Influence of nitric oxide and reactive oxygen species on development of lettuce downy mildew in <Emphasis Type="Italic">Lactuca</Emphasis> spp.

The role of nitric oxide and reactive oxygen species, molecules indispensable for plant-pathogen signalling, was studied in the Lactuca spp.-Bremia lactucae pathosystem. Using a leaf disc model the translaminar effect of various compounds affecting their metabolism was studied by light microscopy. Time course studies revealed a slowdown in the development of B. lactucae (race BL16) infection structures by rutin (scavenger of reactive nitrogen and oxygen species) and SNP (NO donor) within 48 h post inoculation, followed by a retardation of sporulation. Application of the specific NO scavenger, PTIO, accelerated penetration of B. lactucae but had no further effects on the plant-pathogen interaction. Inhibitors of NO synthase (L-NAME) and nitrate reductase (sodium tungstate) did not influence pathogen development. Our results suggest that drastic change in the NO: hydrogen peroxide ratio seems to determine the pathogen’s fate. NO synthase-like activity significantly increased early after B. lactucae challenge in resistant L. virosa. Confocal laser scanning microscopy revealed the accumulation of nitric oxide in the penetrated cells, pointing to a role in the initiation of the hypersensitive reaction. The tips of germ tubes and appressoria of B. lactucae also accumulated NO, suggesting an essential role for this molecule in penetration of the biotrophic pathogen. Additionally, temporal changes in endogenous levels of rutin and quercetin in extracts from Lactuca spp. leaves will be discussed in connection to their role as part of the antioxidative machinery that influences the plants’ susceptibility/resistance to lettuce downy mildew.     

A comparative study of above- and below-ground parameters of healthy and declining young Norway spruce trees in a mountain area affected by air pollution

The aim of this study was to characterize possible connections between above- and below-ground parameters and the decline of Norway spruce trees in the Jeseníky Mountains of the Czech Republic – an area affected both by long-term air pollution and subjected to liming. A part of this study was dedicated to soil analysis, which showed considerable changes in the soil environment and highlighted particularly high concentrations of magnesium and calcium, exceeding optimal limits by as much as 8 and 13 times, respectively. Our results suggest that the decline of evaluated trees is primarily connected to root system development, as we found no differences between evaluated above-ground parameters for either healthy or declining trees. Tree decline related directly to low numbers of skeletal roots, root origin and higher maximal angles between skeletal roots. Declining trees had on average five skeletal roots with maximal angles between them of 173^o, indicating poor mechanical stability. Regardless of tree vitality, 93% of all examined root systems were restricted to upper humus horizons with an average rooting depth of 10.2?cm. All evaluated trees showed severe root deformation into tangle, which suggests crucial influence of artificial planting on the architectural development of root systems.     

CNP Ratio and Dose Regulated Production of Water Chestnut <Emphasis Type="Italic">Trapa</Emphasis>: Social and Environmental Implications

Water chest nut Trapa is a minor fruit crop and potential carbon sequester of atmospheric carbon. Mass production of water chest nut using a vast number of unused small water bodies and derelict waters is a win-win-win-win strategy toward mitigation of global warming, nutritional security, empowerment and resource utilization. Growth performance of Trapa was conducted in small culture units using different CNP ratios (25:02:01; 101:08:01; 290:01:01) at a fixed dose (0.2 kg/tank) of mixed manure with different doses (100, 200, 400, 600 g) of optimal CNP ratio (101:08:01) during the life cycle of Trapa. The total number of fruits and the wet weight of Trapa in different dose treatments ranged from 56 to 192 and from 258 to 379 g/tank. Yield of Trapa remained maximum when CNP ratio was 101:8:1 at 200 g/tank and the dosage was 200 g/tank with the optimal CNP ratio (134 g) and then declined with further rise in fertilizer dose. The proximate analysis of Trapa revealed the highest phosphorus content in all the tissues (fruit, leaf, and root) of Trapa grown in the CNP ratio of 101:08:01. Of the total amount of carbon in Trapa, contribution was maximum by the fruit (38–41%), followed by leaf (27–35%) and root (23–32%) in different ratio treatment. The C content of harvested Trapa grown in different CNP ratios (Table 4) was higher in fruit (38–41%) followed by leaf (27–35%) and root (23–32%) among tissues. The amount of C observed in control (32%) increased by 6% in 25:02:01 (34%) which was higher than remaining two treatments (31%). Dry weight or total carbon content of water chestnut tended to rise with increasing levels of phosphate of water from the dosage of 100 to 200 g with optimal CNP ratio and declined thereafter. A direct relationship between the dry weight or carbon content of Trapa and the total carbon content or phosphate to total carbon ratio of water was established. However, the carbon content remained between 27–32% in all the three tissues of Trapa culture when cultured in different dose treatments. It is reasonable to conclude that water chestnut may be promoted for mass cultivation using the recommended culture protocol that would help trapping atmospheric carbon, provide nutritional security and employment generation and resource utilization.     

Farmers’ markets in Prague: a new challenge within the urban shoppingscape

Farmers’ markets are a relatively recent phenomenon in Prague, Czechia. The first of them was opened in the autumn of 2009, but the real boom started in the spring/summer of 2010. The survey introduced in this paper is concerned with the study of alternative food networks and farmers’ markets. It offers the results of methodological triangulation based on: (1) the data obtained via the questionnaire survey, (2) market organizers’ reflections on the customer structure, motivation for shopping at farmers’ markets and the question of social exclusivity of farmers’ markets in Prague as revealed in interviews, and (3) the field notes from the participant observation at the markets under study. The results show that farmers’ markets are emerging all around Prague in localities of different social status, so the poorer citizens are not necessarily excluded from the access to markets. The differences between markets, in terms of size, range of goods, and term seem to follow the inner city/hinterlands divide rather than the socio-spatial differentiation of the city. New consumer patterns clearly result from the cultural environment, specific context, and also from the different development path of the post-socialist consumer society.     

Czech traditional agroforestry: historic accounts and current status

Agroforestry in the Czech Republic has vanished both from the landscape and public conscience. That raises questions about its history and fate; there are examples of this land use type from all neighbouring countries. The article looks at the record of such systems in a historical land tax survey, the Franciscan cadastre made in the Czech Republic in the mid nineteenth century. With this source, patterns of preindustrial-era subsistence systems were analysed in a considerable part of what is now the Czech Republic. Any correlation among occurrences of various land uses (including agroforestry cultures) and influences of chosen natural and cultural factors was statistically tested and further visualised by multivariate analysis. The main existing agroforestry types and their historical distribution were investigated. The results have shown that cropland with fruit trees, and meadows, and pastures with either fruit trees or wood use, were a common part of Czech countryside in the mid-nineteenth century. Some agroforestry plots were found in the 1689 total studied cadastral areas. The types of agroforestry and the overall subsistence patterns were attuned to elevation, soil fertility, population density, and the dominant language group of the inhabitants. Cropland and pastures with fruit trees were associated with more fertile inland lowlands with sound infrastructure and prevalently Czech inhabitants (so-called ‘old settlement’ areas), wood meadows and pastures with cadastral units located in border regions at higher elevations characterised by lower soil fertility, a greater ratio of coniferous forests and predominantly inhabited by Czech Germans. Traditional agroforestry, as is discussed, however, did not survive the industrialisation of agriculture.     

Size, shape and surface morphology of starch granules from Norway spruce needles revealed by transmission electron microscopy and atomic force microscopy: effects of elevated CO(2) concentration

We compared the effects of ambient (350 ppm) and elevated CO(2) concentration (700 ppm) on the size and shape of starch granules in Norway spruce (Picea abies (L.) Karst.) needles during one growing season. Starch granules were isolated from needles by alkaline digestion and analyzed by transmission electron microscopy (TEM) and atomic force microscopy (AFM). Measurements made with a particle size analyzer indicated that starch granules ranged between 0.5 and 10 microm. Granule size and shape varied according to needle developmental stage and CO(2) concentration. Generally, elevated CO(2) concentration increased the size of the starch granules. Fine surface structures (< 10 nm in size) studied by AFM were characterized by the presence of protrusions, furrows and pores.     

Stress responses of carp pond fish stock upon hunting activities of the great cormorant(Phalacrocorax carbo sinensis L.)

In addition to direct predation, cormorants can affect carp pond fish stock through disturbance and wounding of the fish. Fish stress response was evaluated by catch per unit effort (CPUE) using lift‐net sampling. A significantly higher (P<0.001) CPUE was recorded in the littoral region of ponds affected by cormorant visits (43.6 ± 39.6) in comparison with a control pond (CP) without their occurrence (0.9 ± 1.1). Stress indices, spleen somatic index (SSI) and Fulton's condition coefficient (FCC) were evaluated for fish subject to two stress factors, hunting cormorants (HC) and pond harvesting (PH), and compared with levels in fish from the CP. Both SSI and FCC decreased significantly (P<0.05) in PH and HC fish in comparison with the control group, while non‐significant differences were observed in both SSI and FCC indices among the HC and PH groups. Plasma biochemical indices (cortisol, glucose and lactate concentrations) were significantly higher (P<0.01) in the PH group as compared with the HC and CP groups. Concentrations in the HC and CP groups did not differ significantly. Total plasma protein levels were significantly higher (P<0.01) in HC fish compared with CP fish, but did not differ significantly from PH fish.     

Stable isotopes reveal the importance of terrestrially derived resources for the diet of the freshwater pearl mussel (Margaritifera margaritifera)

1. The freshwater pearl mussel (FPM) is among the most endangered freshwater species worldwide. The few remaining populations suffer from low recruitment rates and are subject to habitat fragmentation, pollution, siltation, decline or loss of host fish populations, and climate change.
2. Successful conservation strategies for FPM require a holistic understanding of its ecological requirements, life history, population dynamics, and habitat prerequisites. Although habitat requirements are well described, food requirements at different life stages have received less attention.
3. Stable isotope analyses of FPM and potential food resources in three German streams were combined with mixing model analysis to quantify organic matter resources assimilated by juvenile (first year after encystment from host fish) and semi-adult (10 years old, immature) individuals.
4. There were only slight differences in dietary contributions between the two life stages, and terrestrial particulate organic matter and benthic organic matter contributed substantially to the diet. Tissue type was more important in explaining variation in dietary contributions than individual variation for semi-adult FPM. The strong reliance on terrestrial resources sheds new light on the functional role of unionid mussels and the connection of streams to their riparian area.
5. The dependence of FPM on terrestrial resources also emphasizes the need for a stronger focus on the restoration and protection of intact riparian areas, including wetlands with their specific vegetation, when planning conservation and management strategies for threatened FPM populations.

     

Phytate degradation,intestinal microbiota,microbial metabolites and immune values are changed in growing pigs fed diets with varying calcium–phosphorus concentration and fermentable substrates

The present study assessed effects of diets containing varying calcium–phosphorus (CaP) concentration and fermentable substrates on digestibility of diets, intestinal microbiota and immune system using 32 crossbred pigs (initial BW 54.7 kg). In a 2 × 2 factorial arrangement, pigs were fed either a corn–soybean meal (CSB) or corn–field pea (CFP) diet with either low [‐] (4.4 g Ca/kg; 4.2 g total P/kg) or high [+] (8.3 g Ca/kg; 7.5 g total P/kg; supplemented with monocalcium phosphate) CaP content for a period of 9 weeks. In week 8, blood samples were taken, and at the end of the trial, all pigs were euthanized to collect digesta and mesenteric lymphoid tissue. Apparent total tract digestibility (ATTD) of P was greater (p < 0.05) for pigs fed the CaP+ and CFP diets than CaP‐ and CSB diets. The myo‐inositol 1,2,3,4,5,6‐hexakis (dihydrogen phosphate) (InsP₆) concentration in jejunal digesta was higher (p < 0.05) for CaP+ than in CaP‐ fed pigs. In addition, caecal and faecal InsP₅ isomer concentration were greater (p < 0.05) for CSB than CFP diets. In the caecum, gene copy numbers of saccharolytic bacteria, such as Eubacterium rectale and Roseburia spp., as well as SCFA concentration were higher (p < 0.05) for CaP+ than CaP‐ diets. In particular, innate immune cell numbers, such as natural killer cells, dendritic cells, monocytes and neutrophils, were greater (p < 0.05) for CaP+ than CaP‐ fed pigs. Diets high in CaP resulted in higher abundance of potential beneficial bacteria and might promote the first line of defence enhancing the activation of the cellular adaptive immune response, thereby possibly decreasing the risk for intestinal disturbances. These results strongly suggest that both, CaP supply and dietary ingredients differing in fermentability, may beneficially affect gut health through increase in SCFA‐producing bacteria and/or bacteria with anti‐inflammatory properties.