67 research outputs found
Nomenclatural standards and genetic passports of potato cultivars bred at the Leningrad Research Institute for Agriculture “Belogorka”
In the present paper, the potato cultivars bred at the Leningrad Research Institute for Agriculture “Belogorka”, were taken as an example for demonstrating the results of elaboration of methodological approaches that are currently developed at the N.I. Vavilov Institute of Plant Genetic Resources (VIR) for the preparing of nomenclatural standards and their genotyping. In 2018, joint research of VIR scientists and breeders from the Leningrad Research Institute for Agriculture “Belogorka” began in the field of preparing nomenclatural standards for potato cultivars bred at this institute. Nomenclatural standards were prepared according to the ‘International Code of Nomenclature for Cultivated Plants’. Plant material for herbarium specimens was collected in the experimental field of the “Belogorka” Institute in 2018 by cultivar authors and handed over to the VIR Herbarium of cultivated plants, their wild relatives and weeds (WIR). The plant material included stems with inflorescences and later - tubers of 21 cultivars which were bred at the “Belogorka” Institute. Two precultivars undergoing State variety testing and three breeding clones were also included in this study. Just before herbarium preparation, the obtained plant material was photographed, plant morphological characters described, and the results compared with the description given in such official documents as the “Cultivar Questionnaireˮ and “Description of selection achievementˮ. The nomenclatural standards of 21 cultivars registered in the VIR Herbarium Database and transferred for conservation to the VIR herbarium, are published in this paper. Before herbarium preparation, the plant material was sampled for DNA extraction and subsequent genotyping and molecular screening. The genetic passports include information about the polymorphism of 10 chromosome-specific microsatellite loci, as well as the data on the presence/absence of diagnostic fragments of 12 markers of the 11 R-genes conferring resistance to diseases and pests, and for some cultivars – the information about their cytoplasm type. These genetic passports are valuable not only because different types of DNA markers were used in their preparing (SSR, SCAR and CAPS markers of the R genes; markers specific to different loci of the nuclear and organelle genomes), but first of all because of the material itself, as the DNA samples were isolated from the plants with the assigned status of nomenclatural standard for each particular cultivar. Based on the genetic passports data, trueness to type of the “Belogorka” cultivar samples obtained from various sources was verified
Oscillations and waves in solar spicules
Since their discovery, spicules have attracted increased attention as energy/mass bridges between the dense and dynamic photosphere and the tenuous hot solar corona. Mechanical energy of photospheric random and coherent motions can be guided by magnetic field lines, spanning from the interior to the upper parts of the solar atmosphere, in the form of waves and oscillations. Since spicules are one of the most pronounced features of the chromosphere, the energy transport they participate in can be traced by the observations of their oscillatory motions. Oscillations in spicules have been observed for a long time. However the recent high-resolutions and high-cadence space and ground based facilities with superb spatial, temporal and spectral capacities brought new aspects in the research of spicule dynamics. Here we review the progress made in imaging and spectroscopic observations of waves and oscillations in spicules. The observations are accompanied by a discussion on theoretical modelling and interpretations of these oscillations. Finally, we embark on the recent developments made on the presence and role of Alfven and kink waves in spicules. We also address the extensive debate made on the Alfven versus kink waves in the context of the explanation of the observed transverse oscillations of spicule axes
Electronic properties and phase transitions in low-dimensional semiconductors
We present the first review of the current state of the literature on
electronic properties and phase transitions in TlX and TlMX2 (M = Ga, In; X =
Se, S, Te) compounds. These chalcogenides belong to a family of the
low-dimensional semiconductors possessing chain or layered structure. They are
of significant interest because of their highly anisotropic properties, semi-
and photoconductivity, non-linear effects in their I-V characteristics
(including a region of negative differential resistance), switching and memory
effects, second harmonic optical generation, relaxor behavior and potential
applications for optoelectronic devices. We review the crystal structure of TlX
and TlMX2 compounds, their transport properties under ambient conditions,
experimental and theoretical studies of the electronic structure, transport
properties and semiconductor-metal phase transitions under high pressure, and
sequences of temperature-induced structural phase transitions with intermediate
incommensurate states. Electronic nature of the ferroelectric phase transitions
in the above-mentioned compounds, as well as relaxor behavior, nanodomains and
possible occurrence of quantum dots in doped and irradiated crystals is
discussed.Comment: 70 pages, 38 figure
The Influence of the Degree of Saturation of Crop Rotations with Alfalfa (
The energy storage system of soil maintenance in the irrigation landscapes of the Western Precaspian is based on the use of the second half of summer for the formation of a natural crop phytocenosis (NCP) and plowing it for green fertilizer. The article deals with the formation of plant mass in grain-grass crop rotations, the concentration and accumulation of nutrients in it. The degree of saturation of alfalfa (Medicago sativa L.) and winter wheat (Triticum aestivum L.) with natural crop phytocenosis (NCP) crop rotations ranges from 0 to 100%. The most productive of the studied crop rotations is a four-field with one output field of alfalfa and three fields of winter wheat, after harvesting which in the second half of summer a NCP for green fertilizer is formed. In this crop rotation, 97.4 t of agricultural products were produced on 1 ha of the crop rotation area, including 30.2 t/ha of its non-alienable part from the soil. Accordingly, the removal of N, P2O5 and K2O from the soil increases. The proportion of the returned amount of nutrients from the phytomass inalienable from the soil was (%): N-17.7; P2O5 and 45.3
DYNAMICS OF ENVIRONMENTAL FACTORS AND REALIZATION OF THE POTENTIAL PRODUCTIVITY OF ECOSYSTEMS WITH MEADOW-CHESTNUT SOILS IN THE TEREK-KUMA PERI-CASPIAN LOWLAND
The aim is to reveal theoretically possible productivity of pasture phytocenosis on meadow-chestnut soils in protected area of Terek-Kuma Lowland.Methods. To determine the dynamics of the basic physical and chemical properties of soil, evaporation, humidity coefficient (HC) of the area, the productivity of phytocenoses and utilization factors of photosynthetically active radiation (PAR).Results. Highly productive ephemeral synusia (5 q/ha of air-dry weight) is formed in years with precipitation of 80-85 mm during April - May at a relative humidity of 70-73%, with evaporation of 130-140 mm, humidity coefficient of 0.30, and integral of moisture of 29.8. Decreasing precipitation amount in the same period to 25-26 mm, the relative humidity to 61%, humidity coefficient to 0.06, evaporation to 200-202mm form an integral of aridity of 37.3, where the 0- 24 cm Cl ion content in the soil increase to 5.56 mgEq/100g, the yield of a biomass is reduced to 1.0 q/ha. Increase of 102 mm in rainfall in July – August period results in humidity coefficient increase - 0.21, decrease of Cl- content in horizons of А+В to 1.40 mg-eq./100g. Productivity of grasses and saltwort increases to 21.1q/ha. The utilization factor of PAR by phytocenosis makes up 0,023-0,033 (21.4% share of ephemera, herbs and saltwort make up 78.6%) and had little effect on productivity of phytocenosis.Main conclusion. The formation of a biomass in the meadow-chestnut soil is the result of the combined effects of the amount of rainfall, evaporation, humidity coefficient, the degree and the chemistry of soil salinity. Were calculated multiple regression equations expressing the relationship between these factors
THEORETICALLY POSSIBLE AND PRACTICALLY RELIZABLE PRODUCTIVITY OF THE LIGHT-CHESTNUT SOILS OF THE NORTHERN WEST PRECASPIAN REGION ACORDING TO THE MOISTURE AND SOLINITY (ON EXAMPLE OF KOCHUBEY BIOSPHERE STATION OF PIBR DNC RAS)
Abstract. The article presents the productivity data, the species composition and utilization rates phytocenoses FAR depending on theintegrals of dryness and moisture climate volatility, coefficient of moisture and dynamics of harmful salts in the soil according to years and seasons of the year.Methods.The studies were conducted on light-chestnut carbonate saline soil of Kochubey biosphere stations on the territory of the Terek- Kuma Lowland Precaspianregion in 2011–2013. The calculation of the use of FAR was conducted using the formula A.A. Nichiporovich to determine the theoretically possible yield of plants. Klimatogrammy during these years has been compiled by the method Walter. Stocks above and below ground plant matter into account by the method of A.A.Titlyanova.The names of species given by S.K. Cherepanov.Results. According to the results of our observations, the most important for achieving high productivity ephemeral synusia under these conditions include precipitation for April and May. Between the amount of rainfall in April and May and the productivity of abovegroundphytomass ofephemera direct correlation exists, which in 2011 had a strong, and in the next two years-the average severity. In 2012 the volatility increased, KU fell in 5 times. Such weather conditions contributed to the rise of water-soluble salts to the upper soil horizons and substantial change in species composition phytocenoses. The content Cl- in the layer 0–20 cm over the same period 2011 increased in 3.9 times, SO4--- 1.7 in times. If in 2011 the stepen soil salinity in the layer 0–35 cm characterized as weak, in 2012 the average at the same chloride- sulphate type of salinity. Obviously , an increase in the content of Cl- - ions and its relationship to the S04-- contributed to a dramatic increase in productivity and thistle herbs in 2012. Luxuriant growth of Salsola iberica Sennen et Pau particularly stood.Thus, the formation of a biomass and species composition in the Terek-Kuma Lowland Precaspian is the result of the cumulative effects of different environmental factors, the main ones are: precipitation, air temperature, its relative humidity, evaporation, moisture ratio and the degree of soil salinity and chemistry. These dependencies are expressed by the following multiple regression equation. Depending on climatic conditions, the pasture use phytocoenoses 0,20–0,57 % FAR. Win ephemera and ephemeroids of this amount is an average over years of research about 20 %, the remaining 80%-grasses and thistle, the majority of which occur in Salsola iberica Sennen et Pau, bad eating animals and less valuable as fodder representative thistle. Main conclusion.Our results suggest that, in the context of the Terek-Kuma Lowland there are two peaks of productivity of phytocenoses: first one of ephemeras andephemeroids is in mid-May to early July, the second one of grasses and thistleis in the second half of September. The main factors to achieve high productivity ephemeras and ephemeroids on light-chestnut soil of the North- West Precaspian are about 80–85 mm rainfall during April – May, with average daily air temperature 15–16 °C, its relative humidity 70–73 %, volatility of 130–140 mm, KU 0.30, chloride-sulphate type of salinity in the layer of a low degree of 0–35 cm. In years with heavy rainfall in July and August (102 mm), despite an increase in average daily air temperature to 25–26 °C and volatility to 275mm, a relatively high KU (0.21), the content of Cl-in the layer 0–20 cm reduced 1,40 mg-ekv./100 g, ratio Cl-:SO4-- to 0,59–0,84 and productivity grasses and Salsola iberica Sennen et Pauincreased. The FAR utilization reaches 0.57, of which the biomass of grasses and Salsola iberica Sennenet Pau falls 87.6 % (2012).The task of future research is to determine its phitomeliorative role: removal of salt-forming ions from the soil and itsfurther redistribution in ecosystem, considering the nature of movement on the territory of Salsola iberica Sennen et Pau
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