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The drought stress tolerance of three accessions of Aegilops biuncialis Vis. (Ae225, Ae550 and Ae1050) and two varieties of Triticum aestivum L. (Sakha and Cappelle Desprez) was compared. The activity of superoxide dismutase (SOD) isoenzymes, which reflects the intensity of oxidative stress, changes in the malonic dialdehyde (MDA) content, formed during the lipid peroxidation induced by stress situations, and the inducibility of electron removal systems appearing as an alternative to CO 2 fixation were chosen for the present investigations. Drought stress was simulated using polyethylene glycol (PEG). The order of drought stress tolerance obtained correlated well with the original habitats ofthe varieties. The present results provide a clear illustration of the fact that tolerant varieties respond differently for the parameters tested, suggesting that their resistance can be attributed to different mechanisms. Abbreviations:CuZnSOD=superoxide dismutase isoform with Cu and Zn cofactor metals, MnSOD and FeSOD=superoxide dismutase isoform with Mn and Fe cofactor metals, PVP25= polyvinyl pyrrolidone 25, MDA=malonic dialdehyde, PEG=polyethylene glycol, TCA=trichloro acetic acid, TBA=thiobarbituric acid, ΔF=F m -F s , F m =maximal fluorescence yield, F s =fluorescence yield in steady state

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Fatty acid hydroperoxide-producing lipoxygenase (LOX) and hydroperoxide-degrading glutathione peroxidase (GPOX) enzyme activities were studied in leaves of virus resistant Xanthi-nc and susceptible Samsun-nn tobacco cultivars after inoculation with Tobacco mosaic virus (TMV). Total LOX activity showed a maximum at pH 5.5 in cell-free extracts of uninfected leaves. LOX activity markedly increased at this pH after TMV inoculation, but a substantial induction was detected also in the basic pH range with an emerging peak around pH = 8.5. TMV-elicited LOX induction was weaker and appeared later in Samsun-nn than in Xanthi-nc leaves. GPOX activity was also substantially induced by TMV infection. However, this induction appeared only 4 days post-inoculation in resistant Xanthi-nc plants in tissues surrounding the localized necrotic lesions. In contrast, GPOX activity did not change in TMV-inoculated, susceptible Samsun-nn leaves. Several glutathione S-transferase (GST) isoenzymes also display GPOX activity. The expression of a tau class GST gene was markedly induced by TMV inoculation in Xanthi-nc leaves. This tobacco GST gene was partially cloned and sequenced.

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The present study investigated how sighted and blind sensory assessors evaluated the quality of various apple varieties: Regal Prince (Gala Must), Jonagold Schneica (Jonica), Watson Jonathan, Golden Reinders and Generos. A total of 80 sighted and 12 blind people participated in the study, in three groups (sighted people without blindfolds, sighted people with blindfolds, blind people). The preference of sensory attributes (size, shape, colour, texture, taste and odour) was evaluated on a six-category scale. The data were analysed using single-factor (ANOVA, LSD95%, 99%) and multi-factor (Cluster analysis, ANOVA, LSD95%, 99%) evaluation. The results showed that blind and sighted assessors made similar judgements on external attributes perceptible by touch (size, shape), but differed in their evaluation of certain quality factors (flavour, taste), resulting in opponent patterns of preference on some apple varieties (Generos, Jonagold Schneica). A further conclusion of the experiment is that there was less deviation between the judgements of sighted assessors when they saw the apples than when they were blindfolded. The background of this phenomenon might be explained by the uncertainty and disturbed perception, which lead to inconsistent judgements.

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Erwinia amylovora (Burrill, Winslow et al.) is one of the most important pathogens of pear and apple and subject to strict quarantine regulations worldwide. Fire blight disease causes serious damages in pear orchards in Hungary. The aim of our experiment was to test the susceptibility of pear cultivars to Hungarian E. amylovora isolates under laboratory conditions. For inoculation test isolates were chosen from different host plants, areas and years. Seven traditional pear cultivars were chosen for testing. Fruit infection was rated according to the diameter of spots produced by the pathogen around the inoculation puncture. Cultivars and isolates were assigned to five susceptibility groups (symptomless, low susceptibility, moderate susceptibility, susceptible and very susceptible). The Hungarian Erwinia amylovora isolates showed different results. We found different susceptibility of traditional pear cultivars. The cultivars Alexander Lucas and Stössel tábornok represented the less susceptible category. Eldorado, Serres Olivér, Diel vajkörte were moderately susceptible. Thus, the most susceptible cultivars were Téli esperes and Drouard elnök. In conclusion, these results can be used for the classification of Erwinia amylovora isolates and in future breeding programmes for resistance.

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Acta Botanica Hungarica
Authors:
J. Csiky
,
L. Balogh
,
I. Dancza
,
F. Gyulai
,
G. Jakab
,
G. Király
,
É. Lehoczky
,
A. Mesterházy
,
P. Pósa
, and
T. Wirth

As part of the PADAPT project, the authors compiled the invasion biological database of the alien vascular flora of Hungary, which contains the nativeness, residence time, introduc- tion mode and invasion status of 878 alien or cryptogenic taxa. In the absence of adequate evidence, the classification of some species was only possible into uncertain, transitional cat- egories. The definitions of most categories are compatible with several international termi- nologies, but are primarily based on Central European traditions. Of the 560 taxa that have already been naturalised in Hungary, 85 are invasive, and 22 of them are transformer alien vascular plants. Only 5 of these transformers are included in the European list of Invasive Alien Species of Union concern (Ailanthus altissima, Asclepias syriaca, Elodea nuttallii, Heracleum mantegazzianum and H. sosnowskyi), which require uniform preventive interventions and treatments throughout the continent, while the rest of transformers in Hungary (e.g., Robinia pseudoacacia, Fallopia × bohemica and Solidago gigantea) draw attention to the unique, local and/ or regional invasion biological situation of the Pannonian Basin and Central Europe.

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Acta Botanica Hungarica
Authors:
Cs. Molnár
,
Zs. Molnár
,
Z. Barina
,
N. Bauer
,
M. Biró
,
L. Bodonczi
,
A. Csathó
,
J. Csiky
,
J. Deák
,
G. Fekete
,
K. Harmos
,
A. Horváth
,
I. Isépy
,
M. Juhász
,
J. Kállayné Szerényi
,
G. Király
,
G. Magos
,
A. Máté
,
A. Mesterházy
,
A. Molnár
,
J. Nagy
,
M. Óvári
,
D. Purger
,
D. Schmidt
,
G. Sramkó
,
V. Szénási
,
F. Szmorad
,
Gy. Szollát
,
T. Tóth
,
T. Vidra
, and
V. Virók

The first version of the map of the Hungarian vegetation-based landscape regions were prepared at the scale of 1: 200,000 (1 km or higher resolution). The primary goal of the map was to provide an exact background for the presentation and evaluation of the data of the MÉTA database. Secondly, we intended to give an up-to-date and detailed vegetation-based division of Hungary with a comprehensive nomenclature of the regions. Regions were primarily defined on the basis of their present zonal vegetation, or their dominant extrazonal or edaphic vegetation. Where this was not possible, abiotic factors that influence the potential vegetation, the flora were taken into consideration, thus, political and economical factors were ignored. All region borders were defined by local expert botanists, mainly based on their field knowledge. The map differs in many features from the currently used, country-wide, flora-or geography-based divisions in many features. We consider our map to be temporary (i.e. a work map), and we plan to refine and improve it after 5 years of testing.

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