Lemna minor is a species easy to collect and culture in laboratory, and can give rapid test results. However, in order to standardise toxicity tests using Lemna minor as test organism, it is important to find out what natural variability different populations might have. Five Lemna populations were used for comparison. It contained two standard cultures and three populations collected in natural habitats. Potassium dichromate was applied as test material. Lemna populations cultured under the same condi- tions showed different TD and LC50 values. There is an inverse relation between the sensitivity and TD of the strains. It is supposed that growth rate and sensitivity of Lemna populations depend on environmen- tal factors characterising the habitat in which the given popluation originally lives.
Two wheat-infecting isolates of WDV-WDV-B and WDV-F-
were collected in the field of Martonvásár and Nagykovácsi.
The complete genomes were amplified by PCR, cloned into pBKS+ plasmid and
sequenced. The nucleotide divergence in the total genome of the five isolates-WDV- Fra, WDV-Cz, WDV-Swe, WDV-B and WDV-F-originating from different part of Europe were found to be
0.44-1.69%. The four genes-
MP, CP, RepA and Rep-and two non-coding region-LIR and SIR-
were compared and a phylogenetic tree was constructed.
In order to investigate whether some corn
hybrids of various seasonal growing rates (FAO numbers) are damaged by larvae of cotton bollworm,
(Lepidoptera, Noctuidae) in different levels, a set of field experiments was conducted at Mezőhegyes, Southeast Hungary, in course of 2003–2004. Phenological stages of corn hybrids and pattern of captures of
moths in pheromone traps were monitored in course of the season. Abundances of larvae of the next generation on developing cobs were also recorded. At harvest, the weight of grains damaged by
larvae, as well as the total weight of grains taken off from cobs were measured for each corn hybrids.At the time of peak flight in 2003, freshly hatched larvae appeared in the cobs of those hybrids which were already flowering (female flower), i.e. reached the silking stage, as in case of DK 391, DK 443 and Maraton (FAO numbers: 300, 380 and 450, respectively), while L
larvae were found in the cobs of Maxima (FAO number: 580), only considerably later, when it reached silking stage. In 2004, however, all hybrids, including Maxima, flowered by the time of peak flight, and L
larvae appeared on cobs of each hybrids without delay.The mean number of larvae was the highest in 2003 in DK 391 (141.5±4.5 larvae / 50 cobs), while DK 443, Maraton and Vilma did not differ significantly from each other (92.0±10.0, 88.5±3.0 and 78.8±3.4 larvae / 50 cobs, respectively). The lowest number of larvae was found in Maxima (34.0±3.0 larvae / 50 cobs). In contrast to this, the highest number of larvae were found on Maxima in 2004, differring significantly from that of DK 391, DK 391 and Maraton, these latter three hybrids housing only negligible low numbers of larvae.The mean weight of damaged grains per cob was the highest in DK 391 (3.5±0.6 gram) and lowest in Maxima (1.1±0.2 gram), differring from each other significantly, in 2003. A reverse result was obtained in 2004, when far the highest weight of damaged grains per cob was found in Maxima (112.2±0.7 gram), while pratically no damage occurred at DK 331, DK 443 and Maraton.The mean weight of all grains per cob was the highest in 2003 in Maraton (111.5±5.3 gram) and the lowest for DK 391 (79.2±4.3 gram), the difference being statistically significant. In 2004, however, no significant differences were found in this respect (values ranged from 162.9±2.8 gram to 192.4±21.0 gram).These results indicate that the abundace of
larvae on cobs and subsequent damage depends on the coincidence of silking of corn and peak capture of moths in pheromone traps, and not on features of the corn hybrid. Differences found in this study among hybrids barely reflect to the above-mentioned coincidence, therefore the level of infestation of the studied hybrids may vary by years and localities, and does not imply an inherent tolerant feature of the hybrids concerned. It is discussed that control measures should be considered to perform without delay in cases whenever such a coincidence is observed.
In Hungary rice (
L.) is cultivated under flooded conditions. Direct seeding into the soil is applied usually. The optimal sowing date is a key factor necessary to the success of this annual crop because of the relatively short growing season. The main objective of this research was to: (1) analyse duration of period from sowing to emergence at different temperature values, (2) determine base temperature of this phenophase and (3) establish a thermal time model for rice emergence. To do this, growth chamber experiments with 5 Hungarian cultivars were conducted to determine the time to median emergence (E
) at constant temperature of 14 to 34 °C in 2 °C steps. The sowing depth was 2 cm, and moisture was not a limiting factor. It was found that the critical thermal zone, which is of highest practical importance, is between 14 and 16 °C. At these values the E
is 23.9 and 13.4 days, respectively, showing a border between unfavourable and acceptable conditions. In the temperature interval between 26 and 34 °C the time needed for emergence was only 3.3 to 4.4 days. Variety differences were also detected. Base temperature was found between 9.8 and 10.9 °C. The thermal time requirements of 4 cultivars varied between 69 and 73 °C day. Data of field experiment with 9 sowing dates and a pot experiment with 3 sowings confirmed that our thermal time model can successfully simulate the emergence of rice.
Investigations of the possible use of Mössbauer measurements for the analysis of the corrosion products of iron are reported.
The Mössbauer spectrum was measured at room and liquid nitrogen temperatures on two samples produced by different corrosion
procedures. The isomeric shift, quadrupole splitting and magnetic splitting observed in the spectra yield information on the
chemical composition. In this way, the chemical forms of the compounds in the samples could be established. The magnetic properties,
revealed by the spectra taken at different temperatures, permitted the identification of the polymorphous modifications. The
rust produced in air saturated with water vapour was found to consist of 50% (w/w) Fe2O3,∼40% γ-FeOOH, and ∼10% β-FeOOH, while the rust produced by periodical immersion in saturated calcium chloride solution is
composed of about equal amounts of β-FeOOH and γ-FeOOH. These findings have been confirmed by the thermoanalytical curves
of the samples. The Mössbauer effect presents a convenient method for the investigation of the corrosion products of iron.
Energy efficiency measures and the enhancement of investments in renewable energy play important role in sustainable development and lead to advancement of competitiveness of national economies. The increase of renewable energy consumption and the reduction of greenhouse gas emissions are significant stages of the process to achieve the main purposes of sustainable development at global and national levels.
In this paper the change in the share of renewable energy in gross final energy consumption and in the greenhouse gas emissions intensity in Hungary between 2004 and 2011 is investigated.
It is demonstrated that the share of the renewable energy in gross inland energy consumption increased during the examined period. The measure and the tendency of the change in Hungary show similarity to the EU 27 average.
The greenhouse gas emissions intensity of energy consumption decreased in Hungary between 2004 and 2011. According to the data, the decrease is the second largest among the European Member States.
In this paper we analyse the trends and developments of energy imports as a percentage of gross inland energy consumption including bunkers in Hungary and the European Union countries between 2000 and 2011. Data show that the average of the energy dependence increased in the EU27 Member States (7.1 percentage points) and in Hungary, too (3.4 percentage points). The energy intensity in Member States is examined as well. According to the data the energy intensity decreased in the majority of the Member States, the average decreased by 16 percent.
During the analysis of environmental risk posed by hazardous waste disposal sites, ecological impact on whole ecosystems should be assessed. It requires a complex testing scheme where surrogate species represent key elements of the ecosystem. However, different organisms are exposed to a differing degree, also, their sensitivity to the same contaminant may vary. A possible way to determine which test reflects most the actual toxic conditions, correlation can be calculated between the measured ecological parameter (such as growth inhibition, mortality, etc.) and a contaminant gradient. The basic aim of this study was to determine which ecotoxicological test shows the best correlation with the measured analytical parameters. The selected tests were Lemna minor (representing primary producers), Thamnocephalusplatyurus (a primary consumer organism) and Vibrio fischeri (decomposer). When testing soil samples, the Thamnocephalus test showed excellent consistency with most contaminants but was oversensitive in the case of groundwater samples. The Vibriofischeri bioluminescence inhibition test (ToxAlert) behaved in a different way, reflecting well the distribution of most contaminants in groundwater samples. Finally, Lemna test proved to be completely inadequate.
The transitions between various developmental phases are critical in determining the ecological adaptation and yield of cereals. In order to elaborate a methodology for establishing the timing of the consecutive plant developmental phases from germination to the fully developed plant, regular measurements of changes in developmental components were carried out on one winter (Kompolti Korai) and one spring (Morex) barley cultivar in a model experiment. Under the controlled environmental conditions linear regression was characteristic of the associations between the chronological time and all or most of the time course data of plant height, tiller and leaf numbers. The initial growth of the spring barley was twice as intensive as that of the winter barley. The length of the stem elongation phases was similar for the two varieties, but the winter barley cultivar showed significantly more intensive stem growth compared to the spring barley. The spring barley reached all the plant developmental phases significantly earlier than the winter barley. For both cultivars, tillering continued till after first node appearance and there was a definite delay between first node appearance and the beginning of the stem elongation phase. The determination of the full series of phenophases, together with the evaluation of various yield components on the same plant, provide an excellent way of establishing plant developmental patterns and may make a significant contribution to achieving a better understanding of the associations between plant developmental patterns and the adaptation and yielding ability of cereals.