8 results on '"Pálfi X"'
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2. Texture properties and phenol extractability indices of the grape berry under pre- and post-veraison water deficit (Vitis vinifera L. 'Kékfrankos')
- Author
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Zsófi, Z., Pálfi, X., and Villangó, S.
- Abstract
Optimal water supply is one of the most important factors in quality wine making. However, water availability is limited in several wine regions and water shortage is getting even worse due to climate change, especially under arid climate conditions. Therefore, proper water management of the vineyards, the amount and the timing of irrigation will play a crucial role in sustainable viticulture in the near future. In this study, the effect of timing of moderate water deficit on berry texture characteristics and phenolic maturity were investigated. 'Kékfrankos' grapevines were submitted to different water regimes: moderate water deficit from berry set until veraison (WD1), moderate water deficit from veraison until harvest (WD2), no water deficit (C). Concentration of the phenolic components of the grape berry skins and berry mixture for the Glories indices were measured by spectrophotometer (UVmini-1240 CE UV-VIS, Shimadzu, Japan). Cell and seed maturity indices (CMI%, SMI%) were also calculated. Berry texture characteristics were monitored by a TA.XT Plus Texture Analyser (Stable Micro System, UK). Berry skin and seed texture properties were affected by water regimes. Skin and seed hardness of WD1 were significantly lower than those of WD2. Significant differences were found in berry hardness between the treatments (C>WD1>WD2). Berry gumminess, resilience and chewiness of WD2 were lower compared to C and WD1. Anthocyanin extractability was higher when plants were not subjected to post-veraison water limitations (WD1). Furthermore, the seed maturity index was lower when water deficit occurred between berry set and veraison. Pre-veraison water deficit resulted in delayed ripening, softer seeds and thus higher phenol extractability compared to WD2 and C. Late seasonal water deficit resulted in thicker skins, which was accompanied by lower anthocyanin extractability than in WD1 and C. It seems that anthocyanin extractability is influenced by the actual water status of the grapevine rather than skin textural properties. However, there are some connections between skin texture parameters and maturity indices., VITIS - Journal of Grapevine Research, Vol. 60 No. 3 (2021): Vitis
- Published
- 2021
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3. Combined effect of berry size and postveraison water deficit on grape phenolic maturity and berry texture characteristics (Vitis vinifera L. 'Portugieser')
- Author
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Zsófi, Z., Villangó, S., Pálfi, Z., and Pálfi, X.
- Subjects
integumentary system ,food and beverages - Abstract
The effect of berry size and moderate water deficit on skin phenolic maturity and berry texture behaviour was studied on 'Portugieser' (Vitis vinifera L.) under green house conditions. In all berry weight categories (I: < 1.1 g; II: 1.11-1.4 g; III: 1.41-1.7 g; IV: 1.71-2 g; V: > 2,01 g) water deficit resulted in reduced sugar concentration due to decreased photosynthetic activity. Interestingly, lower phenolic concentration for unit skin mass was measured in the drought stressed treatment compared to the control, irrespective of berry size. However, the concentration of the phenolic components for one berry was lower in the well watered treatment. This phenomenon was due to the increased skin/flesh ratio of the water stressed vines. Berry skin hardness was probably in connection with its phenolic concentration for unit skin weight. Changes in several berry texture parameters were accompanied by changes in berry size. Berry hardness and skin elasticity increased with berry size in both treatments. On the other hand, skin break force, skin break energy, skin thickness showed increase/decrease only in the case of the stressed vines. This result suggests that texture properties of the water-stressed berries depend on berry size to a greater extent compared to the berries of the non-stressed vines. This phenomenon may be explained by the faster ripening of the smaller and of the water stressed berries., VITIS - Journal of Grapevine Research, Vol. 54 No. 4 (2015): Vitis
- Published
- 2015
- Full Text
- View/download PDF
4. Role of Aspergilli and Penicillia in mycotoxin contamination of maize in Hungary
- Author
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Tóth, B., primary, Török, O., additional, Kótai, É., additional, Varga, M., additional, Toldiné Tóth, É., additional, Pálfi, X., additional, Háfra, E., additional, Varga, J., additional, Téren, J., additional, and Mesterházy, Á., additional
- Published
- 2012
- Full Text
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5. Role of Aspergilliand Penicilliain mycotoxin contamination of maize in Hungary
- Author
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Tóth, B., Török, O., Kótai, É., Varga, M., Toldiné Tóth, É., Pálfi, X., Háfra, E., Varga, J., Téren, J., and Mesterházy, Á.
- Abstract
Aspergillusand Penicilliumspecies and their mycotoxins, including aflatoxins, ochratoxins, fumonisins and patulin, are frequently encountered on cereal products. The occurrence of these species and their mycotoxins on maize was investigated in Hungary after harvest in two consecutive years. Surface-sterilized cereal seeds were placed on selective media, and the isolated fungal strains were identified using morphological methods. In 2010 and 2011, 81.94% and 14.33%, respectively, of the samples were found to be contaminated with potentially toxigenic isolates. The species identification of selected isolates was carried out using sequence-based methods. Several Aspergillus flavusisolates were identified, which are potential aflatoxin producers. Other mycotoxinproducing species were also isolated, including black Aspergilli, which potentially produce ochratoxins and fumonisins, and A. clavatus, which produces patulin. In 2010 a large number of Penicilliumspecies occurred in the samples, producing a wide range of mycotoxins. The mycotoxin content of the samples was analysed using the ELISA and HPLC techniques. Aflatoxins were not detected in any of the samples, while ochratoxins and fumonisins were successfully identified in some of the maize seeds.
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- 2012
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6. Comprehensive analyses of the occurrence of a fungicide resistance marker and the genetic structure in Erysiphe necator populations.
- Author
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Pintye A, Németh MZ, Molnár O, Horváth ÁN, Matolcsi F, Bókony V, Spitzmüller Z, Pálfi X, Váczy KZ, and Kovács GM
- Subjects
- Erysiphe, Europe, Genotype, Fungicides, Industrial pharmacology
- Abstract
Genetically distinct groups of Erysiphe necator, the fungus causing grapevine powdery mildew infect grapevine in Europe, yet the processes sustaining stable genetic differences between those groups are less understood. Genotyping of over 2000 field samples from six wine regions in Hungary collected between 2017 and 2019 was conducted to reveal E. necator genotypes and their possible differentiation. The demethylase inhibitor (DMI) fungicide resistance marker A495T was detected in all wine regions, in 16% of the samples. Its occurrence differed significantly among wine regions and grape cultivars, and sampling years, but it did not differ between DMI-treated and untreated fields. Multilocus sequence analyses of field samples and 59 in vitro maintained isolates revealed significant genetic differences among populations from distinct wine regions. We identified 14 E. necator genotypes, of which eight were previously unknown. In contrast to the previous concept of A and B groups, European E. necator populations should be considered genetically more complex. Isolation by geographic distance, growing season, and host variety influence the genetic structuring of E. necator, which should be considered both during diagnoses and when effective treatments are planned., (© 2023. Springer Nature Limited.)
- Published
- 2023
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7. Paraffin oil induces resistance against powdery mildew in grapevine through salicylic acid signaling.
- Author
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Pálfi X, Lovas M, Zsófi Z, Kátai J, Karácsony Z, and Váczy KZ
- Subjects
- Humans, Oils, Paraffin, Plant Diseases, Salicylic Acid pharmacology, Ascomycota, Disease Resistance
- Abstract
Background: Mineral oils have been widely used in the pest control of several crops. However, their mode of action is poorly understood, especially in the case of their antifungal properties. The possible direct fungicidal activity and the stress-inducing capability of paraffin oil on grapevine were examined using Vitis vinifera L. cv 'Kékfrankos' cuttings and the fungus Erysiphe necator, the causal agent of powdery mildew., Results: Our experiments demonstrated that paraffin oil does not have fungicide activity on E. necator, but induces significant stress-related changes in grapevine physiology. Elevated H
2 O2 production and the accumulation of the phytohormone salicylic acid were measured. Secondary thickening of the cell wall by lignin deposition and the accumulation of phenolic compounds were also observed. Some enzyme activities related to the detoxification of reactive oxygen species, disease response, and the synthesis of lignin were changed in accordance with the determined changes in cell wall composition and H2 O2 levels., Conclusion: The results suggest that paraffin oil induces stress responses on grapevine leaves through oxidative burst, and this response is systemized by salicylic acid. The accumulation of lignin and water-soluble phenolics may be directly responsible for the paraffin oil-induced resistance of grapevine against powdery mildew. © 2021 Society of Chemical Industry., (© 2021 Society of Chemical Industry.)- Published
- 2021
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8. Physico-Chemical Characteristics and Culturable Microbial Communities of Grape Berries Change Strongly during Noble Rot Development.
- Author
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Hegyi-Kaló J, Hegyi ÁI, Geml J, Zsófi Z, Pálfi X, and Váczy KZ
- Abstract
Botrytis cinerea is a well-known pathogen of grapevine. However, under certain microclimatic conditions, Botrytis infection results in noble rot, an essential process in the production of the world-known Tokaji aszú wines in Hungary. We investigated the physico-chemical characteristics and culturable microorganisms associated with grape berries through several noble rot phases in the two main cultivars grown in Tokaj: Vitis vinifera cv. " Furmint " and " Hárslevelű ". We measured physical and analytical parameters routinely tested in viticulture and analyzed the ITS rDNA sequence data of fungi isolated from the sampled berries. We observed significant differences in the physico-chemical parameters among the noble rot phases as well as sampling dates. The greatest variation in berry texture and microbial structure was observed in the initial phases, with variables converging as the noble rot progressed. By finding a bijection between the examined chemical properties and the factorial parameters (e.g., noble rot phase, collection time, cultivar), an appropriate sweet winemaking material can be designed. Fungal community differed significantly among cultivars, with higher number of species observed in Hárslevelű . Our results reveal that there is more to noble rot than only Botrytis cinerea and other microorganisms may play important roles in the aszú process.
- Published
- 2020
- Full Text
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