Using machine learning algorithms and techniques for defining the impact of affective temperament types, content search and activities on the internet on the development of problematic internet use in adolescents' population.

Background: By using algorithms and Machine Learning - ML techniques, the aim of this research was to determine the impact of the following factors on the development of Problematic Internet Use (PIU): sociodemographic factors, the intensity of using the Internet, different contents accessed on the Internet by adolescents, adolescents' online activities, life habits and different affective temperament types. Methods: Sample included 2,113 adolescents. The following instruments were used: questionnaire about: socio-demographic characteristics, intensity of the Internet use, content categories and online activities on the Internet; Facebook (FB) usage and life habits; The Internet Use Disorder Scale (IUDS). Based on their scores on the scale, subjects were divided into two groups - with or without PIU; Temperament Evaluation of Memphis, Pisa, Paris, and San Diego scale for adolescents (A-TEMPS-A). Results: Various ML classification models on our data set were trained. Binary classification models were created (class-label attribute was PIU value). Models hyperparameters were optimized using grid search method and models were validated using k-fold cross-validation technique. Random forest was the model with the best overall results and the time spent on FB and the cyclothymic temperament were variables of highest importance for these model. We also applied the ML techniques Lasso and ElasticNet. The three most important variables for the development of PIU with both techniques were: cyclothymic temperament, the longer use of the Internet and the desire to use the Internet more than at present time. Group of variables having a protective effect (regarding the prevention of the development of PIU) was found with both techniques. The three most important were: achievement, search for contents related to art and culture and hyperthymic temperament. Next, 34 important variables that explain 0.76% of variance were detected using the genetic algorithms. Finally, the binary classification model (with or without PIU) with the best characteristics was trained using artificial neural network. Conclusion: Variables related to the temporal determinants of Internet usage, cyclothymic temperament, the desire for increased Internet usage, anxious and irritable temperament, on line gaming, pornography, and some variables related to FB usage consistently appear as important variables for the development of PIU.

Diet prevents the expansion of segmented filamentous bacteria and ileo-colonic inflammation in a model of Crohn's disease.

BACKGROUND: Crohn's disease (CD) is associated with changes in the microbiota, and murine models of CD-like ileo-colonic inflammation depend on the presence of microbial triggers. Increased abundance of unknown Clostridiales and the microscopic detection of filamentous structures close to the epithelium of Tnf ΔARE mice, a mouse model of CD-like ileitis pointed towards segmented filamentous bacteria (SFB), a commensal mucosal adherent bacterium involved in ileal inflammation. RESULTS: We show that the abundance of SFB strongly correlates with the severity of CD-like ileal inflammation in two mouse models of ileal inflammation, including Tnf ΔARE and SAMP/Yit mice. SFB mono-colonization of germ-free Tnf ΔARE mice confirmed the causal link and resulted in severe ileo-colonic inflammation, characterized by elevated tissue levels of Tnf and Il-17A, neutrophil infiltration and loss of Paneth and goblet cell function. Co-colonization of SFB in human-microbiota associated Tnf ΔARE mice confirmed that SFB presence is indispensable for disease development. Screening of 468 ileal and colonic mucosal biopsies from adult and pediatric IBD patients, using previously published and newly designed human SFB-specific primer sets, showed no presence of SFB in human tissue samples, suggesting a species-specific functionality of the pathobiont. Simulating the human relevant therapeutic effect of exclusive enteral nutrition (EEN), EEN-like purified diet antagonized SFB colonization and prevented disease development in Tnf ΔARE mice, providing functional evidence for the protective mechanism of diet in modulating microbiota-dependent inflammation in IBD. CONCLUSIONS: We identified a novel pathogenic role of SFB in driving severe CD-like ileo-colonic inflammation characterized by loss of Paneth and goblet cell functions in Tnf ΔARE mice. A purified diet antagonized SFB colonization and prevented disease development in Tnf ΔARE mice in contrast to a fiber-containing chow diet, clearly demonstrating the important role of diet in modulating a novel IBD-relevant pathobiont and supporting a direct link between diet and microbial communities in mediating protective functions. Video Abstract.

Symptomatology, (Co)occurrence and Differential Diagnostic PCR Identification of 'Ca. Phytoplasma solani' and 'Ca. Phytoplasma convolvuli' in Field Bindweed.

Field bindweed (Convolvulus arvensis) is one of the major natural plant hosts and reservoirs of 'Candidatus Phytoplasma solani' ('Ca. P. solani'), the causal agent of plant diseases in diverse agricultural crops, including Bois noir (BN) disease of grapevine. Phylogenetically, the most closely related phytoplasma to 'Ca. P. solani', the 'Ca. P. convolvuli', induces disease in field bindweed that is known by its symptoms as bindweed yellows (BY). The occurrence, coinfection and symptoms association of the two phytoplasmas in shared host plants were the subject of this study. Specific primers for the amplification of the elongation factor Tu gene (tuf) were developed for the identification of 'Ca. P. convolvuli' (by conventional nested PCR), as well as primers for simultaneous detection of 'Ca. P. solani' and 'Ca. P. convolvuli' by duplex SYBR Green real-time PCR. Among symptomatic bindweed plants, 25 and 41% were infected with a single phytoplasma species, 'Ca. P. solani' and 'Ca. P. convolvuli', respectively, while 34% were infected with both phytoplasmas. None of the non-symptomatic control plants carried phytoplasma, while non-symptomatic plants from our previous epidemiological studies in BN-affected vineyards were confirmed to be infected solely with 'Ca. P. solani'. Stamp gene typing revealed Rqg50 and Rqg31 'Ca. P. solani' genotypes in plants coinfected with 'Ca. P. convolvuli', while three diverse genotypes (Rqg50, GGY and Rpm35) were identified in a single locality with symptomatic bindweeds infected solely with 'Ca. P. solani'. Variations in symptoms and their association with each of the phytoplasmas are described and documented. The symptom of bushy appearance could be single out as specific for 'Ca. P. convolvuli' infection, while occurrence of 'Ca. P. solani' could not be unequivocally associated with specific alterations in infected bindweeds. The results are discussed in the context of the epidemiological and ecological complexity of 'Ca. P. solani'-induced diseases and the relationship between the two phytoplasma relatives in shared host plant.

Internet use during coronavirus disease of 2019 pandemic: Psychiatric history and sociodemographics as predictors.

Coronavirus disease of 2019 (COVID-19) pandemic and related containment measures have grossly affected the daily living and created a need for alternative ways of social communication and entertainment. The aim of this study was to explore the use of various Internet contents depending on sociodemographics and on psychiatric history of participants. This cross-sectional, population-based study is a part of a wider international multicenter study. A total of 1275 participants across Serbia (71.1% of females; average age = 41.81 ± 12.52 years) were recruited using two-level chain-referral sampling method. The participants filled in an anonymous online questionnaire that included questions on sociodemographic data, psychiatric history, and various aspects of increased Internet use since the pandemic. The data were analyzed using a series of multiple logistic regressions. About two-thirds of the sample reported using Internet more during the pandemic. All of the tested regression models, apart from models predicting browsing religion and travel/tourism, were significant, explaining from about 2% (for the contents specific for COVID-19) up to 34.4% (for the sexual content) of variance of use. Reporting a previously diagnosed psychiatric disorder was a significant predictor of greater Instagram use and browsing sexual and sport-related content since the pandemic. To the best of our knowledge, the study is the first to report on the relationship between Internet using and mental health, during COVID-19 pandemic, in the Balkan region. The findings showed various patterns of the increased use of Internet contents since the pandemic referring to both potentially positive and negative Internet influences.

When a Palearctic bacterium meets a Nearctic insect vector: Genetic and ecological insights into the emergence of the grapevine Flavescence dorée epidemics in Europe.

Flavescence dorée (FD) is a European quarantine grapevine disease transmitted by the Deltocephalinae leafhopper Scaphoideus titanus. Whereas this vector had been introduced from North America, the possible European origin of FD phytoplasma needed to be challenged and correlated with ecological and genetic drivers of FD emergence. For that purpose, a survey of genetic diversity of these phytoplasmas in grapevines, S. titanus, black alders, alder leafhoppers and clematis were conducted in five European countries. Out of 132 map genotypes, only 11 were associated to FD outbreaks, three were detected in clematis, whereas 127 were detected in alder trees, alder leafhoppers or in grapevines out of FD outbreaks. Most of the alder trees were found infected, including 8% with FD genotypes M6, M38 and M50, also present in alders neighboring FD-free vineyards and vineyard-free areas. The Macropsinae Oncopsis alni could transmit genotypes unable to achieve transmission by S. titanus, while the Deltocephalinae Allygus spp. and Orientus ishidae transmitted M38 and M50 that proved to be compatible with S. titanus. Variability of vmpA and vmpB adhesin-like genes clearly discriminated 3 genetic clusters. Cluster Vmp-I grouped genotypes only transmitted by O. alni, while clusters Vmp-II and -III grouped genotypes transmitted by Deltocephalinae leafhoppers. Interestingly, adhesin repeated domains evolved independently in cluster Vmp-I, whereas in clusters Vmp-II and-III showed recent duplications. Latex beads coated with various ratio of VmpA of clusters II and I, showed that cluster II VmpA promoted enhanced adhesion to the Deltocephalinae Euscelidius variegatus epithelial cells and were better retained in both E. variegatus and S. titanus midguts. Our data demonstrate that most FD phytoplasmas are endemic to European alders. Their emergence as grapevine epidemic pathogens appeared restricted to some genetic variants pre-existing in alders, whose compatibility to S. titanus correlates with different vmp gene sequences and VmpA binding properties.

The Development of Temperament Evaluation of Memphis, Pisa, Paris, and San Diego - Auto-questionnaire for Adolescents (A-TEMPS-A) in a Serbian Sample.

BACKGROUND: Previous studies suggest that temperament features of adolescents may be good predictors of the development of future psychopathology in this population. The aim of the study was to adapt the content and validate the psychometric properties of the Temperament Evaluation of Memphis, Pisa, Paris, and San Diego - Auto-questionnaire in a sample of Serbian adolescents. SUBJECTS AND METHODS: The sample included 2113 adolescents, 56% girls and 44% boys, average age 16.73±0.47, attending 48 Serbian secondary schools. The base for the development of this scale included Serbian standardised versions as well as the TEMPS-I, Interview version. RESULTS: The final scale is comprised of 36 items, with six factors (depressive, cyclothymic, hyperthymic, irritable, and anxious-cognitive/somatic) explaining 39.9% of the total variance, the internal consistency coefficient α=0.77, and the average test-retest coefficient (rho=0.84). The correlations among the temperaments ranged from weak to moderate, with the highest positive correlations between the depressive, cyclothymic and anxious scales. The highest values were detected on hyperthymic and the lowest on depressive temperament. Significantly higher scores of depressive, cyclothymic and anxious temperaments were detected in girls, whereas boys had higher scores on the hyperthymic scale. CONCLUSIONS: The scale has shown good psychometric properties, which encourages its further use in adolescent population. The results show certain specific features of this population, such as higher scores on all temperament types than the ones in student and adult population and a tendency of socially desirable answers.

Resource allocation in response to herbivory and gall formation in Linaria vulgaris.

Trehalose and its precursor, trehalose 6-phosphate (T6P), are essential regulators of plant response to abiotic and biotic stress. Here we used the specific host-insect interaction between Linaria vulgaris (Plantaginaceae) and stem-galling weevil, Rhinusa pilosa (Mecinini, Curculionidae) with the aim to distinguish carbohydrate allocation patterns in response to herbivory, gall formation (G1, 24 h after oviposition), and gall development (G2, 7 days after oviposition) under controlled conditions. The hypothesis is that herbivory and galling induce distinct responses in both leaves and stems, and that shifts in carbon allocations are regulated by signaling sugars. Systemic response to herbivory was accumulation of T6P and maltose. The main feature of G1 in the stems was accumulation of trehalose, accompanied by increased T6P, turanose and glucose content, oppositely to the leaves. In G2, galls had 3-folds higher weight than controls, with further accumulation of fructose, glucose, turanose, and total water-insoluble carbohydrates (TIC), while the sucrose/hexose ratio decreased. Analysis of fast chlorophyll fluorescence kinetic (OJIP) transients in G2 showed a slight decrease in quantum yield of electron transport flux from QA to QB, and towards photosystem I acceptor side, correlated with the decreased content of photosynthetic pigments and hexoses accumulation. Redistribution of photosynthates, and accumulation of T6P were induced in response to herbivory, indicating its signaling role. The results support the hypothesis that R. pilosa can induce plant reprogramming towards the accumulation of beneficial carbohydrates in developing gall by mechanisms which include both T6P and trehalose.

Lignin-Degrading Abilities of Novel Autochthonous FungalIsolates Trametes hirsuta F13 and Stereum gausapatum F28.

The aim of this research is to isolate and identify fungi with high lignin-degrading abilities that are autochthonous to southern Serbian region. Two novel fungal isolates identified as Trametes hirsuta F13 and Stereum gausapatum F28 were selected to assess their ligninolytic enzyme activities and the efficiency of lignin removal from beech wood sawdust. Obtained results show that both isolates are good sources of industrially valuable enzymes with a potential for application in various biotechnological and industrial processes. Both isolates showed laccase, manganese-dependent peroxidase, and versatile peroxidase activities, while only S. gausapatum F28 had lignin peroxidase activity. This is the first record of the ability of S. gausapatum species to produce lignin peroxidase. T. hirsuta F13 showed higher laccase activity than S. gausapatum F28, while S. gausapatum F28 had higher manganese peroxidase activity. Also, T. hirsuta F13 exhibited much higher laccase activity under submerged cultivation conditions than solid-state cultivation conditions, which is rare for fungi. This is important for industrial processes since the submerged fermentation is a dominant technique in industry. The test of the efficiency of lignin removal showed that both isolates are efficient lignin decomposers. After five weeks of incubation on beech wood sawdust, the total lignin losses were 33.84% with T. hirsuta F13 and 28.8% with S. gausapatum F28.

Biocontrol and plant stimulating potential of novel strain Bacillus sp. PPM3 isolated from marine sediment.

In the current study, the biocontrol potential of a novel strain Bacillus sp. PPM3 isolated from marine sediment from the Red Sea in Hurghada, Egypt is recognized. This novel strain was selected out of 32 isolates based on its ability to suppress the growth of four plant pathogenic fungi: Aspergillus flavus, Fusarium graminearum, Mucor sp. and Alternaria sp. The new marine strain was identified and characterized by phenotypic and molecular approaches. The culture filtrate of Bacillus sp. PPM3 suppressed the growth and spore germination of all tested fungi in vitro with the highest value of inhibition reported for Mucor sp. (97.5%). The antifungal effect of the culture filtrate from the strain PPM3 was due to production of highly stable secondary metabolites resistant to extreme pH, temperature and enzymatic treatments. A PCR analysis confirmed the expression of genes involved in the synthesis of antifungal lipopeptides: iturin, bacillomycin D, mycosubtilin and surfactin. In a greenhouse experiment strain PPM3 effectively reduced disease incidence of F. graminearum in maize plants and displayed additional plant growth stimulating effect. The results show that novel marine strain PPM3 could have a potential in commercial application as biocontrol agent for treatment of various plant diseases caused by soil-borne and postharvest pathogenic fungi.

Widespread plant specialization in the polyphagous planthopper Hyalesthes obsoletus (Cixiidae), a major vector of stolbur phytoplasma: Evidence of cryptic speciation.

The stolbur phytoplasma vector Hyalesthes obsoletus is generally considered as a polyphagous species associated with numerous wild and cultivated plants. However, recent research in southeastern Europe, the distribution centre of H. obsoletus and the area of most stolbur-inflicted crop diseases, points toward specific host-plant associations of the vector, indicating specific vector-based transmission routes. Here, we study the specificity of populations associated with four host-plants using mitochondrial and nuclear genetic markers, and we evaluate the evolution of host-shifts in H. obsoletus. Host-plant use was confirmed for Convolvulus arvensis, Urtica dioica, Vitex agnus-castus and Crepis foetida. Mitochondrial genetic analysis showed sympatric occurrence of three phylogenetic lineages that were ecologically delineated by host-plant preference, but were morphologically inseparable. Nuclear data supported the existence of three genetic groups (Evanno's ΔK(3) = 803.72) with average genetic membership probabilities > 90%. While populations associated with C. arvensis and U. dioica form a homogenous group, populations affiliated with V. agnus-castus and C. foetida constitute two independent plant-associated lineages. The geographical signal permeating the surveyed populations indicated complex diversification processes associated with host-plant selection and likely derived from post-glacial refugia in the eastern Mediterranean. This study provides evidence for cryptic species diversification within H. obsoletus sensu lato: i) consistent mitochondrial differentiation (1.1-1.5%) among host-associated populations in syntopy and in geographically distant areas, ii) nuclear genetic variance supporting mitochondrial data, and iii) average mitochondrial genetic distances among host-associated meta-populations are comparable to the most closely related, morphologically distinguishable species, i.e., Hyalesthes thracicus (2.1-3.3%).

Divergent evolution of life span associated with mitochondrial DNA evolution.

Mitochondria play a key role in ageing. The pursuit of genes that regulate variation in life span and ageing have shown that several nuclear-encoded mitochondrial genes are important. However, the role of mitochondrial encoded genes (mtDNA) is more controversial and our appreciation of the role of mtDNA for the evolution of life span is limited. We use replicated lines of seed beetles that have been artificially selected for long or short life for >190 generations, now showing dramatic phenotypic differences, to test for a possible role of mtDNA in the divergent evolution of ageing and life span. We show that these divergent selection regimes led to the evolution of significantly different mtDNA haplotype frequencies. Selection for a long life and late reproduction generated positive selection for one specific haplotype, which was fixed in most such lines. In contrast, selection for reproduction early in life led to both positive selection as well as negative frequency-dependent selection on two different haplotypes, which were both present in all such lines. Our findings suggest that the evolution of life span was in part mediated by mtDNA, providing support for the emerging general tenet that adaptive evolution of life-history syndromes may involve mtDNA.

Morphology versus DNA barcoding: two sides of the same coin. A case study of Ceutorhynchus erysimi and C. contractus identification.

Genotyping of 2 well-known weevil species from the genus Ceutorhynchus (Coleoptera: Curculionidae) distributed in west Palearctic, C. erysimi and C. contractus, revealed phenotype versus genotype inconsistencies in a set of 56 specimens (25 C. erysimi and 31 C. contractus) collected from 25 locations in Serbia and Montenegro. An analysis of the mitochondrial cytochrome oxidase subunit I gene (COI), widely used as a barcoding region, and a nuclear gene, elongation factor-1α (EF-1α), revealed stable genetic divergence among these species. The average uncorrected pairwise distances for the COI and EF-1α genes were 3.8%, and 1.3%, respectively, indicating 2 genetically well-segregated species. However, the genetic data were not congruent with the phenotypic characteristics of the studied specimens. In the first place, C. erysimi genotypes were attached to specimens with phenotypic characteristics of C. contractus. Species-specific PCR-RFLP assays for the barcoding gene COI were applied for the molecular identification of 101 additional specimens of both morphospecies (33 C. erysimi and 68 C. contractus) and were found to confirm this incongruity. The discrepancy between the genetic and morphological data raises the question of the accuracy of using a barcoding approach, as it may result in misleading conclusions about the taxonomic position of the studied organism. Additionally, the typological species concept shows considerable weakness when genetic data are not supported with phenotypic characteristics as in case of asymmetric introgression, which may cause certain problems, especially in applied studies such as biological control programs in which the biological properties of the studied organisms are the main focus.

Effects of hormone replacement therapy on depressive and anxiety symptoms after oophorectomy.

AIM: To assess the effect of hormone replacement therapy on postoperative depression and anxiety symptoms. METHODS: In observational prospective study 80 women divided into two groups were evaluated: women who received estrogen and androgen replacement therapy after hysterectomy with bilateral oophorectomy before onset of menopause (35-45 years old) and a control group that consisted of perimenipausal women (45-55 years old). Hormone replacement therapy began one week after surgery. The severity of depression and anxiety was evaluated through the use of Hamilton Depression Rating Scale and Hamilton Anxiety Rating Scale. Subjects from the study group were interviewed right after the surgical treatment, one, two and three months later. Subjects from the control group were interviewed only once. RESULTS: The women who underwent surgery had a statistically significantly higher score in Hamilton Depression Scale (p les than 0.001) and Hamilton Anxiety Scale (p=0.002) compared to the control perimenopausal women. There was a significant reduction of depressive and anxiety symptoms during hormone replacement therapy. Statistically significant difference in depressive score was found immediately after one month of hormone replacement therapy (first week/one month later: p=0.0057). Statistically significant difference in anxiety score appeared three months after the introduction of hormone therapy (first week/one month later: p=0.309; first week/two months later: p=0.046; first week/three months later: p les than 0.001). Level of serum luteinizing hormone was in correlation with depressive and anxiety score. CONCLUSION: Estrogen-androgen replacement therapy may reduce the risk of psychiatric disorders developing in women with bilateral oophorectomy (indication for hysterectomy with oophorectomy was leiomyomata uteri).

Validation of the Temps-A in university student population in Serbia.

BACKGROUND AND AIMS: The TEMPS-A scale is a self-evaluation measure which assesses five affective temperaments. This study is a comparative analysis of affective temperament types in different educational fields, and the first validation of the Serbian version of the TEMPS-A. METHODS: The TEMPS-A questionnaire has been adapted following the translation-back translation methodology from English to Serbian. It was then administered to 770 undergraduate students from eight different faculties. RESULTS: Five factors were extracted through Principal Component Analysis (Varimax rotation), each including ten items with loadings above 0.40. The internal consistency of this abbreviated 50-item scale was α=0.77 and the average test-retest coefficient (rho=0.82) indicates a stable reliability. The correlations among the temperaments ranged from weak to moderate, with the highest positive correlations obtained between the depressive and cyclothymic, and, depressive and anxious scales. The highest score was detected among the hyperthymic (0.64) and lowest among the depressive temperament (0.15). The male participants attained significantly higher scores for the hyperthymic temperament, while female scored significantly higher on the depressive and anxious temperaments. The students of physical education showed significantly lower results on the depressive and anxious subscales and higher on the hyperthymic, in comparison to other educational fields. LIMITATIONS: The student sample is not representative of the general population, therefore further investigation in older population would be necessary for the evaluation of norms in additional age categories. The external validation with other personality scales has not been the subject of this research, but will be a part of some future studies. CONCLUSIONS: The Serbian 50-item version of the TEMPS-A showed good overall internal consistency and reliability, and the results generally cohere with those from previously validated versions in other languages.

[Differential diagnosis problem of pulmonary changes in ulcerative colitis].

INTRODUCTION: Inflammatory intestinal diseases are often accompanied with extraintestinal and even pulmonary manifesStations. The treatment of these intestinal diseases includes sulphasalazine and mesalazine, which may have undesirable allergic and other side effects, including hypersensitive pneumonitis. CASE REPORT: Having performed colonoscopy due to abdominal pains and mushy stools, the diagnosis of ulcerous colitis was established in a 20-year-old female patient and the treatment with mesalazine initiated. However, the patient developed slimy and bloody stools, slightly increased body temperature, dry cough and bilateral lung lesions. The bronchological exploration established interstitial and organizing pneumonia. Despite the treatment with antibiotics, corticosteroids and mesalazine, dry cough, fever and bloody stools persisted, accompanied with bilateral inhomogeneous lesions of the pulmonary parenchyma. Upon discontinuation of the treatment with mesalazine, clinical symptoms and pulmonary lesions disappeared. CONCLUSION: The differential diagnosis of pulmonary lesions in patients with ulcerous colitis may be a problem. In the reported case, pulmonary lesions were interpreted as interstitial pneumonitis accompanying ulcerous colitis. However, they are most probably a consequence of allergic response to mesalazine.

Host-associated genetic differentiation in a seed parasitic weevil Rhinusa antirrhini (Coleptera: Curculionidae) revealed by mitochondrial and nuclear sequence data.

Plant feeding insects and the plants they feed upon represent an ecological association that is thought to be a key factor for the diversification of many plant feeding insects, through differential adaptation to different plant selective pressures. While a number of studies have investigated diversification of plant feeding insects above the species level, relatively less attention has been given to patterns of diversification within species, particularly those that also require plants for oviposition and subsequent larval development. In the case of plant feeding insects that also require plant tissues for the completion of their reproductive cycle through larval development, the divergent selective pressure not only acts on adults, but on the full life history of the insect. Here we focus attention on Rhinusa antirrhini (Curculionidae), a species of weevil broadly distributed across Europe that both feeds on, and oviposits and develops within, species of the plant genus Linaria (Plantaginaceae). Using a combination of mtDNA (COII) and nuclear DNA (EF1-alpha) sequencing and copulation experiments we assess evidence for host associated genetic differentiation within R. antirrhini. We find substantial genetic variation within this species that is best explained by ecological specialisation on different host plant taxa. This genetic differentiation is most pronounced in the mtDNA marker, with patterns of genetic variation at the nuclear marker suggesting incomplete lineage sorting and/or gene flow between different host plant forms of R. antirrhini, whose origin is estimated to date to the mid-Pliocene (3.77 Mya; 2.91-4.80 Mya).

Phytophthora ramorum Occurrence in Ornamentals in Serbia.

In a survey to determine the presence of Phytophthora ramorum in Serbia, ornamentals from garden centers, nurseries, and private and public gardens, as well as imported plant material, were inspected. In total, 577 plant, soil, and potting media samples were tested using various detection methods: lateral flow diagnostic test, enzyme-linked immunosorbent assay, conventional polymerase chain reaction, and isolation, followed by identification based on growth characteristics in culture and morphological features. P. ramorum was not detected in any of the 162 soil or potting media tested by the baiting method. P. ramorum was detected in 12 Rhododendron samples from one private garden in Zemun (City of Belgrade District) exhibiting symptoms of leaf necrosis and blight and petiole necrosis, and in three samples of Pieris spp. from one garden center exhibiting symptoms of leaf necrosis. Eight Phytophthora isolates were obtained from the positive Rhododendron plants and three isolates from Pieris plants, and all were identified as P. ramorum on the basis of their uniform morphological and growth characteristics. P. ramorum conformation was also made by sequencing of the internal transcribed spacer regions for a single isolate taken from one infected rhododendron and one pieris plant. Serbian isolates were determined as A1 mating type, due to formation of a few typical sexual structures when crossed with the A2 mating type of P. cinnamomi and P. cryptogea. Pathogenicity test on nonwounded detached leaves of 19 popular ornamentals, as well as the most frequently imported ones, revealed that 10 host species were susceptible, including Robinia pseudoacacia, which is widely distributed in Serbia. During this study, Cotoneaster horizontalis and C. dammeri were determined to be new experimental hosts of P. ramorum. This article provides evidence of P. ramorum introduction into Serbia. Although P. ramorum has not been detected in Serbian production nurseries, its presence outdoors might cause severe damages on susceptible common urban plants in public green and natural ecosystems.

Incidence and Distribution of Iris yellow spot virus on Onion in Serbia.

In a survey to determine the presence and distribution of Iris yellow spot virus (IYSV) in greenhouse ornamentals and onion field crops in 14 districts of Serbia as well as on imported ornamental plants, 1,574 samples were collected and analyzed by double-antibody sandwich enzyme-linked immunosorbent assay (DAS-ELISA). IYSV was not detected in nearly 1,200 plant samples collected from 39 genera of ornamentals grown in greenhouses in Serbia or imported from other countries during 2005 to 2007. The virus was detected in samples from an onion seed crop in the Sirig locality (South Backa District) that showed symptoms resembling those caused by IYSV and in samples without IYSV-like symptoms from an onion bulb crop in the Obrenovac locality (City of Belgrade District). Mechanical transmission of IYSV isolates was difficult, and only the isolate 605-SRB could infect four plant species, but not in all replications. No virus transmission could be demonstrated in 5,000 tested seeds originating from IYSV-infected onion crops. For further confirmation of IYSV, the nucleotide sequence of its nucleocapsid (NC) gene was obtained by reverse transcription-polymerase chain reaction (RT-PCR) in symptomatic onion samples as well as in symptomless leaves of Nicotiana benthamiana. Four previously developed primers were tested to determine their suitability for routine detection of Serbian IYSV isolates. Phylogenetic analysis showed clustering of isolates 605-SRB and 622-SRB from the onion seed crop and isolate 283-SRB from the onion bulb crop into two distant clades. The analysis indicated that Serbian isolates of IYSV do not share a recent common ancestor and that they represent two distinct lineages of IYSV in Serbia. Considering that onion is one of the most important and traditionally grown vegetable crops in Serbia, IYSV represents a potentially devastating pathogen in this country.