László Palkovics

36117031200

Publications - 18

Identification of a novel pathogen of the glacial relict Drosera rotundifolia and the impact of the fungus on the conservation of the plant and its habitat

László Palkovics Mátyás Szépligeti János Ágoston A. Tóth L. Szendrei

Publication Name: Fungal Biology

Publication Date: 2025-10-01

Volume: 129

Issue: 6

Page Range: Unknown

Description:

Round-leaved sundew (Drosera rotundifolia L.) is a protected glacial relict plant inhabiting Sphagnum bogs, which are endangered habitats in Hungary. In 2020 and 2021 greyish mycelium growth was observed on the hibernacula of D. rotundifolia in Czech Republic, Germany and Hungary. Samples have been collected in possession of the required permits. The fungus was isolated and identified with classical and molecular methods. Koch's postulates were fulfilled. The novel pathogen was identified as the highly polyphagous Botrytis cinerea in each sample. Simultaneously, field assessments of wild Hungarian populations were carried out. Throughout the survey of three different Hungarian collection sites, altogether 207 hibernacula were carefully examined for gray mold symptoms. Interestingly, only plants grown on milled peat substrate were affected by the pathogen. The antifungal and antimicrobial properties of Sphagnum mosses have been reported by other researchers, which could aid in the protection of D. rotundifolia hibernacula. These results indicate that live Sphagnum moss is a better substrate for this species than milled peat, both for commercial production and for in situ conservation. This information can be vital to the survival and conservation of this species. Sphagnum bogs may protect and allow the expansion and re-establishment of D. rotundifolia.

Open Access: Yes

DOI: 10.1016/j.funbio.2025.101614

First report of Xanthomonas arboricola on oleander

László Palkovics Anita Végh Attila FODOR

Publication Name: Phytopathologia Mediterranea

Publication Date: 2025-01-01

Volume: 64

Issue: 1

Page Range: 101-108

Description:

Nerium oleander L is a long-lasting flowering vegetatively propagated ornamental plant of the Mediterranean region, where it is a major imported flowering pot plant. Only a few bacteria can infect it such as Pseudomonas savastanoi pv. nerii, Agrobacterium tumefaciens and Xylella fastidiosa. Between 2018 and 2022 we collected several infected plant parts in our country. In 2020 we observed atypical symptoms on the leaves and stems, which were not clearly similar to the known bacterial infection of oleander. In our work, we aimed to identify the pathogen. The isolates formed yellowcoloured bacterial colonies on King-B and on YDC agar, were Gram-negative, oxidase negative and induced hypersensitive reaction on tobacco leaves. The biochemical properties were determined by API 20E and API 50CH tests. Brown necrosis was observed on oleander leaves in a pathogenicity test. Multilocus sequence analysis was used for molecular identification of the pathogen. Three housekeeping genes (gyrB, fyuA and rpoD) were amplified. According to symptoms, colony morphology, biochemical features, pathogenicity and molecular methods, the pathogen was identified as Xanthomonas arboricola. This is the first report of the plant pathogenic Xanthomonas spp. on oleander.

Open Access: Yes

DOI: 10.36253/phyto-15575

Viral coat proteins decrease the gene silencing activity of cognate and heterologous viral suppressors

László Palkovics Katalin Nemes Réka Sáray Dóra Pinczés Katalin Salánki

Publication Name: Scientific Reports

Publication Date: 2024-12-01

Volume: 14

Issue: 1

Page Range: Unknown

Description:

Plant viruses have evolved different viral suppressors of RNA silencing (VSRs) to counteract RNA silencing which is a small RNA-mediated sequence-specific RNA degradation mechanism. Previous studies have already shown that the coat protein (CP) of cucumber mosaic virus (CMV) reduced RNA silencing suppression (RSS) activity of the VSR of CMV, the 2b protein. To demonstrate the universality of this CP-VSR interference, our study included three different viruses: CMV and peanut stunt virus (PSV) from the Bromoviridae, and plum pox virus (PPV) from the Potyviridae family. The RSS activity of the three VSRs (CMV 2b, PSV 2b, and PPV HC-Pro) was compared using Agrobacterium-mediated transient expression in Nicotiana benthamiana and the effect of CMV CP, PSV CP and PPV CP was validated on the RSS activity of their cognate and heterologous VSRs as well. Furthermore, the VSRs were also evaluated in PTGS suppressor-deficient CMV mutant (CMV NVE/10–12/AAA) virus-infected plants. The joint presence of CPs and VSRs resulted in decreased RSS activity in each combination, regardless of the origin of the two proteins, suggesting a universal role of the viral CPs in fine tuning of RSS. Interestingly the PSV CP elicited the strongest negative effect on the RSS activity of all three VSRs.

Open Access: Yes

DOI: 10.1038/s41598-024-81998-4

Investigation of viral diseases of garlic (Allium sativum L.), new primers for RT-PCR detection and diversity of garlic viruses in Hungary

László Palkovics János Ágoston Ádám Koczor János Ádám Katalin Salánki

Publication Name: Physiological and Molecular Plant Pathology

Publication Date: 2024-11-01

Volume: 134

Issue: Unknown

Page Range: Unknown

Description:

The study investigated the presence of potyviruses, carlaviruses, and allexiviruses in garlic samples, highlighting the impact of these viruses on garlic cultivation. No virus-free garlic was identified, with infections from at least one virus species observed in all samples. Notably, LYSV was detected in one sample, emphasizing the critical need for certified propagating material. Our study revealed the predominance of allexiviruses, particularly GarVD. Interestingly, no mixed carlavirus infections were detected. The results underline the risk of virus complexes, particularly when potyvirus infections occur alongside carla- or allexiviruses, exacerbating yield losses. The new primers we designed were successfully used, the usability of certain primers from earlier research has been confirmed, and new potential applications have been identified for some primers. In our study we have molecularly identified LYSV, GCLV, SLV, GarVB, GarVC and GarVD infected samples from Hungary, the presence of LYSV was confirmed with ELISA as well.

Open Access: Yes

DOI: 10.1016/j.pmpp.2024.102394

Biology, phylogenetic and evolutionary relations of Tradescantia mild mosaic virus isolates from Hungary

László Palkovics Réka Sáray János Ágoston Dóra Pinczés Asztéria Almási Katalin Salánki

Publication Name: Journal of Plant Pathology

Publication Date: 2024-08-01

Volume: 106

Issue: 3

Page Range: 1369-1374

Description:

In Western Transdanubia in 2018 and in Central-Hungary in 2022 spiderwort plants showed flower breaking symptoms and mild mosaic on the foliage, which indicated a potential virus infection. One gram of symptomatic leaf sample was collected at both locations. Potyvirus-specific ELISA tests demonstrated potyvirus infection. To identify the virus species, potyvirus-specific RT-PCR was carried out on the samples. In both samples specific PCR products were detected and cloned into pGEM®-T Easy vector. The nucleotide sequences of the inserts were determined by Sanger sequencing. BLASTn searches on the complete coat protein region of both isolates demonstrated more than 99.87% identity with Tradescantia mild mosaic virus (TraMMV; accession number OL584375). Koch postulates were fulfilled by sap inoculating seed grown spiderwort plants. Phylogenetic analyses of the TraMMV coat protein sequences revealed two distinct evolutionary lineages: a tropical subgroup with at least 97.84% identity within the group and temperate subgroup with at least 98.97% identity within the group. One major difference between the subgroups was in the triplet responsible for vector transmission. The isolates belonging to the tropical subgroup had DAG triplets, while the temperate subgroup had NAG triplets. The difference in the triplets could be caused by natural diversification, directional selection or disruptive selection. License: CC BY-NC-ND

Open Access: Yes

DOI: 10.1007/s42161-024-01661-9

First Report of Saffron Latent Virus in Crocus sativus from Hungary

László Palkovics Réka Sáray János Ágoston Dóra Pinczés Asztéria Almási Katalin Salánki

Publication Name: Plant Disease

Publication Date: 2024-02-01

Volume: 108

Issue: 2

Page Range: 540

Description:

No description provided

Open Access: Yes

DOI: 10.1094/PDIS-09-23-1765-PDN

Analysis of Potential Energy Transition Schemes in Hungary: from Natural Gas to Electricity

László Palkovics Csaba Gondola Tibor Gulyás

Publication Name: Chemical Engineering Transactions

Publication Date: 2024-01-01

Volume: 114

Issue: Unknown

Page Range: 871-876

Description:

Hungary, as a landlocked nation with limited raw material resources, faces significant challenges in ensuring a stable energy supply, necessitating extensive interconnectors with neighbouring countries for gas, oil, and electricity. While progress has been made, especially in electricity interconnections, the Russian-Ukrainian conflict and the EU’s decarbonisation goals for 2050 introduce new pressures on energy security. Hungary's energy trilemma—balancing access and affordability, environmental targets, and security—guides its strategy as it seeks an optimal energy mix. By 2050, energy demand is projected to hold steady at 210 TWh, though the current 65 % fossil fuel share, largely imported, highlights Hungary’s vulnerabilities (exposure to risks and insecurities in its energy supply). Goals include net-zero emissions, reduced foreign dependency, and manageable energy costs, with targets to reduce gas consumption to 4×109 m3 (1.5 ×109 m3) and ensure over 50 % of the energy mix is carbon-neutral electricity. The paper examines three key actions based on statistical data to achieve these targets: (a) reducing natural gas dependency, (b) boosting domestic alternative sources like local gas production and green solutions, and (c) enhancing energy system flexibility through regulation, storage, and generation. These strategies are assessed for their potential to satisfy the trilemma’s demands and provide a resilient path forward amidst evolving challenges.

Open Access: Yes

DOI: 10.3303/CET24114146

First report of Rhodococcus fascians causing leafy gall on Iberis sempervirens in Hungary

László Palkovics Zoltán Bozsó András Künstler János Ágoston Judit Kolozsváriné Nagy Ildikó Schwarczinger Dénes Dlauchy Lóránt Király József Fodor

Publication Name: Phytopathologia Mediterranea

Publication Date: 2024-01-01

Volume: 63

Issue: 3

Page Range: 465-473

Description:

In spring of 2023, leafy gall symptoms were detected on plants of evergreen candytuft (Iberis sempervirens ‘Pink Ice’) in Hungary. Bacteria isolated from gall-like tissues of short, stunted shoots, and showing a characteristic appearance on selective culture media were investigated using bacteriological and molecular methods, and phylogenetic analysis. Nucleotide sequences of the 16S rRNA gene, fasD and vicA genes were determined. Pathogenicity of selected isolates was confirmed on garden pea (Pisum sativum ‘Tristar’). Characterization of the investigated isolates indicated the presence of Rhodococcus fascians in I. sempervirens. This is the first report identifying the causal agent of leafy gall from this plant in Hungary.

Open Access: Yes

DOI: 10.36253/phyto-15357

Genetic variability of grapevine Pinot gris virus (GPGV) in an organically cultivated vineyard in Hungary

Tamás DEÁK Erzsébet SZATHMÁRY László Palkovics Réka Sáray Dóra Pinczés Asztéria Almási Katalin Salánki

Publication Name: Phytopathologia Mediterranea

Publication Date: 2024-01-01

Volume: 63

Issue: 2

Page Range: 179-190

Description:

Grapevine Pinot gris virus (GPGV) is a recently identified trichovirus infecting grapevines. Despite wide distribution, there is limited available information on epidemiology, transmission, and associated symptoms of grapevine leaf mottling and deformation. Occurrence and genetic diversity of GPGV variants were surveyed in an organically cultivated Hungarian vineyard that was planted between 1996 and 2014. Sequence analysis demonstrated the widespread presence and high variability of GPGV, and according to phylogenetic analyses, the Hungarian virus isolates were classified into three groups. Most of the identified variants clustered with the representative asymptomatic isolates, but all isolates from one grapevine cultivar grouped with representative isolates of clade B. Furthermore, one isolate clustered with representative isolates of clade C, and the identified clade C variant had previously undescribed polymorphisms.

Open Access: Yes

DOI: 10.36253/phyto-14492

Phylogenetic analysis of Plenodomus lingam and Plenodomus biglobosus isolates in Hungary

M. Petróczy László Palkovics Bianka Bagi

Publication Name: Journal of Plant Diseases and Protection

Publication Date: 2023-08-01

Volume: 130

Issue: 4

Page Range: 875-882

Description:

Blackleg (stem canker) of crucifers is a globally important disease caused by multiple genetic subclades of the fungi Plenodomuslingam (syn.: Leptosphaeria maculans) and Plenodomus biglobosus (syn.: Leptosphaeria biglobosa). In our study, we monitored the geographical distribution of these two pathogen species from rapeseed growing areas in Hungary. Multiplex PCR identified 48.7% of the isolates as Plenodomus biglobosus, which indicates the non-recent introduction of the pathogen into Hungary. In addition, multi-locus analysis revealed low genetic diversity within the species, as all isolates were clustered to the Plenodomuslingam ‘brassicae’ and Plenodomus biglobosus ‘brassicae’ subclades. The low genetic diversity of a population generally means reduced adaptation potential, which is essential information in breeding and in developing more effective management strategies.

Open Access: Yes

DOI: 10.1007/s41348-023-00720-0

First Report of Meadow Saffron Breaking Virus on Wild Colchicum autumnale from a Strictly Protected Natura2000 Site at a Hungarian National Park

László Palkovics Réka Sáray János Ágoston Dóra Pinczés Asztéria Almási Katalin Salánki

Publication Name: Plant Disease

Publication Date: 2023-06-01

Volume: 107

Issue: 6

Page Range: 1955

Description:

No description provided

Open Access: Yes

DOI: 10.1094/PDIS-08-22-1787-PDN

Thalia dealbata, a new host of sugarcane mosaic virus

László Palkovics Réka Sáray János Ágoston Dóra Pinczés Asztéria Almási Katalin Salánki

Publication Name: Journal of Plant Pathology

Publication Date: 2023-05-01

Volume: 105

Issue: 2

Page Range: 587-588

Description:

No description provided

Open Access: Yes

DOI: 10.1007/s42161-022-01295-9

Detection of ‘Candidatus Phythoplasma prunorum’ in Apricot Trees and its Associated Psyllid Samples

Márta Ladányi M. Petróczy László Palkovics Béla Pénzes Géza Nagy László Sándor Koncz János Ágoston Piroska Gyócsi József Fail

Publication Name: Agronomy

Publication Date: 2023-01-01

Volume: 13

Issue: 1

Page Range: Unknown

Description:

‘Candidatus Phytoplasma prunorum’ is causing ever increasing economic losses through the decline of apricot trees in European countries, e.g., Hungary. In this study, the pathogen was identified from plant tissues and insects by nested-PCR. The insect species were identified via morphology and molecular methods. The incidence of the pathogen was 29.6% in randomly selected apricot trees. Most of the infected trees with symptoms died within a year. These results show that phytoplasma is significantly present and causes damage in the investigated plantations. The only known insect vector of this phytoplasma is the plum psyllid, Cacopsylla pruni, which was regularly encountered in the sampled apricot orchards and in their surroundings. In a two-year study, several adults among the sampled specimens were observed to be infected by the pathogen. This observation further confirms the role of the plum psyllid in vectoring the phytoplasma. All the sampled plum psyllid adults belonged to the ‘B’ biotype. Besides C. pruni, Cacopsylla crataegi was abundant in the samples. Several adults of the latter species were also infected by the pathogen ‘Ca. Phytoplasma prunorum’. The rates of occurrence of this phytoplasma in male and female adults of the two psyllid species appeared to be similar. The examined C. crataegi individuals showed genetic differences from each other and from specimens included in a previous investigation.

Open Access: Yes

DOI: 10.3390/agronomy13010199

Brenneria nigrifluens Isolated from Aesculus hippocastanum L. Bark in Hungary

László Palkovics Anita Végh Imola Tenorio‐baigorria Gergely Botyánszki Rita Gyuris György Zsigó

Publication Name: Forests

Publication Date: 2022-02-01

Volume: 13

Issue: 2

Page Range: Unknown

Description:

In Hungary, from the beginning of the 19th century, horse‐chestnut trees have been planted widely and are popular ornamental trees in public parks, along streets, and in gardens. In the summer of 2015, longitudinal cracks on the trunk and branches and the intensive oozing of brown liquid were observed from a wound in a horse‐chestnut tree in a park in Budapest. Some years later, in 2018 and 2019, the same symptoms were found in trees in other locations in Budapest. Several bacteria were reported that induce similar symptoms, including cracks and cankers on the bark of trunks and branches and sticky, white, red, brown, or black oozing. These pathogens belong to the genera Brenneria and Lonsdalea. Bark and exudate samples were taken with the aim of identifying the causal agent by conventional and molecular methods. Our results confirmed that the bacteria isolated from Aesculus hippocastanum trees belong to the genus Brenneria and phylogenetic analysis of the 16S rRNA gene region proved to have the closest phylogenetic relation with the Brenneria nigrifluens strains.

Open Access: Yes

DOI: 10.3390/f13020227

First Report of Coniella granati Causing Leaf Spot of Pomegranate (Punica granatum) in Hungary

M. Petróczy László Palkovics A. Tóth L. Szendrei P. Salamon

Publication Name: Plant Disease

Publication Date: 2022-11-01

Volume: 106

Issue: 11

Page Range: 2995

Description:

No description provided

Open Access: Yes

DOI: 10.1094/PDIS-10-21-2230-PDN

Peanut stunt virus movement protein is the limiting factor in Capsicum annuum infection

László Palkovics Attila Fábián Dóra Pinczés Katalin Salánki

Publication Name: Virus Research

Publication Date: 2022-10-02

Volume: 319

Issue: Unknown

Page Range: Unknown

Description:

Cucumber mosaic virus (CMV) is one of the most devastating plant viruses, with more than 1,200 species of host plants. The host range and economic importance of peanut stunt virus (PSV) are mostly limited to legumes, despite the similar taxonomy and genome structure with CMV. Since no data are available on the background of the limited host range of PSV, RNA 3 recombinant and reassortant viruses were generated (C12P3, P12C3, C12CP3, C12PC3, C12PΔC3) to study their infection phenotype on a common host (Nicotiana benthamiana) and on a selective host (Capsicum annuum cv. Brody). The PSV movement protein (MP) was not able to function with the coat protein (CP) of CMV unless the C-terminal 42 amino acids were deleted from the PSV MP. As a result of the inoculation experiments, MP was considered the protein influencing symptom phenotypes on N. benthamiana and responsible for the host range difference on the pepper. Since plasmodesmata (PD) localization of viral MPs is essential for cell-to-cell movement, subcellular localization of GFP-tagged MPs (CMV-MP-eGFP, PSV-MP-eGFP) was observed. In the case of CMV-MP-eGFP, clear colocalization with PD was detected in both hosts, but PSV-MP-eGFP was not tightly connected to the PD in N. benthamiana and barely localized to the PD in C. annuum epidermal cells. Measuring Pearson correlation coefficients (PCCs) also supported the visual observation.

Open Access: Yes

DOI: 10.1016/j.virusres.2022.198879

First report of Serratia marcescens from oleander in Hungary

László Palkovics Anita Végh Attila Fodor

Publication Name: Phytopathologia Mediterranea

Publication Date: 2022-01-01

Volume: 61

Issue: 2

Page Range: 311-317

Description:

Oleander (Nerium oleander L.) is a popular woody ornamental plant, often used for decorating public areas, terraces and gardens. Many diseases may decrease in the ornamental value of these plantings. Between 2018 and 2020, plant pathogenic bacteria of oleander were examined, and many samples of infected plants were collected from different sites in Hungary. Two non-pigmented Serratia marcescens isolates were identified from oleander by classical and molecular methods. The isolates caused necrotic lesions on oleander leaves. Serratia marcescens is known as an opportunistic mammal or plant pathogen, but non-pathogenic strains are known to be useful biological control agents or plant growth-promoting bacteria. This is the first report of the plant pathogen S. marcescens from oleander, and the first identification of the bacterium in Hungary.

Open Access: Yes

DOI: 10.36253/phyto-13354

Sternbergia lutea, a new host of Narcissus late season yellows virus

László Palkovics János Ágoston Asztéria Almási Katalin Salánki

Publication Name: Phytopathologia Mediterranea

Publication Date: 2021-01-01

Volume: 60

Issue: 3

Page Range: 403-407

Description:

In autumn 2017, autumn daffodil plants with yellow-green stripes on the leaves were observed at a botanical garden in Budapest, Hungary. Indicator plants wereinoculated, but symptoms did not develop. RT-PCR tests of the indicator plants werealso negative for the viruses. Potyvirus specific ACP-ELISA and RT-PCR were carriedout on the symptomatic S. lutea leaf samples. RT-PCR with universal potyvirusprimers resulted in one, approx. 1700 base pair PCR product. Phylogenetic analysis ofthe nucleotide sequence of the coat protein demonstrated 98.78-99.51% identity withthree Japanese isolates of Narcissus late season yellows virus. While unidentified potyvirusinfection of autumn daffodil has been previously reported, sequence data havenot been published. Therefore, this is the first report of Sternbergia lutea as a host ofNarcissus late season yellows virus

Open Access: Yes

DOI: 10.36253/phyto-12709