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  • Author or Editor: T. Vida x
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As bas-reliefs of a similar standard are not known in the early Bizantine world, the styles of the figures and the ornamental elements of the jug are compared to the relief works of other fields of art (silver toreutics, ebony carvings, plastic relief, mosaics), since they met the same ideological and aesthetic demands, which necessarily led to the same stylistic solutions (figure-carpets-style) . The scenes are characteristically divided into isolated zones without the existence of a narrative contact. The isolated scenes represent combats between people and animals (venation) in their pure dramatic appearances. This suspense is eased by the agility that can be read from the posture of the hunters. Yet they are hunting scenes and as antithetic combats they bear isolated effects on the spectators. The representation of the people and the animal is true to nature, they do not cover each other and thus they have strong contours and a more emphatic plasticity. Contrary to the individual scenes, the composition of the friezes on the Budakalász jug does not give a dynamic impression since the scale relations are diverse in the individual scenes. A definite aspiration to a formal abstraction can be felt in the composition of the friezes and the order of the scenes. The message is cyclically repeated in the cyclical iteration of the endless series of pictures. The hunter is not an everyday person: he is a hero (heros) who triumphs (virtus) over the difficulties of life.

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Large numbers of wheat genotypes were grown under field conditions and screened for biotic stress tolerance and certain protective compounds. It was found that both the salicylic acid and polyamine contents of the investigated genotypes varied over a wide range, while the antioxidant enzyme activities showed a similar pattern in the different genotypes. In order to investigate stress-induced changes in salicylic acid and polyamine contents, samples were collected from plants artificially inoculated with leaf rust (Puccinia triticina), on which natural powdery mildew [Blumeria graminis (DC.) Speer f. sp. tritici Em. Marchal] infection also appeared. Biotic stress mostly resulted in elevated levels of total salicylic acid and polyamines in all the genotypes. The activities of various antioxidant enzymes showed similar changes after infection regardless of the genotype. The investigation was aimed at detecting a relationship between the level of stress tolerance and the contents of protective compounds, in particular salicylic acid and polyamines.

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We studied the early vegetation dynamics in former croplands (sunflower and cereal fields) sown with a low-diversity seed mixture (composed of 2 native grass species) in Egyek-Pusztakócs, Hortobágy National Park, East-Hungary. The percentage cover of vascular plants was recorded in 4 permanent plots per field on 7 restored fields between 2006 and 2009. Ten aboveground biomass samples per field were also collected in June in each year. We addressed two questions: (i) How do seed sowing and annual mowing affect the species richness, biomass and cover of weeds? (ii) How fast does the cover of sown grasses develop after seed sowing? Weedy species were characteristic in the first year after sowing. In the second and third year their cover and species richness decreased. From the second year onwards the cover of perennial grasses increased. Spontaneously immigrating species characteristic to the reference grasslands were also detected with low cover scores. Short-lived weeds were suppressed as their cover and biomass significantly decreased during the study. The amount of litter and sown grass biomass increased progressively. However, perennial weed cover, especially the cover of Cirsium arvense increased substantially. Our results suggest that grassland vegetation can be recovered by sowing low diversity mixtures followed up by yearly mowing. Suppression of perennial weed cover needs more frequent mowing (multiple times a year) or grazing.

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Treatment with various concentrations (0, 5, 15 and 20%) of PEG was used to simulate water stress, followed by inoculation with Drechslera tritici-repentis (DTR) at two different points of time (6 and 72 h after the PEG treatment) in two DTR resistant (M-3 and Mv Magvas) and two sensitive (Bezostaya 1 and Glenlea) wheat varieties. The reduction in biomass production due to the PEG treatments was more pronounced in the shoots than in the roots. While in the case of Bezostaya 1 5% PEG reduced the level of infection, 20% PEG treatment lowered the tolerance level of M-3. DTR infection may be more efficient in inducing antioxidative defence systems than water stress. However, there was no direct correlation between the activity of the individual antioxidant enzymes and the drought or DTR tolerance of wheat plants.

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Acta Agronomica Hungarica
Authors: G. Vida, M. Cséplő, G. Gulyás, I. Karsai, T. Kiss, J. Komáromi, E. László, K. Puskás, Z. Wang, C. Pace, Z. Bedő, L. Láng and O. Veisz

Among the factors which determine yield reliability an important role is played by disease resistance. One of the breeding aims in the Martonvásár institute is to develop wheat varieties with resistance to major diseases. The winter wheat varieties bred in Martonvásár are examined in artificially inoculated nurseries and greenhouses for resistance to economically important pathogens. The effectiveness of designated genes for resistance to powdery mildew and leaf rust has been monitored over a period of several decades. None of the designated major resistance genes examined in greenhouse tests is able to provide complete resistance to powdery mildew; however, a number of leaf rust resistance genes provide full protection against pathogen attack (Lr9, Lr19, Lr24, Lr25, Lr28 and Lr35). In the course of marker-assisted selection, efficient resistance genes (Lr9, Lr24, Lr25 and Lr29) have been incorporated into Martonvásár wheat varieties. The presence of Lr1, Lr10, Lr26, Lr34 and Lr37 in the Martonvásár gene pool was identified using molecular markers. New sources carrying alien genetic material have been tested for powdery mildew and leaf rust resistance. Valuable Fusarium head blight resistance sources have been identified in populations of old Hungarian wheat varieties. Species causing leaf spots (Pyrenophora tritici-repentis, Septoria tritici and Stagonospora nodorum) have gradually become more frequent over the last two decades. Tests on the resistance of the host plant were begun in Martonvásár four years ago and regular greenhouse tests on seedlings have also been initiated.

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