Abstract

This study was conducted to investigate the effect of salinity on germination rate of stinkwort ( Dittrichia graveolens (L.) Greuter) and false yellowhead ( D. viscosa (L.) Greuter). Lettuce ( Lactuca sativa L.) was used as a positive control. Seeds of all three test species were sown on agar plates with three different NaCl treatments (2.5 g NaCl/L ≈ 42 mM NaCl, 5 g NaCl/L ≈ 85 mM NaCl and 10 g NaCl/L ≈ 171 mM NaCl) and control treatment without NaCl. The three tested species germinated under all salinity conditions. However, they thrived best under control conditions and their germination rate was gradually declining with increasing salinity. Additionally, the start of their germination was delayed with increasing NaCl concentration. According to our findings, we can conclude that both Dittrichia species are very tolerant to salinity.

Keywords

salinity, germination rate, tolerance, Dittrichia graveolens , stinkwort, Dittrichia viscosa , false yellowhead, Lactuca sativa , lettuce

Abstract

Japanese knotweed ( Fallopia japonica ) is one of the most invasive of

species in Europe, and can substantially reduce local native biodiversity. In the present

study, the allelopathic potential of crack willow ( Salix fragilis ) on growth of Japanese

knotweed was investigated. Aqueous extracts of 0.1% and 1% (w/v) were prepared

from liophilised willow leaves and used for watering of young knotweed plants. Their

growth was monitored for 196 days. Shoot height and leaf number were not affected

but the mass of leaves and especially roots was reduced (up to 32%). At the end of

experiment, biochemical characteristics related to physiological state (photochemical

efficiency of PSII, protein content, enzyme activity of guaiacol peroxidase, lipid

peroxidation) were measured. Mostly, they were at control levels, but the activity of

guaiacol peroxidase and lipid peroxidation in roots increased. The extracts of crack

willow showed moderate inhibitory effect on roots of treated knotweeds while the

growth of shoots was unaffected. Given the root reduction described here, further

studies with willow extracts and field studies with crack willow and Japanese knotweed

plants would be reasonable.

Keywords

Fallopia japonica, Salix fragilis, invasive species, leaf extract, allelopathy, growth

Abstract

Alpine dock ( Rumex alpinus ) is a troublesome weed particularly in protected zones or Natura 2000 areas, in which only non-chemical control measures can be applied. The aim of our study was to investigate by means of a field experiment the effectiveness of various non-chemical methods: mowing, manual removal, heating, foil and grazing by cattle and pigs. Floristic changes, cover, number of shoots and biomass were monitored at 14-day intervals for three consecutive years. Manual removal and foil were most successful, with almost complete removal of the biomass and cover of alpine dock, and mowing, which reduced the cover to 50%. Other methods were not as efficient. Animals avoid grazing on R. alpinus and heat merely supresses dock growth for a short period.

Keywords

Slovenia, mountain pastures, agricultural management strategies, weed control, Rumex alpinus

Abstract

Despite the anticipated environmental release of anthropogenic gold

nanoparticles (AuNPs), there is currently not enough data on their potential impact on

terrestrial environment. In the current study, we investigated the effects of considerably

low concentrations of AuNPs on terrestrial isopods ( Porcellio scaber ) after 14 days of

exposure. The effects on mortality, weight change, feeding rate, avoidance/preference

feeding behavior, and cell membrane destabilization of digestive gland cells were

followed. In parallel, the accumulation of Au in the digestive glands was measured.

Our results show that none of the tested parameters was affected in isopods under

given exposure doses (10 and 60 μg Au/g dry leaf) and exposure duration. No Au was

assimilated in the digestive glands. Also, the same doses of the reference chemical,

AuCl 3 , showed no effect. We conclude that these concentrations of AuNPs are safe for

terrestrial isopods. We encourage reporting the results showing no adverse effects of

nanoparticles to balance the prevailing publication of their adverse effects. This will

help to build a realistic public perception of the environmental risk of nanomaterials.

Keywords

nanoparticles, Au , avoidance behavior, bioaccumulation, safety

Abstract

Honeybees ( Apis mellifera ) are important pollinators threatened by

environmental pollution, plan protection products and other potential contaminants.

Due to an extensive predicted use of engineered nanomaterials (NMs) in agriculture

the impact on honeybees should be investigated. We studied the 10-days chronic

dietary effect of carbon black (CB) and titanium dioxide (TiO 2 ) NMs on the antioxidant

activities, cholinergic function, feeding behaviour and survival of honeybees.

Exposure of honeybees Apis mellifera carnica to TiO 2 and CB NMs (1 mg ml -1 ) did

not affect the feeding and survival. No alteration of catalase, acetylcholinesterase and

glutathione S-transferase enzymatic activity was noticed in the brain of honeybees,

indicating that TiO 2 and CB NMs at the tested exposure dose had no adverse effects

on honeybees. Currently predicted environmental concentrations for TiO 2 and CB

NMs are significantly lower than the concentration tested in the current study. Based

on our findings we conclude that the potential use of TiO 2 and CB NMs in agriculture

is currently safe for honeybees at the tested concentration level and presents potential

advantages compared to other NMs with known toxic potential.

Keywords

nanopesticide, carbon black nanomaterial, titanium dioxide nanomaterial, acetylcholinesterase, glutathione S-transferase, catalase, feeding behaviour.

Abstract

In the skeletons of four grey herons ( Ardea cinerea ), we studied the

morphological characteristics of bones and skeletal groups, particularly certain

segments of the skull, spine, pectoral girdle, sternum and pelvic girdle. The skull is

characterized by a pronounced craniofacial bending zone ( zona flexoria craniofacia lis ),

long frontal bone ( os frontale ) with a distinct longitudinal depression ( depressio

frontalis ), long postorbital arch ( arcus postorbitalis ), extensive temporal fossa ( fossa

temporalis ) and additional shallow subtemporal fossa ( fossa subtemporalis ). The

parasphenoid rostrum ( rostrum parasphenoidale ) is distinctive, pterygoids ( ossa

pterygoidea ) are strong and straight. Cervical vertebrae are characterized by stronger

calcification of the sixth vertebra and its rigid link to the fifth. At the notarium region

vertebrae are not fused: a joint is clearly seen between the last cervical and first

thoracic vertebrae. The first three thoracic vertebrae are not fused, however, they are

tightly connected at the ventral section. The fifth dorsal vertebra is associated with

the synsacrum. The clavicles are fused into the fork ( furcula ) and their apophysis

forms a synostosis with the top of the sternal keel ( apex carinae ). Coracoids end at

the sternum, each in its own groove ( sulcus articularis coracoideus ), in a way that the

sternal end of the right coracoid is placed slightly over the left. On the handle of the

sternum ( manubrium s. rostrum sterni ) an internal thorn ( spina interna ) is missing,

with a short groove in its place. The basic morphological description is complemented

by images of bones or the skeleton, and two X-ray images of a live animal. Presented

are also the measurements of individual bones.

Keywords

anatomy, skeleton, birds, Ardea cinerea

Abstract

Cyanobacterial blooms in fresh water bodies have a serious negative

impact on human, animal and environmental health. The impact of electro-oxidation

of water containing Planktothrix rubescens in electrolytic cell equipped with diamond

electrodes has been tested. The treatment had an immediate effect on cyanobacterial

phycocyanin and chlorophyll fluorescence response and total cell biovolume. Cyanobacterial

number reduced for 80 % 130 h after a single treatment of 500 mL of a water

sample through electrolytic cell with a flow rate 1 L/min. Obtained results indicate a

great potential of the method for in-lake cyanobacterial control.

Keywords

Electrolytic cell, boron doped diamond electrode, cyanobacterial

bloom control, hydroxyl radicals