Branka Pevalek-Kozlina

• University of Zagreb

Metals have a variety of negative outcomes on plants, essential components of any ecosystem. The effects of CdCl2 (5 μmol L-1), ZnCl2 (25 or 50 μmol L-1), and CuCl2 (2.5 or 5 μmol L-1) and combinations of CdCl2 with either ZnCl2 or CuCl2 on the growth, photosynthetic pigments, and photosystem II (PSII) efficiency of duckweed (Lemna minor L.) were i...

Basic slag, used in this study as a potential source of certain nutrients, is a byproduct of the production of steel in electric arc furnace (EAF). A pot experiment with two nutrient-poor substrates was conducted to investigate to compare the effect of EAF steel slag and fertilizers NPK + F e on growth and availability of specific nutrients to maiz...

The present study investigated the effects of salinity on the perennial species Centaurea ragusina L. interesting as a potential cash crop plant. Plants grown in culture conditions were subjected to increasing salt (0–600 mM NaCl) or mannitol (300 mM) treatments for two weeks. Effects of isoosmotic concentrations of NaCl (150 mM) and mannitol were...

In this investigation growth parameters and certain endpoints (pigment content, peroxidase activity, lipid peroxidation and alkaline comet assay) were used to detect the toxic and genotoxic effects of surface water samples on duckweed plants. The surface waters of different origin and pollutant burdens were collected monthly over a 3-month monitori...

Background and Purpose: It is known that osmotic stress may cause damage to cells by inducing active oxygen species production or by disrupting detoxification mechanisms. We hypothesize that increased activity of antioxidant enzymes in duckweed (Lemna minor L.) provides a mechanism of tolerance to osmotic stress. Material and Methods: Plants were s...

Background and Purpose: Centaurea ragusina L. is an endemic Croatian plant species adapted to life in arid and salt-affected environments. Esterase activity (EST) and isoesterase patterns of C. ragusina plants cultured in vitro under saline and osmotic conditions were determined with an aim to evaluate the potential value of esterase activity as a...

The present study aimed at investigating effects of zinc and aluminum (0.15 and 0.3 mM) in duckweed (Lemna minor L.) over a 15-day period. High bioaccumulation of both metals was accompanied by an increase in dry weight under higher metal treatments. Antioxidant response was observed under both metal stresses, with large increases in superoxide dis...

This study aimed at assessing the toxic effects of industrial effluents using duckweed (Lemna minor L.) plants as a test system. Growth inhibition test according to standardized protocol (ISO 20079) was performed. The suitability of the Comet assay (indicates DNA damage) and certain parameters such as peroxidase activity and lipid peroxidation leve...

Screening for mutagens in complex environmental mixtures, such as surface water or industrial wastewater, is gradually being accepted as a routine method in environmental monitoring programs. In the present work, the simplified Alliumcepa root assay was utilized to evaluate the possible cyto- and genotoxic effects of surface and wastewaters collect...

The present study aimed at investigating effects of zinc and aluminum (0.15 and 0.3mM) in duckweed (Lemna minor L.) over a 15-day period. High bioaccumulation of both metals was accompanied by an increase in dry weight under higher metal treatments. Antioxidant response was observed under both metal stresses, with large increases in superoxide dism...

The physiological effects of thallium(I)-acetate on the duckweed Lemna minor after 1-, 4-, 7- and 14-d exposure were analyzed. High bioaccumulation of Tl (221 mg kg−1 dry wt at 2.0 μM Tl-acetate) caused an inhibition of plant growth. After 14-d exposure, 0.2, 0.5, 1.0 and 2.0 μM Tl-acetate reduced the frond-number growth rate by 21.1%, 39.4%, 66% a...

In vitro propagated plants of Mammillaria gracilis Pfeiff. (Cactaceae) develop calli without any exogenous growth regulators. This habituated tissue spontaneously regenerates morphologically normal as well as hyperhydric shoots. In this study, a possible involvement of activated oxygen metabolism in habituation and hyperhydricity in in vitro propag...

Symbiotic associations are of a wide significance in evolution and biodiversity. Green hydra is a typical example of endosymbiosis. In its gastrodermal myoepithelial cells, it harbors individuals of unicellular green algae. Morphological characteristics of isolated algae determined by light and electron microscopy are presented. Cytological morphom...

The effects of exposure to radiofrequency electromagnetic fields (RF-EMFs) on seed germination, primary root growth as well as mitotic activity and mitotic aberrations in root meristematic cells were examined in Allium cepa L. cv. Srebrnjak Majski. Seeds were exposed for 2h to EMFs of 400 and 900MHz at field strengths of 10, 23, 41 and 120Vm(-1). T...

Although duckweed Lemna minor L. is a known accumulator of cadmium, detailed studies on its physiological and/or defense responses to this metal are still lacking. In this study, the effects of 10μM CdCl2 on Lemna minor were monitored after 6 and 12 days of treatment, while growth was estimated every 2 days. Cadmium treatment resulted in progressiv...

Thallium (Tl) is a metal of great toxicological concern because it is highly toxic to all living organisms through mechanisms that are yet poorly understood. Since Tl is accumulated by important crops, the present study aimed to analyze the biological effects induced by bioaccumulation of Tl in broad bean (Vicia faba L.) as well as the plant's anti...

Analysis of genotoxicity is of a great importance due to the pollution of the environment by genotoxicants including risk assessment evaluation. In this study the response of the Allium cepa and Lemna minor L. genetic material to the presence of potential cytotoxic and genotoxic substances in surface and wasterwater samples was monitored. Also the...

Natural senescence of maple (Acer pseudoplatanus L.) leaves was investigated. Three types of senescing leaves were used: green (G), yellow-green (YG) and yellow (Y) ones. Down regulation of photosynthetic performance was achieved due to significant degradation of total chlorophylls, decrease in maximum quantum yield of PSII (Fv/Fm) and relative ele...

Widespread use of radiofrequency radiation emitting devices increased the exposure to electromagnetic fields (EMFs) from 300 MHz to 300 GHz. Various biological effects of exposure to these fields have been documented so far, but very little work has been carried out on plants. The aim of the present work was to investigate the physiological respons...

The discharge of untreated electroplating wastewaters directly into the environment is a certain source of heavy metals in surface waters. Even though heavy metal discharge is regulated by environmental laws many small-scale electroplating facilities do not apply adequate protective measures. Electroplating wastewaters contain large amounts of vari...

Allium cepa seeds were exposed to 900 MHz EMF in GTEM cell at four different field strengths (10, 23, 41 and 120 Vm ^-1) for 2 h. The effect of longer exposure time (4 h) and modulation was also investigated. Germination rate and root length did not change significantly after EMF exposure. However, EMF at higher strengths (41 and 120 V m...

There is accumulating evidence that exposure to radio frequency electromagnetic fields (RF-EMF) from mobile telephones or their base station could have detrimental biological effects. Therefore, the possible cyto-and genotoxic effects after 4 hour exposure of tobacco shoots to 900 MHz EMF were studied. The levels of lipid peroxidation and oxidation...

Centaurea ragusina L. is a Croatian endemic plant species growing on cliffs above the Adriatic Sea, but there is no information about its physiological behavior or stress tolerance. To investigate the response of C. ragusina plants to salinity and drought, we have analysed soluble peroxidase (POD; EC 1.11.1.7) activity, anionic isoperoxidase patter...

Centaurea ragusina L. (Asteraceae), an endemic Croatian species developed xeromorphic characteristics which have arisen as a consequence of arid- and salt-affected environment. Cytogenetic effects of mannitol (300 mM) and different NaCl concentrations (150, 300, 450 and 600 mM) on root meristem cells of in vitro cultured C. ragusina were analysed a...

Increased use of radio and microwave frequencies requires investigations of their effects on living organisms. Duckweed (Lemna minor L.) has been commonly used as a model plant for environmental monitoring. In the present study, duckweed growth and peroxidase activity was evaluated after exposure in a Gigahertz Transversal Electromagnetic (GTEM) ce...

Centaurea ragusina L. (Asteraceae) is an endemic Croatian plant species, which developed xeromorphic characteristics as a consequence of its natural environment – vertical limestone cliffs above the Adriatic sea. Cytogenetic status of C. ragusina long-term culture (94th subculture) and C. ragusina seedlings was analysed and compared after 4 weeks o...

A procedure for rapid in vitro propagation of the rare, endangered, ornamental and medicinal plant Pulsatilla pratensis (L.) Miller ssp. nigricans (Störck) Zämelis (Ranunculaceae) is described. Sterilized seeds were germinated on media of different pH values containing full or half-strength Murashige and Skoog macronutrients (MS) or supplemented wi...

Background and Purpose: Centaurea ragusina L. is an endemic Croatian species morphologically well adapted to dry and sunny habitats. The effects of drought induced by 300 mM mannitol on relative plant growth rate, soluble peroxidase (POD) activity and isoperoxidase pattern in C. ragusina plants cultured in vitro were evaluated. Material and Methods...

Background and Purpose: Alyssum montanum L. subsp. pluscanescens (Raim. ex Baumgartner) Trpin (Brassicaceae) is a rare and endangered Croatian stenoendemic plant species growing near Smerovišće only (Samoborsko gorje, south-western Croatia). The aim of the study was to investigate A. montanum subsp. pluscanescens micropropagation possibility in ord...

Background and Purpose: Influence of culture ageing and different concentrations of 2,4-D and kinetin on morphogenetic and cytogenetic status of Allium commutatum callus tissue was investigated. Material and Methods: Callus tissue was derived from root-tips of in vitro grown A. commutatum plantlets and grown on MS medium with or without 2,4-D and k...

Micropropagation of Dianthus gigantheus D'Urv. ssp. croaticus (Borbás) Tutin, a Croatian neoendemic plant species, was investigated. Shoots from aseptically germinated seeds were used for culture initiation. The highest multiplication rate (3.3 shoots per explant) was achieved on basal MS medium containing 2.9 μM gibberellic acid and 0.5 μM 6-benzy...

Differentiation and morphogenetic potential of Allium commutatum Guss. callus tissue was investigated in five subcultures. Callus tissue was derived from root tips of in vitro grown seedlings and maintained on MS medium supplemented with 3% sucrose, 0.8% agar, 4.5 μM 2,4-D and 4.6 μM kinetin. Pieces of calli were subcultured on media with different...

The micropropagation possibility for Degenia velebitica (Deg.) Hay., a Croatian endemic plant species was investigate and Shoots originated from aseptically germinated seeds collected on natural habitats were used for culture initiation. The highest multiplication rate of Degenia velebitica shoots (5.2 shoots per explant) was achieved on half stren...

Callus tissue was induced on root tips of in vitro cultured seedlings of Allium commutation Guss. on MS medium supplemented with 3 % sucrose, 0.8 % agar, 4.5 μM 2,4-dichlorophenoxyacetic acid (2,4-D) and 4.6 μM kinetin. Pieces of developed calli were transferred to MS medium with different concentrations of 2,4-D (0.02, 0.05 and 0.1 μM) and kinetin...

Callus tissue was induced on root tips of in vitro cultured seedlings of Allium commutatum Guss. cultured on MS medium supplemented with 4.6 μM kinetin and 4.5 μM 2,4-dichlorophenoxyacetic acid (2,4-D). Developed calli were transferred to the same basal medium with addition of 1.0, 2.5 and 5.0 μM 2,4-D or without 2,4-D. After three weeks in culture...

Analysis of structural chromosome aberrations was performed in a group of radar station personnel who were engaged in repairing radar devices a couple of days earlier. Test results showed a major decline from the values recorded by regular mutagenic monitoring in terms of a significantly increased number of chromosome breaks, acentric fragments, di...