Chalcone synthase expression and pigments deposition in wheat with purple and blue colored caryopsis

Red and white caryopses are typical in common wheat. Genotypes with purple and blue caryopses are also described. This coloring is caused by anthocyanins which deposit in the pericarp (purple) or aleurone layer (blue). The anthocyanins biosynthetic pathway is well described. The key enzyme is chalcone synthase (CHS). It catalyzes the first step. We observed the deposition of anthocyanins in the pericarp and aleurone layer, the expression of a chalcone synthase gene and the amount of two anthocyanins - cyanidin-3-glycoside (pericarp of purple caryopses), and delphinidin-3-glycoside (aleurone layer of blue caryopses) during caryopsis development. Purple pigment deposition was not homogeneous and/or uniform. At first, small isolated spots of purple color were formed and thereafter they expanded. In blue caryopses, however, the coloring process was more homogeneous. The expression of chalcone synthase mRNA occurred five days before pigment deposition and finished earlier than expected. Amounts of cyanidin-3-glycoside and delphinidin-3-glycoside increased in a similar manner. Amounts of these fell at the end of caryopses development probably due to formation of more complex substances.     

Structure and diversity of small mammal communities of mountain forests in Western Carpathians

We sampled the small mammal (SM) community in mountain forest ecosystems of the Beskydy Mountains over 5 years in order to study associations with different types of forest habitat. Fourteen species were determined, three being eudominant (yellow-necked mouse—Apodemus flavicollis (45 %), bank vole—Clethrionomys glareolus (23.3 %) and field vole—Microtus agrestis (15.7 %) and one dominant common shrew—Sorex araneus (9.3 %)). Highest abundance was observed in young succession sites (plantations) with dicotyledonous plants dominant (>50 %) in the undergrowth. Highest diversity was observed in plantations and primeval forests. Lowest total abundance and diversity were observed in mature monocultures. Significant differences in diversity were only found between old monocultures and other sites. Using a faunistic similarity index, two basic SM community groups were determined: those inhabiting (1) early (plantation) and late (reserve) successional forest ecosystems with a dense dicotyledonous plant herb layer, and (2) plantations with a dense grass herb layer and forests with a dense canopy closure (fruiting monoculture). Redundancy analysis confirmed separate habitat preferences of the three eudominant species. Generalised linear model indicated increasing preference of field vole for plantations with dominance of grass and <10–15 % admixed dicotyledonous plants while decreasing preference at ratios >10–15 %, and increasing preference of bank vole for plantations with a dicotyledonous plant ratio of >10–15 %. The biotopes monitored proved suitable for long-term survival of the dominant SM species. Early successional plantations and forest reserves also represent important refuges for a number of rarer SM species presently under threat.     

A river runs through it: Land-use and the composition of vegetation along a riparian corridor in the Cape Floristic Region, South Africa

Riparian zones are important for the many ecosystem services they supply. In settled areas, the vegetation of such zones is shaped by human land-use; this often creates conditions under which alien plant species thrive. Alien plants have been shown to induce large-scale changes in riparian habitats, and they pose a major threat to the continued provision of key ecosystem services. We used direct gradient analysis to assess correlations between land-use and the composition of vegetation along a riparian river corridor in the highly transformed landscape surrounding Stellenbosch in South Africa’s Western Cape Province. Vegetation plots were sampled along the entire length of the river from headwaters to estuary (ca. 40 km). Plant community composition was analyzed in relation to land-use data collected in the field, and additional land-use variables computed from digital land-cover data. Patterns of plant community structure were found to be directly related to land-use, with measures of cover, richness, and diversity differing significantly among land-use types. Portions of the riparian zone adjacent to agricultural land had the greatest level of alien plant cover, while areas bordered by urban land maintained the highest alien species richness. Areas adjacent to grazing and natural lands showed intermediate and low levels of invasion, respectively. Several native species were found to persist in areas with high abundance and diversity of invasive alien plants, suggesting that they will be valuable focal species for future restoration attempts. Due to the level of human-mediated change in many areas of the riparian zone, restoration to historic conditions over most of the river is not considered feasible. These areas should be recognized as examples of novel ecosystems, and management efforts should focus on restoring or creating desirable ecosystem functions, rather than on achieving assemblages comprising only native species.     

Direct and indirect air pollution effects on materials including cultural monuments

Damage caused to materials exposed in the atmosphere constitutes one of the most important direct effects of acidifying air pollutants. Systematic field and laboratory investigations performed in the recent decade in many countries have contributed to a considerable increase in the knowledge on the mechanisms of the effects of pollutants, on the quantification of damage and on the assessment of the cost of damage. Beside the very important role of SO₂ for several materials also studies of the direct or synergistic effect of NO_x and O₃ have contributed to the understanding of the complex pollution effects. Even if there are still considerable gaps of knowledge it seems that NO_x and O₃ may contribute in an important way to the deterioration of several materials also in indoor environments which are important for i.a. electronic equipment, storage conditions and museums. Important knowledge has been gained from the International Cooperation Project within UK ECE which is an extensive field exposure on 39 test sites. Dose-response relations have been obtained after 4-year exposure showing the effect of dry and wet deposition on corrosion of several material groups. Also the effect of micro- and mesoclimate on corrosion of building materials like plaster and bricks in different positions on buildings and locations within an urban area has been subject to systematic studies. Results from the studies are used i.a. for assessment of so called acceptable corrosion levels and for mapping areas where the levels are exceeded at different pollution scenarios, as well as for calculation of economic damage. Based on model studies for some city areas tentative calculations of damage cost have been performed for the European region. The indirect effects consist of increased corrosion due to water and soil acidification which are of importance in geologically sensitive areas. Structures which are in contact with soil and water represent a very great capital investment and are of vital importance to the community.     

Volatile organic compounds in water and sediment from the Morava and the Danube Rivers (Slovakia) using purge and trap injection and gas chromatography

Purge and trap injector (PTI) with high resolution gas chromatography (HRGC) was used to determine the concentration levels of volatile organic compounds (VOCs) in water and sediments from the Morava and the Danube Rivers. Thus the average concentrations of volatile n-alkanes (C₆-C₁₃) in water and sediments were found to be 0.02—1.33 μg/l and 0.04–105 μg/kg wet weight respectively. While the average concentrations of volatile aromatics in water and sediments were found to be 0.07–3.62 μg/l and 0.08–290 μg/kg wet weight respectively. In general different concentration levels were found at different locations, and at different time periods. With PTI-HRGC small sample size (5–20 ml) of water and (10–20 g) of sediments were used to analyse the VOCs in a simple, rapid method, with low background contamination since the system is completely closed. Relatively higher concentrations of VOCs were found in water and sediment samples from the Morava in comparison with those from the Danube, and higher concentration levels were found in spring time than in summer time.     

Spatial variability of cadmium,pH, organic matter in soil and its dependence on sampling scales

Distribution of cadmium, pH _KCl , and organic carbon content in the soil over a 29-ha field was evaluated. Cadmium concentrations were found mostly within the interval 0.17–1.27 ppm, with increasing trend towards one edge of the field. Cadmium concentrations were correlated with pH and organic carbon content. A one-hectare section of the original area was selected to analyze spatial variability of cadmium, pH and organic carbon content using geostatistical techniques. Cadmium concentrations were found to be spatially dependent and anisotropic, whereas pH levels did not reveal space dependence. Similar spatial behaviour of cadmium and organic carbon was observed. Linear correlation analysis at the one-hectare section revealed strong correlation between organic carbon and Cd, whereas no coincidence between Cd and pH was found. Extensive application of a cadmium-contaminated sludge in the past is suggested as a possible cause of this phenomenon.     

Enzyme variation and pathogenicity of recent field isolates of Eimeria tenella

Seventy isolates of Eimeria tenella, obtained from commercial poultry farms worldwide and four reference laboratory strains were characterised by studies on the electrophoretic mobility of up to three enzymes. All populations possessed the same electrophoretic form of lactate dehydrogenase and malate dehydrogenase and one of two forms of glucose phosphate isomerase. One isolate was characterised by both forms of glucose phosphate isomerase. Studies on several isolates indicated that there was no correlation between the form of glucose phosphate isomerase found and the pathogenicity of an isolate.