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61.
Mark Otieno Ben A. Woodcock Andrew Wilby Ioannis N. Vogiatzakis Alice L. Mauchline Mary W. Gikungu Simon G. Potts 《Biological conservation》2011,(10):2424-2431
Arthropods that have a direct impact on crop production (i.e. pests, natural enemies and pollinators) can be influenced by both local farm management and the context within which the fields occur in the wider landscape. However, the contributions and spatial scales at which these drivers operate and interact are not fully understood, particularly in the developing world. The impact of both local management and landscape context on insect pollinators and natural enemy communities and on their capacity to deliver related ecosystem services to an economically important tropical crop, pigeonpea was investigated. The study was conducted in nine paired farms across a gradient of increasing distance to semi-native vegetation in Kibwezi, Kenya. Results show that proximity of fields to semi-native habitats negatively affected pollinator and chewing insect abundance. Within fields, pesticide use was a key negative predictor of pollinator, pest and foliar active predator abundance. On the contrary, fertilizer application significantly enhanced pollinator and both chewing and sucking insect pest abundance. At a 1 km spatial scale of fields, there were significant negative effects of the number of semi-native habitat patches within fields dominated by mass flowering pigeonpea on pollinators abundance. For service provision, a significant decline in fruit set when insects were excluded from flowers was recorded. This study reveals the interconnections of pollinators, predators and pests with pigeonpea crop. For sustainable yields and to conserve high densities of both pollinators and predators of pests within pigeonpea landscapes, it is crucial to target the adoption of less disruptive farm management practices such as reducing pesticide and fertilizer inputs. 相似文献
62.
唐文渊 《国外畜牧学(猪与禽)》2002,(2)
NRC以前的工作总结了肥育猪氨基酸对于赖氨酸理想比率的实验证据并发表了该理想比率的析因估计值.本文则对1997年以后发表的资料进行总结,以图对肥育猪的理想氨基酸模式进行更新. 相似文献
63.
ABSTRACT While characterizing the agents involved in symptomatology of a variegated mint, Mentha x gracilis 'Variegata', a nursery plant with atypical symptoms was examined. This plant, unlike 'Variegata', did not exhibit yellow vein banding symptoms but instead had distorted and crinkled leaves. Molecular tests for the three viruses found in 'Variegata' clones failed to detect any of these viruses in the plant. Double-stranded RNA was extracted and cloned, disclosing the presence of two unknown viruses. One of the viruses was a novel member of the family Closteroviridae. The complete nucleotide sequence of the virus, designated as Mint virus 1, has been obtained. A detection test was developed, and revealed the presence of the virus in several other mint clones and species. Genomic regions from three additional isolates were examined to investigate the genetic diversity of the virus. Genome and phylogenetic analysis placed Mint virus 1 in the genus Closterovirus and transmission studies have identified the mint aphid, Ovatus crataegarius, as a vector for this new member of the genus Closterovirus. 相似文献
64.
Virginie Martin Ioannis Vouldoukis Javier Moreno David McGahie Sylvie Gueguen Anne-Marie Cuisinier 《Veterinary research》2014,45(1):69
Control of canine leishmaniasis is an important objective for the benefit of dogs living in or visiting endemic areas and for public health because of the zoonotic nature of this disease. Resistance or susceptibility to developing canine leishmaniasis after exposure to Leishmania infantum is primarily determined by the ability of the immune system to develop an appropriate Th1-dominated specific response to the parasite. For this reason there is a need for effective canine vaccines that can decrease the number of dogs developing progressive infections. In this study, we followed the impact of the LiESP/QA-21 canine vaccine (composed of excreted-secreted proteins of L. infantum and the QA-21 saponin adjuvant), recently launched commercially in Europe, on selected humoral and cellular immune parameters following an infectious intravenous challenge with L. infantum promastigotes administered one year after the primary vaccine course. We also followed parasitological parameters to determine the parasitological status of the challenged dogs. In contrast to controls, vaccinated dogs retained significantly stronger cell-mediated immune responses against the parasite despite a virulent challenge and had significantly lower mean parasite burdens at the end of the study, associated with a lower probability of developing active infections. These results confirm that the immune responses generated by vaccination with LiESP/QA-21 are still effective against an intravenous challenge one year after the primary vaccine course. 相似文献
65.
The kinetic profile of oxolinic acid in sharpsnout sea bream, Diplodus puntazzo (Cetti 1777) 总被引:1,自引:0,他引:1
George Rigos Athanasios E Tyrpenou Ioannis Nengas Maria Alexis & Gera M Troisi 《Aquaculture Research》2004,35(14):1299-1304
The pharmacokinetics of oxolinic acid (OA) were investigated after a single intra‐vascular injection (20 mg kg?1 fish) in sharpsnout sea bream (90 g), a promising new euryhaline species for Mediterranean fish farming. The distribution half‐life (t1/2α) and the elimination half‐life (t1/2β) of OA were calculated to be 0.4 and 10 h respectively. The apparent volume of distribution at steady‐state (Vd(ss)) and total clearance rate (CLT) of the drug were found to be 2.1 L kg and 0.2 L kg?1 h?1 respectively. The bioavailability (F%) of OA following oral administration (40 mg kg?1 fish) was estimated to be 15%. The results indicate a rapid distribution and elimination of the drug, moderate tissue penetration, but low absorption in sharpsnout sea bream. The kinetic profile of OA found in this species is comparable with that observed in another well‐known sparid, gilthead sea bream. 相似文献
66.
Ioannis V. Ganopoulos Konstantinos Kazantzis Ioannis Chatzicharisis Irene Karayiannis Athanasios S. Tsaftaris 《Euphytica》2011,181(2):237-251
It is important to couple phenotypic analysis with genetic diversity for germplasm conservation in gene bank collections.
The use of molecular markers supports the study of genetic marker-trait associations of biological and agronomic interest
on diverse genetic material. In this report, 19 Greek traditional sweet cherry cultivars and two international cultivars,
which were used as controls, were grown in Greece and characterized for 17 morpho-physiological traits, 15 simple sequence
repeat (SSR) loci and 10 inter simple sequence repeat (ISSR) markers. To our knowledge, this is the first report on molecular
genetic diversity studies in sweet cherry in Greece. Principal component analysis (PCA) of nine qualitative and eight quantitative
morphological parameters explain over 77.33% of total variability in the first five axes. The SSR markers yielded a combined
matching probability ratio (MPR) of 9.569 × e−12. The 15 SSR loci produced a total of 92 alleles. Ten ISSR primers generated
91 bands, with an average of 9.1 bands per primer. Expected heterozygosity (gene diversity) values of 15 SSR loci and 10 ISSR
markers averaged at 0.683 and 0.369, respectively. Based on stepwise multiple regression analysis (MRA), SSR alleles were
found associated with harvest time and fruit polar diameter. Furthermore, three ISSR markers were correlated with fruit harvest
and soluble solids and four ISSR markers were correlated with fruit skin color. Stepwise MRA identified six SSR alleles associated
with harvest time with a high correlation (P < 0.001), with linear associations with high F values. Hence, data analyzed by the use of MRA could be useful in marker-assisted breeding programs when no other genetic
information is available. 相似文献
67.
Ioannis K. Kalavrouziotis Eirini Kostakioti Prodromos H. Koukoulakis Aristotelis H. Papadopoulos Michalis Leotsinidis Eleni Sakazli 《Water, air, and soil pollution》2011,214(1-4):565-573
Two greenhouse pot experiments were conducted in Agrinion, Greece, using a randomized block design in four replications, respectively, as follows: The first one included five levels of treated municipal wastewater (TMWW), being used as an irrigation water source. The second one, five levels of applied Cl at a constant soil applied Cd level of 10.36?mg/kg soil, the plants being irrigated with fresh well water. The purpose of these experiments was to study the impact of the Cl ?? Cd interrelationship on planning TMWW reuse, for the irrigation of Brassica oleracea var. Capitata (cabbage) cv F1 Gloria, ehich was used as test plant, in both of these experiments. It was found that the TMWW Cl content, originating mainly from the procedure of wastewater chlorination, was synergistically interrelated with the toxic heavy metal Cd, increasing its soil availability and cabbage plant leaf uptake (edible plant part). As this increase is directly associated with the consumer??s health, it was suggested that the TMWW be subjected to dechlorination process or the disinfection be made by ozonation or UV, which do not include Cl. 相似文献
68.
Ioannis K. Kalavrouziotis 《Water, air, and soil pollution》2011,221(1-4):159-168
The present paper aims at planning the treated municipal wastewater reuse in fragile ecosystems of Messolonghion lagoon and Acheloos estuary, which are protected as a Natura wetland under the Ramsar Treaty. The need for environmental protection of the wetlands became necessary due to the continuing anthropogenic intervention, as well as to the climate changes that have been occurring in recent years. Relevant studies have shown that the lagoon of Messolonghion and Acheloos estuary are ecosystems that have been burdened by anthropogenic activities (pesticides, fertilizers, overexploitation of underground aquifers, intrusion and land use change), as well as by climatic changes (temperature, precipitation, sea level), which altogether have adversely affected the hydrodynamic and ecological balance of the entire ecosystem. The Messolonghion lagoon and Acheloos estuary are also the recipients of the wastewater processing plant effluents, operating locally, which have over-enriched the waters with macronutrients N, P and K, favouring eutrophication. The municipal wastewater reuse for crop irrigation grown in the protected area appears to be an environmentally acceptable solution for alleviating the natural water shortage, since it could save significant amounts of irrigation water as well as it could reduce the adverse effects of the treated effluents discharge into the aquatic ecosystem. This study describes the planning of the treated wastewater reuse in this ecologically sensitive area, on the basis of the geomorphologic and geotechnical characteristics, climatic factors, and crop irrigation water requirements grown in the area. 相似文献
69.
Eleni Fountoulaki Henry Morgane George Rigos Vasilaki Antigoni Eleni Mente John Sweetman Ioannis Nengas 《Aquaculture Research》2010,41(9):e208-e216
This study aimed to investigate the effect of increased zinc dietary levels on the growth performance, feed utilization, immune status and induced wound healing in European sea bass (Dicentrarchus labrax). Fish weighing 10 g were fed five diets containing organic zinc at 30, 70, 110 and 150 mg kg?1 diet and one inorganic zinc source (zinc oxide) at 150 mg kg?1 diet for a period of 12 weeks. No significant (P>0.05) differences were found in the growth performance parameters (final weight, specific growth rate), immunological indices tested (respiratory burst activity in whole blood) and the wound‐healing process. Zinc accumulation in the skin, vertebrae and liver increased significantly (P<0.01) with increased dietary zinc levels but not in muscle. The highest zinc concentrations were obtained in skin tissue, followed by vertebrae, liver and muscle tissue. Using the concentration of zinc in skin as a response criterion, broken‐line analysis showed that the supplementation of 148 mg organic Zn kg?1 diet seemed to be the optimum dietary zinc supplementation level for sea bass juveniles. 相似文献