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11.
Species composition of arbuscular mycorrhizal fungi in two mountain meadows with differing management types and levels of plant biodiversity 总被引:1,自引:0,他引:1
Boris Börstler Carsten Renker Ansgar Kahmen François Buscot 《Biology and Fertility of Soils》2006,42(4):286-298
Species composition of arbuscular mycorrhizal fungi (AMF) was analysed in two differently managed mountain grasslands in Thuringia
(Germany). Arbuscular mycorrhizal fungi were studied in the roots of 18 dominant plant species from a total of 56 (32%). Additionally,
spores of AMF were isolated from soil samples. Arbuscular mycorrhizal fungi species composition was analysed based on 96 sequences
of the internal transcribed spacer of the nuclear ribosomal DNA, 72 originated from mycorrhizal roots, and 24 originated from
AMF spores. Phylogenetic analyses revealed a total of 19 AMF species representing all genera of the Glomeromycota except Scutellospora and Pacispora. Despite a different farming intensity, resulting in remarkable differences concerning their plant species diversity (27
against 43 plant species), the diversity of AMF was found to be similar with 11 species on the intensively farmed meadow and
ten species on the extensively farmed one. Nevertheless, species composition between both sites was clearly different. It
thus seems likely that the AMF species composition, but not necessarily the species number, is related to above ground plant
biodiversity in the system under study. 相似文献
12.
Faleiro L Miguel G Gomes S Costa L Venâncio F Teixeira A Figueiredo AC Barroso JG Pedro LG 《Journal of agricultural and food chemistry》2005,53(21):8162-8168
Antilisterial activities of Thymbra capitata and Origanum vulgare essential oils were tested against 41 strains of Listeria monocytogenes. The oil of T. capitata was mainly constituted by one component, carvacrol (79%), whereas for O. vulgare three components constituted 70% of the oil, namely, thymol (33%), gamma-terpinene (26%), and p-cymene (11%). T. capitata essential oil had a significantly higher antilisterial activity in comparison to O. vulgare oil and chloramphenicol. No significant differences in L. monocytogenes susceptibilities to the essential oils tested were registered. The minimum inhibitory concentration values of T. capitata essential oil and of carvacrol were quite similar, ranging between 0.05 and 0.2 microL/mL. Antioxidant activity was also tested, the essential oil of T. capitata showing significantly higher antioxidant activity than that of O. vulgare. Use of T. capitata and O. vulgare essential oils can constitute a powerful tool in the control of L. monocytogenes in food and other industries. 相似文献
13.
Oxidation of methane in the rhizosphere of rice plants 总被引:14,自引:0,他引:14
Oxidation of CH4 in the rhizosphere of rice plants was quantified using (1) methyl fluoride, a specific inhibitor of CH4 oxidation, and (2) measuring changes in plant-mediated CH4 emission after incubation under air, N2, or 40% O2. No significant rhizospheric CH4 oxidation was observed from rice plants in the ripening stage. CH4 emission from rice plants 1 week before panicle initiation increased by 40% if CH4 oxidation in the rhizosphere was blocked. The growth stage of the rice plant is an important factor determining the rhizospheric CH4 oxidation. Fluctuation of rhizospheric CH4 oxidation during the growing season may help to explain the observed seasonal CH4 emission patterns in field studies. Measurements from four rice varieties showed that one variety, Pokkali, had higher rhizospheric CH4 oxidation. This was probably because Pokkali was in an earlier growth stage than the other three varieties. Both in the early and in the late growth stages, incubation under N2 caused a much stronger CH4 flux than inhibition of CH4 oxidation alone. Apparently, N2 incubation not only blocked CH4 oxidation but also stimulated methanogenesis in the rhizosphere. Incubation under a higher O2 atmosphere (40% O2) than ambient air decreased the CH4 flux, suggesting that increasing the oxidation of the rice rhizosphere may help in reducing CH4 fluxes from rice agriculture. The O2 pressure in the rhizosphere is an important factor that reduces the plant-mediated CH4 flux. However, inhibition of methanogenesis in the rhizosphere may contribute more to CH4 flux reduction than rhizospheric CH4 oxidation. 相似文献
14.
15.
Stanislas Talaga Frédéric Petitclerc Jean-François Carrias Olivier Dézerald Céline Leroy Régis Céréghino Alain Dejean 《Landscape Ecology》2017,32(9):1805-1818
Context
Many aquatic communities are linked by the aerial dispersal of multiple, interacting species and are thus structured by processes occurring in both the aquatic and terrestrial compartments of the ecosystem.Objectives
To evaluate the environmental factors shaping the aquatic macroinvertebrate communities associated with tank bromeliads in an urban landscape.Methods
Thirty-two bromeliads were georeferenced to assess the spatial distribution of the aquatic meta-habitat in one city. The relative influence of the aquatic and terrestrial habitats on the structure of macroinvertebrate communities was analyzed at four spatial scales (radius = 10, 30, 50, and 70 m) using redundancy analyses.Results
We sorted 18,352 aquatic macroinvertebrates into 29 taxa. Water volume and the amount of organic matter explained a significant part of the taxa variance, regardless of spatial scale. The remaining variance was explained by the meta-habitat size (i.e., the water volume for all of the bromeliads within a given surface area), the distance to the nearest building at small scales, and the surface area of buildings plus ground cover at larger scales. At small scales, the meta-habitat size influenced the two most frequent mosquito species in opposite ways, suggesting spatial competition and coexistence. Greater vegetation cover favored the presence of a top predator.Conclusions
The size of the meta-habitat and urban landscape characteristics influence the structure of aquatic communities in tank bromeliads, including mosquito larval abundance. Modifications to this landscape will affect both the terrestrial and aquatic compartments of the urban ecosystem, offering prospects for mosquito management during urban planning.16.
Santana Pedro Henrique Lopes Burak Diego Lang Thiengo Cássio Carlette Peçanha Anderson Lopes Neves Mirna Aparecida Mendonça Eduardo de Sá 《Journal of Soils and Sediments》2020,20(11):4103-4110
Journal of Soils and Sediments - After the greatest environmental disaster in the history of Brazil and the deposition of the iron ore tailings in alluvial regions, the process of revegetation for... 相似文献
17.
Vernica da Silva Oliveira Meringela Miranda da Cruz Gabriela Suassuna Bezerra Natan Emanuell Sobral e Silva Fernando Henrique Andrade Nogueira Guilherme Maranho Chaves Jos Lamartine Soares Sobrinho Francisco Jaime Bezerra Mendona-Junior Bolívar Ponciano Goulart de Lima Damasceno Attilio Converti dley Antonini Neves de Lima 《Marine drugs》2022,20(2)
In this study, films of chitosan and 2-amino-4,5,6,7-tetrahydrobenzo[b]thiophene-3-carbonitrile (6CN), a 2-aminothiophene derivative with great pharmacological potential, were prepared as a system for a topical formulation. 6CN-chitosan films were characterized by physicochemical analyses, such as Fourier-transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), X-ray diffraction (XRD), and scanning electronic microscopy (SEM). Additionally, the antifungal potential of the films was evaluated in vitro against three species of Candida (C. albicans, C. tropicalis, and C. parapsilosis). The results of the FTIR and thermal analysis showed the incorporation of 6CN in the polymer matrix. In the diffractogram, the 6CN-chitosan films exhibited diffraction halos that were characteristic of amorphous structures, while the micrographs showed that 6CN particles were dispersed in the chitosan matrix, exhibiting pores and cracks on the film surface. In addition, the results of antifungal investigation demonstrated that 6CN-chitosan films were effective against Candida species showing potential for application as a new antifungal drug. 相似文献
18.
Marcela dos Santos Castro Maridelzira Betania Moraes David Evonnildo Costa Gonalves Andrei Santos Siqueira Rodrigo Rodrigues Virgulino Delia Cristina Figueira Aguiar 《Journal of veterinary science (Suw?n-si, Korea)》2022,23(2)
BackgroundCanine herpesvirus type 1 (CaHV-1) infects dogs and is associated with neonatal deaths and reproductive, ocular, neurological, and respiratory problems. In Brazil, reports of CaHV-1 have been restricted to the southeast and south regions, particularly in municipalities in the state of Rio Grande do Sul.ObjectivesTo assess the presence and variability of CaHV-1 in canine populations in the state of Pará, North Brazil.MethodsBiological samples from 159 dogs from 4 municipalities in the State of Pará were evaluated using polymerase chain reaction and phylogenetic analyses, with the target being the viral enzyme, thymidine kinase.ResultsCaHV-1 was detected in 13 dogs (8.2%), with 2 animals being from the municipality of Santa Bárbara do Pará, 8 from Algodoal Island, 2 from Salinópolis, and one from Capanema. The study sequences revealed 100% identity among themselves and 64% to 100% identity with the other nucleotide sequences from Australia, Brazil, United Kingdom, and United States, including 100% identity with the 2002 isolate from Australia. The 1996 isolate from France was grouped in a branch that was different from the sequence of this study.ConclusionsThis study presents the first molecular detection of CaHV-1 in dogs from the Amazon region in northern Brazil. The nucleotide identity between the strains and cytosine insertion in the sequences isolated in this study suggests at least 2 strains of CaHV-1 circulating in Brazil (Pará and BTU-1). 相似文献
19.
Net mineral requirements for growth of Saanen goat kids in early life are similar among genders 下载免费PDF全文
A. N. Mendonça C. J. Härter S. F. Souza D. Oliveira O. Boaventura Neto B. Biagioli K. T. Resende I. A. M. A. Teixeira 《Journal of animal physiology and animal nutrition》2017,101(1):113-120
The current mineral requirements for growing goat kids are based on sheep and cattle studies without differentiating between the stages of development or gender. The aims of this study were to determine the net requirements for growth of Ca, P, Mg, Na and K of Saanen goat kids during the initial stages of growth and to analyse the effect of gender on the net requirements for growth of these macrominerals. Eighteen female, 19 intact male and 10 castrated male Saanen goat kids were studied. The kids were selected applying a completely randomized design and slaughtered when their body weight (BW) reached approximately 5, 10 and 15 kg to determine the mineral requirements for growth at these stages. The net mineral requirements for growth were similar among genders. The goat kids had slightly increased net requirements of Ca, P and Mg for growth with increasing BW from 5 to 15 kg. The net requirements for growth of Ca, P, Mg, Na and K ranged from 9.61 to 9.67 g/kg of BW gain, 7.14 to 7.56 g/kg of BW gain, 0.34 to 0.37 g/kg of BW gain, 1.26 to 1.13 g/kg of BW gain, 1.88 to 1.82 g/kg of BW gain as the animals grew from 5 to 15 kg respectively. In conclusion, when formulating diets for Saanen goat kids in early growth stage mineral levels do not need to adjusted based on gender. 相似文献
20.