DRUŠTVO BIOLOGOV SLOVENIJE
Biological Society of Slovenia

 

 

Contents (Abstracts)

Volumes

11: 1 (1963)    40: 3-4 (1995)    42: 2 (1999)    43: 3 (2000)    44: 1-2 (2001)    45: 2 (2002)    46: 1 (2003)    47: 1 (2004)    47: 2 (2004)    48: 1 (2005)    48: 2 (2005)    49: 1 (2006)    49: 2 (2006)    50: 1 (2007)    50: 2 (2007)    51: 1 (2008)    51: 2 (2008)    52: 1 (2009)    52: 2 (2009)    53: 1 (2010)    53: 2 (2010)    54: 1 (2011)    54: 2 (2011)    55: 1 (2012)    55: 2 (2012)    56: 1 (2013)    56: 2 (2013)    57: 1 (2014)    57: 2 (2014)    58: 1 (2015)    58: 2 (2015)    59: 1 (2016)    59: 2 (2016)    60: 1 (2017)    60: 2 (2017)   

Contents: Volume 60, Nr. 2 (2017)


Essential oils with the potential for varroa mite control ( Varroa destructor): mechanisms of toxicity and negative impact on honey bee ( Apis mellifera)


Anita Jemec Kokalj, Gordana Glavan

Abstract

The parasitic bee mite varroa ( Varroa destructor ) is among the most

serious honey bee pests. Beekeepers utilize a wide range of different synthetic acaricides

to keep mite populations under control. However, due to documented adverse

impact of synthetic substances, the use of naturally derived acaricides, among these

essential oils, is greatly being promoted. Thymol is already used in beekeeping. We

present a review of the existing knowledge regarding the effects of essential oils on

honey bees Apis mellifera . We focus only on those that have potential acaricide action.

We discuss their mechanisms of toxic action on the immune and nervous systems. We

conclude that due to their mechanisms of toxicity several essential oils could be used

for varroa mite control, still very little data regarding the negative effects of essential

oils on honey bees are known. In particular, knowing their interferences with the

immune response is important to be able to predict the potential effect on the colony

health. The majority of toxicity data currently exist for thymol and its commercial

preparations under acute exposure (Apiguard ® , Api Life VAR ® ), but the data for a

number of other potential acaricide-related essential oils are missing. We recognize

the need for systematic screening of potential toxicity and sublethal effects of essential

oils with acaricide action on honey bees. Standardised application of essential oils in

honey bee keeping remains a challenging task for the future.

Keywords

acaricides, essential oils, Apis mellifera , nervous system, immune system, varroa mite


Evaluation of cyanobacteria biomass derived from upgrade of phycocyanin fluorescence estimation


Tinkara Rozina, Bojan Sedmak, Maja Zupančič Justin, Andrej Meglič

Abstract

The number of harmful cyanobacterial blooms has increased significantly

at the global level in recent years. One of the characteristics of cyanobacteria that

gives them advantage over other phytoplankton organisms are auxiliary photosynthetic

pigments, such as phycocyanin. This fluorescent pigment emits light at a different

wavelength as chlorophyll and can therefore be used for detection of cyanobacteria

in situ . In this study we used submersible phycocyanin fluorescence sensors and

compare their voltage output to concentration of extracted phycocyanin, cell counts

and biovolume. The relation was linear in all three cases; however, the variability of

regression line slopes between different cyanobacteria strains was high in the case of

PC extract concentration and cell count. The highest uniformity in the linear fits was

between fluorescence signal and biovolume therefore making it the best candidate for

fluorescence sensor voltage output conversion. In the context of this work we also

compared different methods for PC extraction. Modifying the equations by subtracting

the absorption at 750 nm almost entirely reduces the false PC concentration estimation

due to sample turbidity.

Keywords

fluorescence measurements, phycocyanin, cyanobacteria


Impact of UV radiation and selenium on two buckwheat species


Aleksandra Golob, Vekoslava Stibilj, Judita Turk, Ivan Kreft, Mateja Germ

Abstract

The impact of selenium (Se) addition and UV radiation on Tartary

buckwheat and hybrid buckwheat were studied. Both buckwheat species grew outdoors

at the experimental field of the Biotechnical Faculty in Ljubljana. They were exposed

to four different treatments regarding the UV radiation (ambient or reduced) and added

Se (naturally accessible or foliary treated with Na selenate in concentration 10 mg Se

L -1 ). The content of pigments (chlorophyll a and b , carotenoids, anthocyanins) and

UV absorbing compounds, transpiration rate, photochemical efficiency of photosystem

II (PS) II and respiratory potential were measured. At the end of experiment we

determined the biomass of different plant parts. The results showed that irrespective

of the buckwheat species the added Se lowered the content of chlorophyll a and

carotenoids, while it increased the effective quantum yield of PS II and transpiration

rate. UV radiation reduced the content of anthocyanins only. Se and UV-B radiation

as independent factors exerted no impact on buckwheat yield. Hybrid buckwheat had

a higher physiological activity than the Tartary buckwheat yet a smaller biomass of

plant parts, including reduced yield. Ambient UV radiation had a slightly negative

impact on hybrid buckwheat while it had no noticeable negative impact on Tartary

buckwheat. The Se treated Tartary and hybrid buckwheat were suitable for human and

animal diet regarding to Se concentrations in leaves and grains.

Keywords

Tartary buckwheat, hybrid buckwheat, selenium, selenate, UV ra diation


Response of macrophyte Berula erecta to low concentrations of NaCl in vitro


Špela Mechora, Jana Ambrožič Dolinšek

Abstract

Macrophyte Berula erecta, grown in tissue culture, was exposed to

various low concentrations of NaCl in the water (1–100 mg L -1 ). Added NaCl had a

positive effect on plant’s growth and development. The number of shoots increased,

as well as the length of the roots. The lowest concentration (1 mg L -1 ) increased

photochemical efficiency of photosystem II (Fv/Fm) while the highest (100 mg L -1 )

slightly decreased it. Chlorophyll content was negatively affected by NaCl addition

after 3 weeks. Carotenoid and anthocyanin levels were firstly raised and later lowered

in NaCl treatment comparing to control. Overall, added NaCl had no negative effect

on plants morphology, while decreased amount of pigments was observed.

Keywords

NaCl, Berula erecta , photochemical efficiency, growth parameters, pigments


Identification of alien Fallopia taxa using molecular methods


Simona Strgulc Krajšek, Mersiha Bjelić, Sabina Anžlovar

Abstract

The non-native species of knotweeds ( Fallopia sect. Reynoutria ) are

morphologically very similar and it is often difficult to distinguish between the hybrid

F. ×bohemica and parental taxa, F. japonica and F. sachalinensis . To distinguish 30

samples of knotweeds, collected in Slovenia, we used PCR RFLP analysis of the

trn K intron of plastid DNA in combination with the amplification of microsatellite

nuclear locus KW6, which is a specific diagnostic marker for F. sachalinensis . We

established that the combination of both markers unambiguously identifies the following

samples: F. japonica (var. japonica ), F. sachalinensis and F. × bohemica. Based

on described molecular markers we confirmed that the maternal parent of the taxon

F. × bohemica was F. japonica for all analysed hybrids. In addition, two species from

Fallopia sect. Sarmentosae ( F. baldschuanica and F. multiflora ) were also analysed.

Both could be distinguished from species of Fallopia sect. Reynoutria, but for the

discrimination between them, some other markers should be used.

Keywords

Fallopia , invasive species, Slovenia, hybridization, plastid DNA, trn K, microsatellite locus, KW6, RFLP


Herbarium in primary teacher education


Gregor Torkar, Irma Mavrić

Abstract

In this article, we define the importance of herbarium in primary teacher

education to enhance primary school student’s interest in, and knowledge of plants.

Slovene pre-service primary school teachers were trained to make their own herbarium.

The study involved 86 undergraduate students. After making their own herbarium

they completed a written questionnaire about gained knowledge and experiences. The

results show that students, while making herbarium, learned on average three new

plant species. 74 % of students reported having some difficulties in determination

of plant species and the herbarization procedures. More than two thirds of students

reported that they experienced making herbarium in primary or secondary school.

Most of them in science and biology classes in primary school. All, except one, plan

to use herbarium in their teaching practice. They see the potential of the activity in

teaching primary school students about plant anatomy and species diversity, science

skills, work attitudes and attitudes towards biology. To conclude, participating students

demonstrated desired level of content knowledge and pedagogical content knowledge

to successfully implement the herbarium into primary education, which could be

beneficial in enhancing primary school student’s interest in, and knowledge of plants.

Keywords

herbarium, student, competences, botany, school


Connected with plants for last 35 years


Marina Dermastia

Abstract

In 2017 we, the members of the Slovenian Society of Plant Biology,

celebrate 35 years of continuous action although not under the same name and not

with the same members. Many things have changed during those years, but our true

passion to uncover the secret life of plants has remained the same.

Keywords

plant biology, plant physiology, society

 

© 2003, Društvo biologov Slovenije –
Journal of Biological Society of Slovenia

Zadnja sprememba:
15.3.2010