irrigation periods have been traced. It is found that high irrigation rates under conditions of poor drainage and closed drainage basins upon both shallow (within the Caspian Lowland) and relatively deep (on the Ergeni Upland) occurrence of saline groundwater and the presence of natural salts in the soils and subsoils lead to the rise in the groundwater level above the critical level and the development of secondary salinization in the previously surfacesaline, deeply saline, and even nonsaline soils. During the post-irrigation period (15–18 years) under modern climatic conditions, the groundwater level has been descending to a depth of more than 3 m, and the degree of salinity in the upper meter of light chestnut and meadow-chestnut soils has decreased owing to the leaching of salts with atmospheric precipitation.     

Alkalinity of virgin solonetzes in northern Kalmykia (the Arshan-Zel’men Experimental Station)

The alkalinity of virgin solonetzes of the Ergeni Upland, Ergeni Plain, and Sarpinsk Lowland has been studied. These soils are characterized by the neutral salinization and the high alkalinity of the solonetzic and subsolonetzic horizons. The analysis of the soil water extracts demonstrated that the highest alkalinity is typical of the subsolonetzic horizons containing calcium carbonates (the B2 and BCca horizons). In the solonetzic horizons without CaCO₃, the alkalinity is lower despite the high exchangeable sodium percentage (up to 42%). The alkalinity of the solonetzic and subsolonetzic horizons may be conditioned by two processes: (a) the hydrolysis of the exchange complex (EC) containing sodium (EC-Na + H₂O ↔ EC-H + Na⁺ + OH⁻) and (b) the reaction of the ion exchange with the substitution of calcium for sodium in the exchange complex (EC-2Na + CaCO₃ ↔ EC-Ca + 2Na⁺ + CO₃²⁻). Calculations performed on the basis of the thermodynamic equations of the physicochemical equilibria according to the LIBRA program indicate that soda is absent in the solonetzic horizons, whose alkalinity is related to the carbonatecalcium equilibria. The high alkalinity of the calcareous subsolonetzic horizons is related to the presence of soda in combination with CaCO₃. The formation of soda in these horizons is due to the reaction of ion exchange described by Gedroits.