排序方式: 共有121条查询结果,搜索用时 15 毫秒
21.
Emmanouil A. Markakis Georgios C. Koubouris Chrysi K. Sergentani Eleftherios K. Ligoxigakis 《European journal of plant pathology / European Foundation for Plant Pathology》2017,149(2):277-283
In the present study, four Greek (Agiorgitiko, Asyrtiko, Roditis and Xinomavro) and one international (Soultanina) grapevine cultivars (Vitis vinifera L.) were screened for their resistance to Phaeomoniella chlamydospora. Artificial inoculation was carried out by drilling a hole into the trunk and injecting a concentrated conidial suspension into the vessels. Disease reactions were evaluated in an 87-day assessment period, on the basis of external symptoms (disease incidence, disease severity and mortality) and by calculating the relative areas under disease progress curves (relative AUDPC). The extension of vascular browning as well as the isolation ratio along the inoculated vine trunks were also taken into account as additional parameters for evaluating resistance. The results indicated that the resistance of grapevine cultivars to P. chlamydospora varied significantly. ‘Agiorgitiko’ and ‘Soultanina’ were susceptible, whereas ‘Asyrtiko’ and ‘Xinomavro’ were resistant; ‘Roditis’ showed an intermediate level of resistance. Cultivars’ resistance was mostly distinguished in terms of the extension of vascular browning and pathogen isolation ratio. On the contrary, the disease incidence, final disease severity, mortality and relative AUDPC provided less distinctive efficiency in resistance evaluation. The robust methodology presented here could be useful in rapid evaluation experiments for future screening programs to search and recognize natural resistant sources within grapevine genotypes against P. chlamydospora. 相似文献
22.
Anastasia L. Lagopodi Georgios T. Tziros 《European journal of plant pathology / European Foundation for Plant Pathology》2010,128(3):311-316
Alternaria dauci (Kühn) Groves and Skolko, the cause of leaf blight of carrot, was observed to produce chlamydospores and microsclerotia in vitro. Four different isolates produced chlamydospores on potato dextrose agar, V8 agar and Czapek-Dox agar at 10, 18 and 28°C, from neighbouring cells of hyphae of the submerged mycelium, forming long chains. Formation of chlamydospores was completed in a multiple stage process, including swelling of cells, development of secondary septa, rounding up of cells and cell wall thickening. Mature chlamydospores were released from the mycelium mostly in clusters and in short or long chains, and sometimes in pairs. They were globose to ellipsoid, smooth or verrucose, pale brown in colour, and averaged 13.87?×?11.37 μm, (length × width). Microsclerotia were formed on PDA, by only one isolate, at 28°C first at the edges of the colony, by close contact of hyphae that exhibited extensive branching and intermingling. In their final form microsclerotia were multi-celled, closely attached masses of short and broad dark grey cells, less compact woven at the edges of the microsclerotium. This is the first illustration of chlamydospore and microsclerotia formation in Alternaria dauci. 相似文献
23.
Topramezone is a new herbicide for post-emergence control of broadleaf and grass weeds in maize. Two field experiments were conducted in northern Greece in 2008 and 2009 to determine the response of grain maize to topramezone applied with the adjuvant DASH at 2–4, 4–6 and 6–8 maize leaf stage. In both years, plant height, cob number and yield were not differently affected with the use of herbicide at these growth stages, indicating no difference in selectivity and a similar response of maize to the three post-emergence applications of topramezone. Slight injury symptoms of leaf bleaching were observed in the second year, however, they were transient with no lasting injury on maize growth. 相似文献
24.
Georgios Michailidis 《Veterinary research communications》2010,34(5):459-471
In recent years host antimicrobial peptides and proteins have been recognised as key mediators of the innate immune response
in many vertebrate species, providing the first line of defense against potential pathogens. In chickens a number of cationic
antimicrobial peptides have been recently identified. However, although these peptides have been studied extensively in the
avian gastrointestinal tract, little is known about their function in the chicken reproductive organs and embryos. Chicken
Liver Expressed Antimicrobial Peptide-2 (cLEAP-2) has been previously reported to function in protecting birds against microbial
attack. The aim of this study was to investigate the expression of cLEAP-2 gene in the chicken reproductive organs, as well
as in chicken embryos during embryonic development, and to determine whether cLEAP-2 expression in the chicken reproductive
organs was constitutive or induced as a response to Salmonella enteritidis infection. RNA was extracted from ovary, oviduct, testis and epididymis of sexually mature healthy and Salmonella infected birds, as well as from chicken embryos until day ten of embryonic development. Expression analysis data revealed
that cLEAP-2 was expressed in the chicken ovary, testis and epididymis as well as in embryos during early embryonic development.
Quantitative real-time PCR analysis revealed that cLEAP-2 expression was constitutive in the chicken epididymis, but was significantly
up regulated in the chicken gonads, following Salmonella infection. In addition, expression of cLEAP-2 during chicken embryogenesis appeared to be developmentally regulated. These
data provide evidence to suggest a key role of cLEAP-2 in the protection of the chicken reproductive organs and the developing
embryos from Salmonella colonization. 相似文献
25.
Stylianos Liodakis Charalampos Michalopoulos Elpida Efthymiou Georgios Katsigiannis 《Water, air, and soil pollution》2012,223(1):169-179
One of the main environmental impacts of concentrated animal feeding operations is the soil degradation in vicinity with the
livestock breeding facilities due to substances such as ammonia emitted from the various stages of the process. Owing to the
high temperatures of the Mediterranean ecosystems, the evolution of gasses is more extensive and the soil degradation is consequently
more severe than those obtained in northern Europe. In this research, the soil degradation effects of a large meat-producing,
processing, and packaging unit have been investigated. The investigated intensive hog farming operation (IHFO) is located
at a limestone soil coastal area with sea to the north and hills to the south. Soil samples of the upper mineral soil were
taken in various distances and directions from the IHFO boundaries. Thirteen experimental cycles were carried out in the duration
of 1.5 years starting in March 2009 until October 2010. The soil samples were analyzed on pH and electrical conductivity (EC)
values as well as NH4
+ and NO3
− concentrations. Significantly higher concentrations of the two nitrogen forms were observed on samples at increasing proximity
downwind from the farm (south). Southern soil average NH4
+ and NO3
− concentrations ranged between 0.4–118 μg NH4
+-N g−1 soil and 6.1–88.4 μg NO3
−-N g−1 soil, respectively. The variation of emitted gasses depositions was clearly reflected in the average pH and EC values. Average
pH and EC values downwind from IHFO boundaries varied between 7.1–8.2 and 140–268 μS/cm, respectively. 相似文献
26.
27.
Kafas P Kafas G Manafis K Stavrianos C 《Pakistan journal of biological sciences: PJBS》2008,11(3):493-495
Osteomyelitis as a medical term defining a specific type of infection may be classified in acute and chronic form. In our case an acute mandibular osteomyelitis is reported with evaluation of the clinical and histological examination. The biological course of the disease determined on that basis. The significance of this report focused on the early diagnosis and the possible need for bone biopsy. 相似文献
28.
Constantinos Sikalidis Anestis Filippidis Georgios Papastergios Nikolaos Kantiranis 《Water, air, and soil pollution》2012,223(9):5637-5641
Over the last decades, removal of potentially toxic and hazardous materials has received a great deal of attention in the field of environmental pollution. Problems associated with the disposal of the wastes of different kinds of industries led to studies of the sorption?Cuptake properties of clay minerals and zeolites. In the present research, the behavior of vermiculite particles ranging between 425 and 500???m in a laboratory-scale fluidized bed column for uptake of Cs, Hg, and Mn ions from aqueous solutions and wastes in the presence of competing cations has been studied in order to investigate techniques for decontamination of liquid phases. Vermiculite selectively removed high percentages of Cs even from low concentrations in the presence of competing cations. Also removed were up to 60?% of added Hg2+ at concentrations of 5?ppm from drinking water and about 84?% from seawater, and furthermore, Mn2+ was selectively removed from low-concentration (ca 10?ppm) industrial wastes even when the ratio of Mn2+ to competing cations was 1:94. The results suggest the potential use of vermiculite as decontaminating agent in well-designed fluidized bed columns. 相似文献
29.
Deficit irrigation based on drought tolerance and root signalling in potatoes and tomatoes 总被引:1,自引:0,他引:1
Christian R. Jensen Adriano Battilani Georgios Psarras Franciszek Janowiak Zorica Jovanovic Xuebin Qi Sven-Erik Jacobsen 《Agricultural Water Management》2010,98(3):403-384
Agriculture is a big consumer of fresh water in competition with other sectors of the society. Within the EU-project SAFIR new water-saving irrigation strategies were developed based on pot, semi-field and field experiments with potatoes (Solanum tuberosum L.), fresh tomatoes (Lycopersicon esculentum Mill.) and processing tomatoes as model plants. From the pot and semi-field experiments an ABA production model was developed for potatoes to optimize the ABA signalling; this was obtained by modelling the optimal level of soil drying for ABA production before re-irrigation in a crop growth model. The field irrigation guidelines were developed under temperate (Denmark), Mediterranean (Greece, Italy) and continental (Serbia, China) climatic conditions during summer. The field investigations on processing tomatoes were undertaken only in the Po valley (North Italy) on fine, textured soil. The investigations from several studies showed that gradual soil drying imposed by deficit irrigation (DI) or partial root zone drying irrigation (PRD) induced hydraulic and chemical signals from the root system resulting in partial stomatal closure, an increase in photosynthetic water use efficiency, and a slight reduction in top vegetative growth. Further PRD increased N-mineralization significantly beyond that from DI, causing a stay-green effect late in the growing season. In field potato and tomato experiments the water-saving irrigation strategies DI and PRD were able to save about 20-30% of the water used in fully irrigated plants. PRD increased marketable yield in potatoes significantly by 15% due to improved tuber size distribution. PRD increased antioxidant content significantly by approximately 10% in both potatoes and fresh tomatoes. Under a high temperature regime, full irrigation (FI) should be undertaken, as was clear from field observations in tomatoes. For tomatoes full irrigation should be undertaken for cooling effects when the night/day average temperature >26.5 °C or when air temperature >40 °C to avoid flower-dropping. The temperature threshold for potatoes is not clear. From three-year field drip irrigation experiments we found that under the establishment phase, both potatoes and tomatoes should be fully irrigated; however, during the later phases deficit irrigation might be applied as outlined below without causing significant yield reduction:
- •
- Potatoes
- °
- After the end of tuber initiation, DI or PRD is applied at 70% of FI. During the last 14 days of the growth period, DI or PRD is applied at 50% of FI.
- •
- Fresh tomatoes
- °
- From the moment the 1st truce is developed, DI is applied at 85-80% of FI for two weeks. In the middle period, DI or PRD is applied at 70% of FI. During the last 14 days of the growth period, DI or PRD is applied at 50% of FI.
- •
- Processing tomatoes
- °
- From transplanting to fruit setting at 4th-5th cluster, the PRD and DI threshold for re-irrigation is when the plant-available soil water content (ASWC) equals 0.7 (soil water potential, Ψsoil = −90 kPa). During the late fruit development/ripening stage, 10% of red fruits, the threshold for re-irrigation for DI is when ASWC = 0.5 (Ψsoil = −185 kPa) and for PRD when ASWC (dry side) = 0.4 (Ψsoil, dry side = −270 kPa).
30.
Blagoja Boshkovski Constantinos Tzerakis Georgios Doupis Anhelina Zapolska Chariton Kalaitzidis 《Communications in Soil Science and Plant Analysis》2020,51(5):675-686
ABSTRACTSalinity and drought stresses are critical for Phaseolus vulgaris L. growth and development. They affect plants in various ways, including tissue mineral element content. Micro- and macro-elements in leaves of Phaseolus vulgaris L. (cv. ‘Blue lake’ and cv. ‘Terli’) subjected to deficit irrigation and salinity treatments were investigated, both analytically and with regards to their effect on the leaves’ spectral reflectance. B (boron), K (potassium), Mn (manganese), Na (sodium), Si (silicon) and Zn (zinc) appeared to be influenced by stress factors, mainly responding to salinity increase. The leaf spectral reflectance of the plants appeared to be significantly correlated with most of the elements under investigation. Multivariate regression identified a relationship of the reflectance at particular regions of the spectrum with phosphorus and NDVI (normalized difference vegetation index) and indicated a significant correlation with B, Fe (iron), K, Mn, P (phosphorus) and Zn. Moreover, customized spectral indices, exhibiting significantly high correlation with B, Fe, K, Mg (magnesium), Mn, Na, P, Zn and N (nitrogen), were developed. 相似文献