Abstract

The present work deals with the history of the Ljubljana Botanic Garden. It brings to light some newly discovered archive documents. It provides a closer examination and comparison of Paulin’s and Voss’s assessments of the Garden for the period after F. Hladnik (1834) till the arrival of A. Paulin (1886), which are further compared with the so far undisclosed archive documents on the relevant Garden period. These comparisons reveal that the Botanic Garden has never failed to maintain continuity of work such as expected in a botanic garden. The inal part covers the Botanic Garden in the recent times.

Keywords

botanic garden, colleges, Illyrian Provinces, F. Hladnik, J. Biatzovsky, A. Fleischmann, A. Paulin, J. Lazar, V. Strgar. Running title, University botanic gardens

Abstract

The main goal of the research was to compare the plant response to air pollutants in the rural environment (Zavodnje village) before and after the installation of a desulphurisation device at unit 5 of the Šoštanj Thermal Power Plant (Slovenia). The installation of the cleaning device for SO 2 in the year 2001 caused very signiicant reduction of annual average SO 2 emission

and immission, while concentrations of dust particles, O 3 , NO x , and CO 2 in Zavodnje remained unchanged. On the other hand the average concentrations of ozone during seasonal experimental period increased after 2001, but there were no signiicant differences in AOT40. The impact of O 3 in combination with other air pollutants was studied at Zavodnje in the period 1996–2003 using white clover ( Trifolium repens ‘Regal’) on the basis of visible ozone injuries of leaves, biomass reduction and by analysis of chosen biochemical stress parameters in leaves – the content of plant pigments and antioxidants. The effects of reduction of SO 2 after 2001 were observed in the biochemical responses of white clover plants, which showed better vitality. Despite of that, there

was no signiicant difference in the level of plant injury by ozone between the period 1996–2000 and period 2001–2003. Biomass ratio CN-S/CN-R was also unaffected.

Keywords

air pollution, desulphurization devices, Trifolium repens ‘Regal’; ozone, sulphur dioxide, plant pigments and antioxidants, ozone injuries, biomass

Abstract

Kleptoparasitism is a frequent phenomenon when consumption of prey by predator continues for a relatively long period. This is common when prey is larger or of a similar size as the predator. We built a simple model to study the potential effects of the kleptoparasitism by the brown bears ( Ursus arctos ) on the predation rate of the Eurasian lynx ( Lynx lynx ) in the northern Dinaric Mountains, where the two species coexist. When using data from literature and preliminary studies in the study area, the model suggests substantial increase in the predation rate of the lynx due to the scavenging activity of bears. However, additional data from the ield on the frequency, time course and seasonal variation of the bear’s visits to carcasses are needed, as well as an evaluation of the lynx’ possibilities to increase the predation rate. We suggest that the effects of kleptoparasitism should be considered when evaluating the impact of predation on populations of wild game and during conservation efforts for conservation of endangered carnivore species.

Keywords

Eurasian lynx, Lynx lynx , brown bear, Ursus arctos , kleptoparasitism, interspeciic competition, predation, kill rate, Dinaric Mountains

Abstract

i

Keywords

trace elements, sediment, Velenjsko jezero, Myriophyllum , Najas , Potamogeton , Nuphar

Abstract

Microbial contamination was observed on several subcultures of Pyrethrum ( Tanacetum cinerariifolium ) (Trevir.) Schultz-Bip. callus lines. The presence of microorganisms was detected by isolation of contaminants in pure culture from 7 out of 34 callus lines and direct ampliication of eubacterial 16S rDNA in the pyrethrum callus and plants and isolated bacteria. Altogether 16 contaminants were further analyzed, observing their morphology on several media and restriction of ampliied 16S rDNA. Analysis revealed presence and persistence of morphologically and genetically diverse bacteria in pyrethrum tissue culture. Due to cross reactivity of 16S rDNA primers with DNA of plant origin, no conclusions could be drawn on the origin of contaminants.

Keywords

tissue culture / pyrethrum / Tanacetum cinerariifolium / callus culture / microbial contamination / PCR

Abstract

During starvation on carbon and energy Escherichia coli K-12 cells, modiied to possess EbgA51 as the only 2-galactosidase enzyme, experience adaptive mutations in the ebgR repressor gene. In this way, cells acquire the capacity to utilize the lactulose as the only source of carbon and energy and begin to grow. Adaptive mutations at ebgR are mediated largely by insertion sequences, 40% of adaptive mutants contain IS30 insertions. Also, besides sensing extracellular Mg 2+ , a PhoP-PhoQ system decreases the adaptive mutation rate to ebgR in a to-date unknown way. By performing luctuation tests and genetic analyses, we tested the hypothesis that Mg 2+ plays an important role in the adaptive mutation at ebgR . Results gathered with phoP and phoQ mutant strains demonstrated that the adaptive, but not the growth-dependent, mutation rate is increased by a high extracellular Mg 2+ concentration. In an Mg 2+ -rich environment, the phoQ cells experience a nearly identical adaptive mutation rate as the wild-type strain. Results with the wild-type strain show that the relation between the levels of PhoP-PhoQ expression and the adaptive mutation rate is not as straightforward as expected and that different Mg 2+ concentrations do not affect IS30 transposition. We discuss the possible role of magnesium in the adaptive mutation process.

Keywords

Adaptive mutation, magnesium, Escherichia coli , PhoP-PhoQ, ebg operon, IS30, gene regulatory network