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排序方式: 共有145条查询结果,搜索用时 156 毫秒
61.
Shahnoza Hazratkulova Ram C. Sharma Safar Alikulov Sarvar Islomov Tulkin Yuldashev Zafar Ziyaev Zakir Khalikulov Zokhid Ziyadullaev Jozef Turok 《Plant Breeding》2012,131(6):716-721
Normalized difference vegetation index (NDVI), which is a measure of leaf greenness (chlorophyll content), is considered to be correlated with crop productivity. This study was conducted to examine genotypic variations for NDVI at different growth stages and its relationship to yield in winter wheat under terminal heat stress. Thirty winter wheat genotypes were evaluated at two locations in 2009–2010 and 2010–2011 in Uzbekistan. The NDVI was recorded at booting, heading, milk and dough stages. The wheat genotypes differed significantly for NDVI at each stage. Grain yield ranged from 3.9 to 6.1 t/ha. Wheat genotypes differed in per cent decline in NDVI from booting to dough stage. However, several high‐yielding genotypes maintained higher NDVI than low‐yielding genotypes when heat stress was evident. The findings suggest change in NDVI during heat stress could be a measure of tolerance. The positive correlation of NDVI with grain yield suggests that it could be used as an indirect selection criterion for identifying physiologically superior, high‐yielding wheat lines under terminal heat stress. 相似文献
62.
Recent plant diversity changes on Europe's mountain summits 总被引:2,自引:0,他引:2
Pauli H Gottfried M Dullinger S Abdaladze O Akhalkatsi M Benito Alonso JL Coldea G Dick J Erschbamer B Fernández Calzado R Ghosn D Holten JI Kanka R Kazakis G Kollár J Larsson P Moiseev P Moiseev D Molau U Molero Mesa J Nagy L Pelino G Puşcaş M Rossi G Stanisci A Syverhuset AO Theurillat JP Tomaselli M Unterluggauer P Villar L Vittoz P Grabherr G 《Science (New York, N.Y.)》2012,336(6079):353-355
In mountainous regions, climate warming is expected to shift species' ranges to higher altitudes. Evidence for such shifts is still mostly from revisitations of historical sites. We present recent (2001 to 2008) changes in vascular plant species richness observed in a standardized monitoring network across Europe's major mountain ranges. Species have moved upslope on average. However, these shifts had opposite effects on the summit floras' species richness in boreal-temperate mountain regions (+3.9 species on average) and Mediterranean mountain regions (-1.4 species), probably because recent climatic trends have decreased the availability of water in the European south. Because Mediterranean mountains are particularly rich in endemic species, a continuation of these trends might shrink the European mountain flora, despite an average increase in summit species richness across the region. 相似文献
63.
Phenylalanine ammonia-lyase activity (PAL, EC 4.3.1.5), total phenolics, soluble proteins, malondialdehyde and metals accumulation in four-week old chamomile (Matricaria chamomilla) plants cultivated in nutrient solution and exposed to low (3 μM) and high (60 and 120 μM) levels of cadmium (Cd) or copper (Cu) for 7 days were studied. High Cd concentrations had a stimulatory effect on PAL activity and soluble phenolics accumulation while high Cu doses decreased soluble proteins in the leaf rosettes. In the roots, extreme stimulatory effects of 60 and 120 μM Cu were observed on PAL activity, phenolics and malondialdehyde accumulation, while protein content was reduced by these Cu doses. Cd accumulation was higher in the leaf rosettes compared to copper, but the opposite was recorded in the roots. Taken together, the stimulatory effect of Cu on phenolic metabolism was recorded, even though high malondialdehyde accumulation may be an indication that phenolics was not sufficient to counteract reactive oxygen species formation thus leading to damage of membrane integrity. In comparison to Cd, Cu had more noticeable effect on the parameters studied to support its strong redox-active properties. These facts in correlation to antioxidative properties of phenolic metabolites are also discussed. 相似文献
64.
Jozef M. Pacyna 《Water, air, and soil pollution》1986,30(3-4):825-835
Measured air concentrations of several trace elements in southern Scandinavia have been related to long range transport and emissions of the same elements from sources in Europe using receptor modelling and statistical trajectory sector analysis. A good agreement, within a factor of 1.5 between estimates and measurements, has been obtained for Mn, Ni, Cu, and As. Significant differences were noted for V and Pb. 相似文献
65.
Tree species selection for land rehabilitation in Ethiopia: from fragmented knowledge to an integrated multi-criteria decision approach 总被引:1,自引:1,他引:0
Bert Reubens Clara Moeremans Jean Poesen Jan Nyssen Sarah Tewoldeberhan Steve Franzel Jozef Deckers Caleb Orwa Bart Muys 《Agroforestry Systems》2011,82(3):303-330
Dryland regions worldwide are increasingly suffering from losses of soil and biodiversity as a consequence of land degradation.
Integrated conservation, rehabilitation and community-based management of natural resources are therefore of vital importance.
Local planting efforts should focus on species performing a wide range of functions. Too often however, unsuitable tree species
are planted when both ecological suitability for the targeted area or preferences of local stakeholders are not properly taken
into account during selection. To develop a decision support tool for multi-purpose species selection, first information needs
to be pooled on species-specific ranges, characteristics and functions for a set of potentially valuable species. In this
study such database has been developed for the highly degraded northern Ethiopian highlands, using a unique combination of
information sources, and with particular attention for local ecological knowledge and preferences. A set of candidate tree
species and potentially relevant criteria, a flexible input database with species performance scores upon these criteria,
and a ready-to-use multi-criteria decision support tool are presented. Two examples of species selection under different scenarios
have been worked out in detail, with highest scores obtained for Cordia africana and Dodonaea angustifolia, as well as Eucalyptus spp., Acacia abyssinica, Acacia saligna, Olea europaea and Faidherbia albida. Sensitivity to criteria weights, and reliability and lack of knowledge on particular species attributes remain constraints
towards applicability, particularly when many species are jointly evaluated. Nonetheless, the amount and diversity of the
knowledge pooled in the presented database is high, covering 91 species and 45 attributes. 相似文献
66.
Findoráková Lenka Šestinová Oľga Matik Marek Hančuľák Jozef Bureš Radovan 《Journal of Soils and Sediments》2022,22(9):2448-2458
Journal of Soils and Sediments - To evaluate the ecological risk, physico-chemical properties, and the impact of anthropogenic sources on permanent eighteen samples of grass vegetation soils (PGVS)... 相似文献
67.
68.
Huber S Roosje PJ Janda J Schnyder M Jungi TW Bertoni G Zurbriggen A Burgener IA 《Veterinary immunology and immunopathology》2011,144(3-4):247-254
Toll-like receptors recognize pathogen-associated molecular patterns of microbial origin, and ligand recognition results in the production of different immune mediators such as pro-inflammatory cytokines, interferon, reactive oxygen and nitrogen intermediates, and upregulation of costimmulatory molecules. As these receptors have a critical role in linking pathogen recognition to induction of inflammation and innate as well as adaptive immunity, there is tremendous interest in understanding how the tissue and cell-type expression of TLRs is regulated and its influence on the local innate immune response. While TLRs are well studied in humans and rodents, to date little is known about them in dogs. The purpose of this study was to develop canine specific antibodies against TLR2, 4, 5 and 9 that were used to measure relative expression of these TLRs in healthy and reactive canine mesenteric lymph nodes. All 8 rabbit sera (2 each for TLR2, 4, 5 and 9) were strongly positive in ELISA against the respective 2 peptides per TLR used for immunization. The purified antibodies selected specifically detected a protein band with an apparent size of approximately 70 kDa in lysates of canine PBMCs by Western blotting. Immunostaining was observed with purified antibodies against TLR4, 5 and 9, whereas for canine TLR2, staining was only observed with the unpurified antibodies. In the mesenteric lymph node of healthy dogs, the overall staining pattern was very similar for TLR4 and 5 with positive cells predominantly found in the internodular areas and lower part of the cortex. Compared to the TLR4 and 5, more cells stained positive for TLR9 especially in the lymphoid nodules. The reactive lymph nodes contained more TLR4 and 9 positive cells. Moreover, a shift of TLR-9 positive cells from the lymphoid follicles to the deep cortex and medullary cords was observed. Whereas TLR9 co-localized with CD79-positive areas, TLR4 and 5 antibodies stained cells primarily in the CD3-positive areas. All three TLR antibodies stained cells within the area that co-localized with lysozyme-positive cells. In conclusion, this study demonstrates that the antibodies generated against canine TLR 4, 5 and 9 identify the expression of these TLRs in formalin-fixed canine lymph nodes and demonstrate increased expression in reactive canine mesenteric lymph nodes. 相似文献
69.
Lutishoor Salisbury Jozef Laincz Jeremy J. Smith 《Journal Of Agricultural & Food Information》2013,14(3):250-266
This study compares undergraduate and graduate students’ preferences for information sources. It found that the largest percentage of undergraduates ranked Google Scholar, a scholarly database, as their 1st or 2nd choice for an information source, followed by Google, library scholarly databases, the library catalog, and library staff. The largest percentage of graduate students ranked library scholarly databases as their 1st or 2nd preference, followed by Google Scholar, the library catalog, Google, and library staff. There seems to be a connection between attendance in a library instruction session and the choice of library scholarly online databases. 相似文献
70.
Antagonism of local isolates of Trichoderna spp. on citrus root rot disease by Fusarium solani in the mekong delta of vietnam 下载免费PDF全文
Duong Minh Jozef Coosemans Le Lam Cuong Ester Vandersmissen Pham Van Kim 《浙江大学学报(农业与生命科学版)》2004,30(4):392-392
The local isolates of Trichoderrma spp. and Fusariun solani were colected from citrus orchards in the Mekong delta of Vietnam and isolated on PDA, PDB and TSM medium for antagonism and Koch's postulate testing. The results showed that the high chitinolytic enzymes content of Trichoderma isolates can antagonise with Fusarium solani isolates by preventing the germination of Fusarium macroconidia in in-vitro condition. There are five promising isolates of Trichoderna spp. having high antagonism with Fusarium solani. These Trichoderma isolates also grew well in rice straws, maize stems, weeds and water hyacinth biowaste materials. These results supply the promising trend for biological control of root rot disease on citrus orchards of the Mekong delta. 相似文献