Comparative analysis of baking qualities of grain of winter rye varieties with various short-stem types

A comparative assessment of winter rye varieties with recessive polygenic and dominant monogenic short-stem types was carried out with respect to processing and baking qualities. It is shown that dominant short-stem varieties are significantly inferior to varieties with a recessive type in grain test weight, starch content, volume yield of pan bread, crumb porosity, and staling rate, but are significantly superior to them in water extract viscosity and form ratio of hearth bread. Differences are found in the content of amylose and amylopectin, their effect on the baking properties of rye grain is shown. The importance of creating low-amylose rye varieties with a better baking quality is pointed out.     

Daily dynamics of bacterial numbers, CO2 emissions from soil and relationships between their wavelike fluctuations and succession of the microbial community

The daily dynamics of the number of copiotrophic and oligotrophic bacteria (in colony-forming units) and CO₂ emissions from cultivated soils after short- and long-term disturbances were studied for 25–27 days in a microfield experiment. The relationship of the wavelike fluctuations of the bacterial number and CO₂ emission with the succession of the soil microbial community was determined by the polymerase chain reaction method—denaturing gradient gel electrophoresis (PCR-DGGE). Short-term disturbances involved the application of organic or mineral fertilizers, pesticides, and plant residues to the soils of different plots. The long-term effect was a result of using biological and intensive farming systems for three years. The short-term disturbances resulted in increased peaks of the bacterial number, the significance of which was confirmed by harmonics analysis. The daily dynamics of the structure of the soil microbial community, which was studied for 27 days by the DGGE method, also had an oscillatory pattern. Statistical processing of the data (principal components analysis, harmonics and cross-correlation analyses) has revealed significant fluctuations in the structure of microbial communities coinciding with those of the bacterial populations. The structure of the microbial community changed within each peak of the dynamics of the bacterial number (but not from peak to peak), pointing to the cyclical character of the short-term succession. The long-term effects resulted in a less intense response of the microbiota—a lower rate of CO₂ emission from the soil cultivated according to the organic farming system.     

Influence of Land Use on the Physical Properties of Chernozems in the Forest-Steppe Zone of Western Siberia

Eurasian Soil Science - The land use type and agricultural practices significantly affect the aggregate state and many physical properties of soils. In this study, we provide a comparative...     

Microelements in soils of conjugated landscapes with different degrees of hydromorphism in the Kamennaya Steppe

The effect of the hydromorphism degree on the content and profile distribution of the microelements (Mn, Zn, Cu, Cr, Ni, Pb, and Cd) was studied in a conjugate series of Kamennaya Steppe soils containing segregated agrochernozems, hydrometamorphized agrochernozems, and agrohumus-hydrometamorphic typical soils. An attempt was made to reveal the types and subtypes in the profile distributions of the total and mobile heavy metals. It was found that the distributions of the total and acid-extractable heavy metals followed an accumulation type in the profiles of all the studied soils. An eluvial type of distribution was revealed for the mobile microelements. A correlation between the properties of the soils and the contents of the elements in the soil profile was shown.     

Daily dynamics of cellulase activity in arable soils depending on management practices

The daily dynamics of cellulase activity was studied during 27 days by the cellophane membrane method on soils managed using the conventional high-input farming system (application of mineral fertilizers and pesticides) and the biological conservation farming system (application of organic fertilizers alone) in a microfield experiment. The regular oscillatory dynamics of the cellulase activity were revealed and confirmed by the harmonic (Fourier) analysis. The oscillatory dynamics of the cellulase activity had a self-oscillatory nature and was not directly caused by the disturbing impacts of both the uncontrolled (natural) changes in the temperature and moisture (rainfall) and the controlled ones (the application of different fertilizers). The disturbing impacts affected the oscillation amplitude of the cellulase activity but not the frequency (periods) of the oscillations. The periodic oscillations of the cellulase activity were more significant in the soil under the high-input management compared to the soil under the biological farming system.     

The structure of the microbial communities in low-moor and high-moor peat bogs of Tomsk oblast

The number, structure, and physical state of the microbial communities in high-moor and low-moor peat bogs were compared. Distinct differences in these characteristics were revealed. The microbial biomass in the high-moor peat exceeded that in the low-moor peat by 2–9 times. Fungi predominated in the high-moor peat, whereas bacteria were the dominant microorganisms in the low-moor peat. The micromycetal complexes of the high-moor peat were characterized by a high portion of dark-colored representatives; the complexes of the low-moor peat were dominated by fast-growing fungi. The species of the Penicillum genus were dominant in the high-moor peat; the species of Trichoderma were abundant in the low-moor peat. In the former, the bacteria were distinguished as minor components; in the latter, they predominated in the saprotrophic bacterial complex. In the high-moor peat, the microorganisms were represented by bacilli, while, in the low-moor peat, by cytophages, myxobacteria, and actinobacteria. The different physiological states of the bacteria in the studied objects reflecting the duration of the lag phase and the readiness of the metabolic system to consume different substrates were demonstrated for the first time. The relationships between the trophic characteristics of bacterial habitats and the capacity of the bacteria to consume substrates were established.     

Multiple divergent selection on viscosity of a water extract of winter rye

Results of ten cycles of divergent selection on water extract viscosity (WEV) based on varieties of winter rye Al’fa and Moskovskaya 12 are presented. Efficiency of selection depended both on genotype of a variety and direction of selection. Selection in a plus-direction was more effective than in a minus-direction. After ten cycles of selection, the potential of WEV increased in high viscosity populations by 3.3–6.0 times, while it decreased by 2.6–3.5 times in low viscosity populations. The asymmetry of the response was detected during the first cycle of the selection and it remained in all subsequent cycles. The high viscosity populations were more yielding (by 23.8%) than low viscosity populations and had the best baking qualities of grain. Their superiority manifested the most strongly by grain unit (by 7.9%), weight of 1000 grains (by 23.4%), falling number (by 90 s), amylogram height (by 5.4 times), and gelatinization temperature of starch (by 3.2°С). From low viscosity populations, strongly blurring bread with large pores and sticky and restive crumb was produced. Prospects of selection of baking and fodder varieties of a winter rye based on selection of genotypes with high and low WEV are discussed.