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Potato virus Y (PVY) strains were originally defined by interactions with different resistance genes in standard potato cultivars. Five distinct strain groups are defined that cause local or systemic hypersensitive responses (HRs) in genetic background with a corresponding N gene: PVY(O), PVY(N), PVY(C), PVY(Z), and PVY(E). The nucleotide sequences of multiple isolates of PVY(O) and PVY(N) differ from each other by ≈8% along their genomes. Additionally, complete genome sequences of multiple recombinant isolates are composed of segments of parental PVY(O) and PVY(N) sequences. Here, we report that recombinant isolate PVY-L26 induces an HR in potato 'Maris Bard' carrying the putative Nz gene, and is not recognized by two other resistance genes, Nc and Ny(tbr). These genetic responses in potato, combined with the inability of PVY-L26 to induce vein necrosis in tobacco, clearly define it as an isolate from the PVY(Z) strain group and provide the first information on genome structure and sequence of PVY(Z). The genome of PVY-L26 displays typical features of European NTN-type isolates with three recombinant junctions (PVY(EU-NTN)), and the PVY-L26 is named PVY(Z)-NTN. Three typical PVY(NTN) isolates and two PVY(N) isolates, all inducing vein necrosis in tobacco, were compared with PVY-L26. One PVY(NTN) isolate elicited HR reactions in Maris Bard, similar to PVY-L26, while two induced a severe systemic HR-like reaction quite different from the quasi-symptomless reaction induced by two PVY(N) isolates. 'Yukon Gold' potato from North America produced HR against several PVY(NTN) isolates, including PVY-L26, but only late and limited systemic necrosis against one PVY(N) isolate. Consequently, according to symptoms in potato indicators, both PVY(Z) and PVY(NTN) isolates appeared biologically very close and clearly distinct from PVY(O) and PVY(N) strain groups. 相似文献
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Analysis of methodological documents, Russian and foreign standards, and scientific publications has been performed to reveal best global practices and current trends in the improvement of laboratory phytotesting. It is proposed to increase the number of simultaneously used test cultures and the range of simultaneously controlled test functions at the first (screening) stage of phytotest to increase the information value of laboratory phytotests. Attention is focused on the assurance of the statistical reliability of test results. The advisability of creating universal regulations of Russian Federation for phytotesting methods to unify approaches to the ecological evaluation of soils. 相似文献
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Olga Nikolaeva Marina Rozanova Mikhail Karpukhin 《Journal of Soils and Sediments》2017,17(4):1045-1053
Purpose
The objective of this research is to find out the spatial distribution of different traffic-related contaminants in urban topsoils across a highway (125,000 vehicles per day) in the city of Moscow, Russia.Materials and methods
The topsoils (0–3 cm depth) were sampled 1, 6, 10, 18, and 50 m perpendicular to the roadbed in three replicates 10 m apart. We analyzed total petroleum hydrocarbons (TPH), polycyclic aromatic hydrocarbons (PAH), heavy metals in total and phyto-available forms (HM; Cu, Zn, and Pb), and deicing salts (DS; Cl?). The TPH were extracted with carbon tetrachloride and detected by spectrometry and PAH were extracted with methylene chloride, separated by high-performance liquid chromatography, and determined by fluorescence detector. Total HM were extracted by microwave acid digestion with aqua regia and phyto-available forms were extracted by NH4OAc and determined by inductively coupled plasma mass spectrometry. The DS were analyzed using an ion liquid chromatograph with a conductometric detector.Results and discussion
Heavy soil pollution was found within 1–6 m of the road. The TPH, B[a]P, and phyto-available HM concentrations exceeded permissible levels for Russia, while total HM and DS did not. The contaminant contents sharply decreased 10 m from the road. Within 10–50 m, they reached background levels, while PAH levels were elevated. We attribute this to the greater age of soils at 10–50 m than 1–6 m from the road. The different contaminant distribution patterns are attributed to their different transportation pathways: TPH, DS, and HM generally reach soils through road spray, splashes, melting snow moved from the road surface to roadsides, and aerosol sedimentation, whereas PAH are mainly transported as airborne particles and are thus able to reach more distant locations.Conclusions
Traffic-related soil pollution creates ecotoxicological and human-health risks. Distribution patterns vary by type of soil contaminant. The influence of the road on soil contamination was greatest within 10 m from the roadbed for TPH, HM, and DS and within 50 m for PAH. The increased PAH concentration levels with increased distance from the road highlights the importance of PAH monitoring in roadside soils.5.
The effect of five Russian and foreign hydrogels on the water retention curve (WRC) and the related physical parameters of soils and sediments differing in their genesis and degree of dispersion has been considered on the basis of a proprietary version of the equilibrium centrifugation method. The new version of the method with the use of a high-speed centrifuge has allowed obtaining WRC in a wide range of matric potentials from 0 to 3000 J/kg (pF = 4.5) with the experimental estimation of almost all the soil-hydrological constants. The first analysis of strongly swelling polymer hydrogels (SSPHs) on WRC and the structural curves of the pore size distribution in heavy-textured soils has been performed, and the possibility has been shown of increasing their water capacity at the swelling of SSPHs in the region near water saturation. The most efficient is the use of SSPHs in light soils, which allows their water retention to be brought to the level of native loamy sands and loams in the SSPH content range of 0.1–0.3% of the enclosing coarse material. The best characteristics were observed for the Russian hydrogel VUM developed by the Institute of Technical Chemistry of the Urals Branch of the Russian Academy of Sciences and produced by the Urals Plant for Chemical Reagents. 相似文献
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Golovenko Ekaterina Lyashenko Svetlana Akimova Svetlana Mitina Lyubov Mulenkova Elena Belarbi El-Hassan Guil-Guerrero José Luis 《Plant foods for human nutrition (Dordrecht, Netherlands)》2021,76(3):385-393
Plant Foods for Human Nutrition - γ-linolenic acid (GLA, 18:3n-6) is a bioactive fatty acid (FA) that exerts several healthy actions; however, its occurrence is restricted to a few oils. The... 相似文献
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Antiviral activity of betulin,betulinic and betulonic acids against some enveloped and non-enveloped viruses 总被引：3，自引：0，他引：3
Antiviral properties of betulin, betulinic and betulonic acids were investigated in cell cultures infected with herpes simplex type I, influenza FPV/Rostock and ECHO 6 viruses. All studied triterpenes were active against herpes simplex virus. Betulin and especially betulinic acid also suppressed ECHO 6 virus reproduction. 相似文献
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T. I. Ivanova N. P. Kononova N. V. Nikolaeva A. P. Chevychelov 《Eurasian Soil Science》2006,39(6):661-666
The population of saprotrophic, oligotrophic, and nitrogen-fixing microorganisms was determined in cryogenic forest soils of central Yakutia. The number of saprotrophic bacteria ranged between 108 and 1010 cell/g of soil. In the soils of Buryatia, this parameter (108) was 4 orders of magnitude as high as in the soils of European Russia (106). According to the increase in the total number of microorganisms in the soils studied, the forests were arranged in the following sequence: pine forest—birch forest—larch forest. The main factor that determined the saturation of the studied frozen soils with microorganisms was the landscape, i.e., the forest type and the soil type. Of minor importance were the weather conditions of the year or season investigated, which defined the intra-and interspecies variation of the total population of the soil microorganisms. 相似文献
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Lyubov E. Burlakova Alexander Y. Karatayev Vadim A. Karatayev Marsha E. May Daniel L. Bennett Michael J. Cook 《Biological conservation》2011,(1):155-165
The biodiversity crisis, particularly dramatic in freshwaters, has prompted further setting of global and regional conservation priorities. Species rarity and endemism are among the most fundamental criteria for establishing these priorities. We studied the patterns of rarity and the role of rare species in community uniqueness using data on freshwater bivalve molluscs (family Unionidae) in Texas. Due to the large size and gradients in landscape and climate, Texas has diverse and distinct unionid communities, including numerous regional and state endemic species. Analysis of the state-wide distribution and abundance of Unionidae allowed us to develop a non-arbitrary method to classify species rarity based on their range size and relative density. Of the 46 Unionidae species currently present in Texas, 65% were classified as rare and very rare, including all state and regional endemics. We found that endemic species were a critical component in defining the uniqueness of unionid communities. Almost all endemics were found exclusively in streams and rivers, where diversity was almost double that of lentic waters. Man’s ongoing alteration of lotic with lentic waterbodies favors common species, and dramatically reduces habitat for endemics, contributing to homogenization of unionid fauna. We identified hotspots of endemism, prioritized species in need of protection, estimated their population size, and recommended changes to their current conservation status. 相似文献
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