Borivoj Krstić

THE POTENTIAL OF DIFFERENT PLANT SPECIES FOR NICKEL ACCUMULATION

ABSTRACT Contamination of the environment with toxic heavy metals is a mayor environmental problem. Aimed to find effective and economical attractive solutions for environment cleaning, scientists intensively evolve various phytoremediation techniques. Nickel is one of the essential micronutrients for plants, animals, and humans, but toxic at elevated concentrations. Also, it belongs to a group of heavy metals. In respect of the fact that Ni uptake relies upon plant species and that some of them show hyperaccumulation effects, the aim of our study was to analyse Ni concentration in certain plant species affected by Ni contamination of air and surface soil. Ni deposition in the air was below 60 μg/m2/month, while Ni content in the soil was between 42 and 150 μg/g. Average Ni content in plants ranged from 0.1 to 5.0 μg/g. Regardless the analysed locality, the highest Ni (7.1 μg/g) was obtained with the hogweed, whereas the lowest (4.5 μg/g) with the vines. Ambrosia artemisifolia and Taraxum officinale accumulated the greatest amounts of Ni (10.72 and 10.61 μg/g, respectively). It may be concluded that the analysed plant species exhibit various phytoremediation potential for Ni under the same ecological conditions.

Effect of Traffic on the Soil Contamination with Polycyclic Aromatic Hydrocarbons (PAHs)

ABSTRACT The level of the environment pollution with polycyclic aromatic hydrocarbons is mainly in correlation with degree of the region industrialization and the traffic density. The aim of this study was to determine the effect of exhaust gases of gasoline and diesel motors on the polycyclic aromatic hydrocarbons (PAHs) accumulation in the soil, along the main road M-21. Soil samples were collected from seven localities, at two depths (0–20 and 20–40 cm). The method used for PAHs determination was gas chromatography—mass spectrometry (GC-MS). The obtained results showed that PAH concentrations, mainly originating from diesel motors, were lower than 1 mg/kg soil. Concentrations of phenanthrene, benzo(a)anthracene and benzo(b)fluoranthene were elevated at all chosen localities and at depths of 0–40 cm.

HEAVY METALS IN THE LEAVES OF TREE SPECIES Paulownia elongata S.Y.Hu IN THE REGION OF THE CITY OF BELGRADE

ABSTRACT Based on the analysis of the heavy metal content (Zn, Fe, Pb, Cu, Ni, Cr, Mn, Cd, As, Hg) in leaves of the trees growing in the urban part of the city of Belgrade, wider city area and rural area it may be noted that the content of Fe, Pb, Ni, Cr and Cd increases going from rural to urban area. The obtained results may be related to the increased air pollution in urban and suburban areas where some of these heavy metals appear as a direct consequence of fuel combustion. The level of tolerance of the species Paulownia elongata S.Y.HU towards air pollution represents the basis for its development and survival in urban conditions as well as setting up of tree alleys and forming wind protection zones along main traffic lines.

Concentrations of manganese and iron in some woody and herbs plants

Heavy metals are the substances that indicate environmental pollution. The plants polluted with heavy metals may endanger natural environment and cause health problems in humans. In our multidisciplinary research of the concentrations of pollutants in forest ecosystems and natural environment in Belgrade, we examined the contents of heavy metals essential for plants but harmful in greater concentrations on a long-term basis. The fact that heavy metals manganese and iron are accumulated in plants to the greatest extent focused our work on determination of the level of concentrations of Mn and Fe in the vegetative parts of 8 plant types on three locations on the Avala Mountain and one location in the centre of the city of Belgrade. The analyses of heavy metals contents in plants were performed by the method of flame atomic absorption spectrophotometry. The examination of the existence of important differences between the average values was performed by implementation of Duncan’s test for the level of significance of 95%. The current contents of heavy metals in plants in the area of the protected natural resource Avala do not represent danger that would presently cause notable damage to forests but show the tendency of the increase of concentrations. Therefore, this issue should be constantly monitored.

Influence of Cd and Ni on Content of N, P, K, Nitrates and Activity of Nitrate Reductase in Clones of Salix Spp.

ABSTRACT Influence of excessive amounts of heavy metals to plant nutrients and metabolism of mineral elements is usually regarded as inhibiting. Results of this paper are only partially in correspondence with this hypothesis. Levels of investigated nutrients were determined in four willow clones exposed to two concentrations of Cd and Ni in water culture solutions (10−4 M and 10−5 M). Nitrogen and nitrate uptake was unaffected. Activity of nitrate reductase was significantly decreased only by Ni. Contents of K and P were highly dependent on genotype and level of applied heavy metals. Possible causes of these variations are discussed.

Genetic aspects of mineral nutrition of wheat. I: Concentrations of N, P, K, Ca, and Mg in leaves

Fifteen wheat cultivars differing in genetic origin but with almost the same growing season were investigated. Plants were grown in pots under greenhouse conditions. The investigations included the main stem only while the secondary stems were removed. The plant material to be analyzed was collected at earing, milk‐waxy, and full maturity stages. The concentrations of N, P, K, Ca, and Mg, were analyzed in 4 leaves (each separately). The results show that highly significant differences in nutrient concentration were obtained between the cultivars. Variation in elemental ranges depended on stage of plant development, leaf age, and the particular element under consideration.

Genetic variability of mineral elements concentration in pepper varieties (Capsicum annuum L.).

Pepper (Capsicum annuum L.) is one of the major members of the vegetable kingdom. The differences between the individual varieties in mineral nutrition and the uptake of mineral elements have provoked our interest for the investigations of their genotype specificity. The chemical composition of pepper leaves at flowering and at the end of the growing season was analyzed. On the average, the content of total ash was app. 22%, namely 19-20% (soluble) and 2-3% (insoluble) at both stages. The highest accumulation values were obtained with nitrogen, then potassium, calcium and phosphorus, whereas the lowest with sodium. The most remarkable genotypic differences were recorded at the end of the growing season. The results obtained clearly demonstrate the chemical heterogeneity of pepper varieties. This crop may be grown successfully only if specificity of its mineral nutrition is known.

Variability of acorn anatomical characteristics in Quercus robur L. genotypes

The aim of this study was to examine variability of acorn anatomical characteristics in seventeen Quercus robur L. genotypes. Acorns were collected in clonal seed orchard Banov Brod (Srem, Vojvodina, Serbia). Microscopic measurements were done for pericarp (total thickness, thickness of exocarp and mesocarp), seed coat (total thickness, thickness of outer epidermis, parenchyma, and inner epidermis), and embryo axis (diameter, thickness of cortical region, and diameter of stellar zone). Obtained results revealed certain divergence between genotypes. The thickness of pericarp varied from 418 to 559 mm (genotypes 20 and 22, respectively). On average, the participation of exocarp in the total thickness of pericarp was 36.3%, of mesocarp 61.0%, while of endocarp 2.6%. The thickness of seed coat for individual genotypes ranged from 71 mm (genotype 28) to 157 mm (genotype 38). In addition, anatomic parameters of embryo axis varied among studied genotypes. The lowest cortical zone thickness and stellar zone diameter were measured in genotype 40, while the highest values in genotype 33.

The Effect of Cultivar and Leaf Age on the Content of Photosynthetic Pigments in Wheat

The synthesis of photosynthetic pigments is genetically controled (1). The amount of pigment synthesied depends upon environmental conditions (2) and the ontogenetic development of the plant (3, 4). The ratios and stability of the pigments in photosynthetic tissue are also important in the photosynthetic production of organic matter and the total yield (1, 5). This paper shows the results obtained from the examination of the content of chlorophylls a and b, and total carotenoids present in 15 wheat cultivars which were grown in field conditions.

Influence of Mineral Nutrition on the Content of Photosynthetic Pigments in Various Wheat Cultivars

It is known that numerous abiotic and biotic factors influence the content of chlorophyll pigments. Among abiotic factors, the major role is given to the influence of light, while the influence of elements of mineral nutrition immediately follow. Therefore, up to now, great importance has been given to investigations which refer to the importance of individual elements of individual elements of mineral nutrition in the synthesis and content of chloroplast pigments (1, 2, 3, 4). Since the chlorophyll molecule contains nitrogen and magnesium in its structure, their influence is regarded as dominant on the content of chlorophyll. It is proved that certain elements have specific influence on the structure of chloroplasts too, and this certainlly conditions their influence on the content of pigments in them. Finally, it should be emphasized that the obtained results are,from time to time, contradictory which can be interpreted by unequal conditions under which experiments were performed, mainly the concentration of elements in the nutritive medium and the genetic specificity of the plant model, as well as their ontogenic development.