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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. [ABSTRACT FROM AUTHOR]

'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. [ABSTRACT FROM AUTHOR]

In autumn 2017, autumn daffodil plants with yellow-green stripes on the leaves were observed at a botanical garden in Budapest, Hungary. Indicator plants were inoculated, but symptoms did not develop. RT-PCR tests of the indicator plants were also negative for the viruses. Potyvirus specific ACP-ELISA and RT-PCR were carried out on the symptomatic S. lutea leaf samples. RT-PCR with universal potyvirus primers resulted in one, approx. 1700 base pair PCR product. Phylogenetic analysis of the nucleotide sequence of the coat protein demonstrated 98.78-99.51% identity with three Japanese isolates of Narcissus late season yellows virus. While unidentified potyvirus infection of autumn daffodil has been previously reported, sequence data have not been published. Therefore, this is the first report of Sternbergia lutea as a host of Narcissus late season yellows virus. [ABSTRACT FROM AUTHOR]

The commonly occurring blackleg is an economically important disease in oilseed rape cultivation. This disease is caused by a complex of two closely related species, Plenodomus lingam and P. biglobosus. To date, only P. lingam (syn.: Leptosphaeria maculans) has been known in Hungary as the cause of blackleg in oilseed rape crops. The present study aimed to determine if P. biglobosus (syn.: Leptosphaeria biglobosa) was present in Hungary. The two fungus pathogens are difficult to distinguish using conventional morphological criteria. Reliable detection and differentiation of the two species can only be achieved using molecular methods. This is the first report describing the pathogen, P. biglobosus, in Hungary. [ABSTRACT FROM AUTHOR]

During July 2012, a severe unusual disease symptom was observed on young shoots on apricot (Prunus armeniaca 10/13 hybrid) in the city of Pomáz, near Budapest. The naturally infected shoots showed typical symptoms of fire blight including terminal shoots with brown to black necrotic lesions. Symptoms were the same as fire blight symptoms reported from other hosts and locations. The first occurrence of fire blight on an apricot tree in Europe was recorded in Czech Republic in 2011. Samples of the leaves and shoots with symptoms were macerated and spread on King's medium B. After 24 hours of incubation at 26 °C, bacteria morphologically similar to E. amylovora were detected. Isolate induced hypersensitive reaction on tobacco (Nicotiana tabacum L. 'White Burley') leaves. Biochemical test was also used for identification, and the result of API 20E kit (Biomérieux, Marcy l'Etoile, France), demonstrate that the bacterium belongs to Enterobacteriaceae family. A pathogenicity tests were positive on young apricot shoots and immature fruits. For molecular identification of the pathogen the 16S rDNA region was amplified from isolate Ea-ApricotPo1 with a general bacterial primer pair (63f forward and 1389r reverse). The PCR products were cloned into a pGEM T-Easy plasmid vector (Promega, Madison, WI USA) and were transformed into Escherichia coli DH5α cells. A recombinant plasmid (2A2.5) was sequenced by M13 forward and reverse primers. The sequence was deposited in GenBank (Accession No. HF546214) and showed 99-100% sequence homology with a number of E. amylovora isolates, including type strain FN666575 with 100% similarity. On the basis of the symptoms, colony morphology, biochemical tests, and 16S rDNA sequence homology, the pathogen was identified as E. amylovora. This is a first record of a natural outbreak of fire blight on apricot in Hungary. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Plum pox virus (PPV) isolates were collected in Hungary from plum varieties. PCR targeting the 3′ genomic region resulted in a shorter PCR product in the case of the B1298 isolate bearing a 135-nucleotide deletion in frame in the N-terminal part of the coat protein (CP). The isolate was aphid-transmissible and the virion diameter was reduced compared to PPV-SK68. Detectability of this isolate by Western blot varied according to the antibody used. Integration of the deleted CP gene into an infectious PPV clone had no effect on infectivity and symptomatology. In competition experiments, B1298 had a considerable advantage in virus accumulation. [ABSTRACT FROM AUTHOR]

Tulip breaking is economically the most important viral disease of modern-day tulip growing. It is characterized by irregular flame and feather-like patterns in the flowers and mosaic on the foliage. Thirty-two leaf samples were collected from cultivated tulip plants showing tulip breaking syndrome from Hungary in 2017 and 2018. Virus identification was performed by serological (ELISA) and molecular (RT-PCR) methods. All samples proved to be infected with a potyvirus and evidence was provided that three potyvirus species could be identified in the samples: Lily mottle virus (LMoV), Tulip breaking virus (TBV) and Rembrandt tulip-breaking virus (ReTBV). Recombination prediction accomplished with Recombination Detection Program (RDP) v4.98 revealed potential intraspecies recombination in the case of TBV and LMoV. Phylogenetic analyses of the coat protein (CP) regions proved the monophyletic origin of these viruses and verified them as three different species according to current International Committee on Taxonomy of Viruses (ICTV) species demarcation criteria. Based on these results, we analyzed taxonomic relations concerning potyviruses associated with tulip breaking syndrome. We propose the elevation of ReTBV to species level, and emergence of two new subgroups in ReTBV. [ABSTRACT FROM AUTHOR]

Keywords: Zantedeschia; Konjak mosaic virus; Zantedeschia mosaic virus; Potyvirus; Hungary 2 Lesemann D-E, Winter S (2002) Konjac mosaic virus, dasheen mosaic virus and unkown potyviruses infecting Zantedeschia spp. and other cultivated Araceae. Zantedeschia, Konjak mosaic virus, Zantedeschia mosaic virus, Potyvirus, Hungary. [Extracted from the article]

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. • Garlic is vulnerable to infections from Potyvirus , Carlavirus and Allexivirus genera. • Phylogenetic analyses revealed close genetic relationships among garlic virus isolates from different regions. • New primers have been designed for RT-PCR detection of garlic viruses. • The RT-PCR results and the phylogenetic analysis showed that all samples were infected with at least one garlic virus. [ABSTRACT FROM AUTHOR]

Resurgence of Tomato spotted wilt virus (TSWV) worldwide as well as in Hungary causing heavy economic losses directed the attention to the factors contributing to the outbreak of this serious epidemics. The introgression of Tsw resistance gene into various pepper cultivars seemed to solve TSWV control, but widely used resistant pepper cultivars bearing the same, unique resistance locus evoked the rapid emergence of resistance-breaking (RB) TSWV strains. In Hungary, the sporadic appearance of RB strains in pepper-producing region was first observed in 2010-2011, but in 2012 it was detected frequently. Previously, the non-structural protein (NSs) encoded by small RNA (S RNA) of TSWV was verified as the avirulence factor for Tsw resistance, therefore we analyzed the S RNA of the Hungarian RB and wild type (WT) isolates and compared to previously analyzed TSWV strains with RB properties from different geographical origins. Phylogenetic analysis demonstrated that the different RB strains had the closest relationship with the local WT isolates and there is no conserved mutation present in all the NSs genes of RB isolates from different geographical origins. According to these results, we concluded that the RB isolates evolved separately in geographic point of view, and also according to the RB mechanism.

Wheat dwarf virus (WDV) is the most ubiquitous virus in cereals causing huge losses in both Hungary and Ukraine. The presence of barley-and wheat-adapted strains has been confirmed, suggesting that the barley strain is restricted to barley, while the wheat strain is present in both wheat and barley plants. Five WDV isolates from wheat plants sampled in Hungary and Ukraine were sequenced and compared with known WDV isolates from GenBank. Four WDV isolates belonged to the wheat strain. Our results indicate that WDV-Odessa is an isolate of special interest since it has originated from wheat, but belongs to the barley-adapted strain, providing novel data on WDV biology and raising issues of pathogen epidemiology.

Zucchini yellow mosaic virus (ZYMV) has emerged as an important pathogen of cucurbits within the last few years in Hungary. The Hungarian isolates show a high biological variability, have specific nucleotide and amino acid sequences in the N-terminal region of coat protein and form a distinct branch in the phylogenetic tree. The virus is spread very efficiently in the field by several aphid species in a non-persistent manner. It can be transmitted by seed in holl-less seeded oil pumpkin (Cucurbita pepo (L) var Styriaca), although at a very low rate. Three isolates from seed transmission assay experiments were chosen and their nucleotide sequences of coat proteins have been compared with the available CP sequences of ZYMV. According to the sequence analysis, the Hungarian isolates belong to the Central European branch in the phylogenetic tree and, together with the ZYMV isolates from Austria and Slovenia, share specific amino acids at positions 16, 17, 27 and 37 which are characteristic only to these isolates. The phylogenetic tree suggests the common origin of distantly distributed isolates which can be attributed to widespread seed transmission.