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At least 19 recordsLinked to original sources
PubMed2001

Final report on the safety assessment of Corylus Avellana (Hazel) Seed Oil, Corylus Americana (Hazel) Seed Oil, Corylus Avellana (Hazel) Seed Extract, Corylus Americana (Hazel) Seed Extract, Corylus Avellana (Hazel) Leaf Extract, Corylus Americana (Hazel) Leaf Extract, and Corylus Rostrata (Hazel) Leaf Extract.

These ingredients are all derived from hazelnut trees. The two seed oils are expressed from the nuts of the hazelnut tree of the particular species identified. Most current reported cosmetic uses are of the seed oils. The seed extracts are the extract of the nuts of the identified species tree. There is one current report of use of seed extract in cosmetics. The leaf extracts are the extract from the leaves of the particular species tree. There are no current reports of use of these extracts in cosmetics. Analysis of seed oil from one species identified Oleic Acid, Palmitoleic Acid, Linoleic Acid, Eicosaenoic Acid, Docosenoic Acid, Eicosanoic Acid, Palmitic Acid, Linolenic Acid, Stearic Acid, and Tetraeicosanoic Acid. Little information is available to characterize the extracts, however. The functions of most of these ingredients in cosmetics are not reported. In studies of hazelnuts from Spain and Egypt, aflatoxin was reported as a possible contaminant. Aflatoxins are considered carcinogenic in humans. Virtually no safety test data are available on these ingredients. Negative results in one comedogenicity study using a seed oil are reported. Cross-sensitivity to proteins in peanuts and those in hazelnuts are reported, but the presence or absence of protein in nut extract and plant extract from hazelnut trees is not known. Additional data were provided regarding concentration of use, method of extraction and contaminants, comedogenicity, and ultraviolet (UV) radiation absorption, but these data related to nut oil from only one species, and were not overall sufficient to resolve questions about irritation, sensitization, and photosensitization. Because of the absence of data, it is concluded that the available data are insufficient to support the safety of these ingredients in cosmetic products. Because of the limited information that characterizes any of these oils or extracts, data are needed on each (except that items 1, 2, and 3 below are not needed for Hazel [Corylus Avellana] Nut Oil). The additonal data needs include: (1) current concentration of use; (2) method of extraction/manufacture and quality control (i.e., chemical analyses); (3) contaminants and methods of extraction (especially pesticides and heavy metals); (4) dermal irritation and sensitization; (5) UV absorption; if there is significant absorption, then a photosensitization study will be needed; (6) 28-day dermal toxicity; (7) reproductive and developmental toxicity; and (8) two genotoxicity assays, one in a mammalian system; if positive, then a 2-year dermal carcinogenesis study using National Toxicology Program (NTP) methods may be needed.

Acne Vulgaris↗
PubMed2001

Comparative analysis of pollen counts of Corylus, Alnus and Betula in Szczecin, Warsaw and Lublin (2000-2001).

The aim of the study was to compare the airborne concentrations of allergenic pollen produced by three early flowering tree taxa (Corylus, Alnus, Betula) in the cities of Warsaw (central Poland), Lublin (eastern Poland) and Szczecin (western Poland) during the years 2000-2001. Measurements were performed by the volumetric method. Pollen seasons were defined as the periods in which 95% of the total catch occurred. The highest concentration and annual pollen count of Corylus was measured in Lublin in both seasons, while the highest annual pollen counts of Alnus and Betula were noted in Warsaw, where the annual pollen count of Betula in 2001 was four times higher than in 2000 and equalled 5,376 grains in m3 per 24 h. Significant differences in the pollen count of the examined taxa were observed between two seasons: the pollen count of Corylus was higher in 2000 than in 2001, while for Alnus and Betula the opposite was the case. The longest pollen seasons were observed at low annual pollen counts for the pollen of Corylus. Results of the study reveal significant differences between the seasons and the cities. The differences concern the dates of the appearance of pollen grains in the air, the duration of the presence of sporomorphs and the maximum concentrations in particular seasons. The pollen counts of alder, birch and hazel trees are determined by the weather, diversity of local flora and specific rhythm of pollination of particular taxa.

Air Pollution↗
PubMed2002

Chloroplast DNA variation, postglacial recolonization and hybridization in hazel, Corylus avellana.

To unravel the postglacial migration history of hazel, Corylus avellana, the genetic variation at two types of chloroplast DNA markers, polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) and microsatellites, was assessed in 26 natural hazel populations distributed across the range of C. avellana. In addition a sequence of 2468 base pairs, which contains the matK gene, was analysed in seven individuals. Very little variation was detected overall [hT:PCR-RFLP= 0.091, hT:microsatellite= 0.423, pi (nucleotide diversity) = 0.00093] but the microsatellite markers, which have the highest levels of variation, show a clear geographical structure that divides Europe into two areas: (i) Italy and the Balkans, on one hand and (ii) the rest of Europe, on the other hand. These data exclude Italy and the Balkans as possible origins of the postglacial recolonization but cannot unambiguously show which other area is the origin, since the genetic data does not indicate the direction of spread. If we take the pollen record into account, the most likely scenario would be an expansion from southwestern France into most of Europe except Italy and the Balkans, and then a local expansion in the latter area. The two main haplotypes identified with both PCR-RFLP and sequencing, A and B, were found not only in C. avellana but also in other European Corylus species and cultivars. Haplotype A, which is dominating all investigated natural populations of C. avellana, is also found in the European tree hazel (C. colurna) and haplotype B, which is rare in C. avellana, has been identified in the filbert (C. maxima) and C. avellana cultivars. This pattern seems to indicate a history of past hybridization among the European Corylus species and cultivars.

Corylus↗
PubMed2004

Comparison of Alnus, Corylus and Betula pollen counts in Lublin (Poland) and Skien (Norway).

Symptoms of pollen allergy in springtime in Middle and Northern Europe are mainly caused by pollen grains of birch, hazel and alder. The aim of the present study was the pollen fall comparison of the mentioned taxa in Lublin (Poland) and Skien (Norway). These sites are located approximately 1,200 km away apart by air. The pollen monitoring was carried out by gravimetric method in 1999-2000. The start and end of pollen seasons were defined by the 90% method. The beginning of pollen seasons for Corylus and Betula were observed 1-3 weeks earlier in Lublin than in Skien, but pollen grains of Alnus appeared simultaneously in both towns. In 1999, annual totals of Alnus, Corylus and Betula pollen grains were considerably less numerous in Skien than in Lublin. No important differences were observed among the pollen fall amounts of the mentioned taxa in 2000. The maximum values of pollen grains were defined in different terms. The results of investigations differed as regards the years compared as well as the sites.

Alnus↗
PubMed1999

Effects of Corylus avellana in acetaminophen and CCl4 induced toxicosis.

Our study investigated the effects of Corylus avellana extract on acetaminophen and carbon tetrachloride intoxicated liver of young rats. Hepatocytolysis was determined by measuring the level of serum transaminases (GPT and GOT), steatosis by Sudan black staining, histological structures by hamatoxylineosin staining and the activity of enzymes such as SDH, GtDH, G-6-Pase and ATPase. Comparatively, the most serious lesions appeared in CCl4 intoxication. Corylus avellana extract had some beneficial effects in CCl4 toxicosis: it reduced hepatocytolysis as well as histological lesions and returned the activity of some enzymes to normal values.

Acetaminophen↗
PubMed1993

Variations in leaf morphometry and nitrogen concentration in Betula pendula Roth., Corylus avellana L. and Lonicera xylosteum L.

Relations between leaf dry weight to leaf area (LWA), leaf nitrogen concentration and irradiance inside a natural canopy were studied in Betula pendula Roth., Corylus avellana L. and Lonicera xylosteum L. In all species, LWA increased with increasing irradiance. Relative variability in LWA was smaller in Betula pendula than in the other two species. In Corylus avellana, LWA also depended on total plant height. Foliar nitrogen concentration (on a dry weight basis) increased with increasing irradiance and LWA in Betula pendula, but decreased in the other two species. The interspecific variation in response to light availability and in nitrogen partitioning may be caused by different light demands or different life forms (trees versus shrubs), or both, of the species examined, and must be considered in contemporary canopy models.

Journal Article↗
PubMed2003

RAPD markers linked to eastern filbert blight resistance in Corylus avellana.

A total of 1,110 decamer primers were screened for RAPD markers linked to a dominant allele in hazelnut ( Corylus avellana) that confers resistance to eastern filbert blight caused by Anisogramma anomala. Twenty RAPD markers linked in coupling, and five markers linked in repulsion, were found. A seedling population was used to construct a linkage map of the region flanking the resistance locus. The map spans 46.6 cM, with 14 markers on one side of the resistance locus and eight on the other side. Eleven markers showed less than 3% recombination with resistance, including three that showed no recombination. Seven of these 11 markers are sufficiently robust to allow their use in marker-assisted selection. These include AA12(850) which shows no recombination, and six markers on one side of the resistance locus: 173(500), 152(800), 122(825), 275(1130), H19(650) and O16(1250). Marker 268(580), which flanks the resistance locus on the other side, is also suitable for use in marker-assisted selection, but shows 5.8% recombination with resistance. Other markers are less suitable for marker-assisted selection because of sensitivity to changes in primer or MgCl(2) concentration, or the long time required for electrophoresis to separate bands of similar size. The 16 markers closest to the resistance locus were cloned and sequenced. The W07(365) marker, which showed no recombination with the resistance locus but is difficult to score, includes a CT microsatellite repeat. The sequence information will allow the design of SCAR primers and eventual map-based cloning of the resistance allele.

Base Sequence↗
PubMed2004

Isolation and partial characterisation of acid phosphatase isozymes from dormant oilseed of Corylus avellana L.

The acid phosphatase (orthophosphoric-monoester phosphohydrolase, EC 3.1.3.2) complement from dormant hazel (Corylus avellana L.) seeds was found to exhibit significant electrophoretic heterogeneity partially attributable to the presence of distinct molecular forms. In axiferous tissue, total acid phosphatase activity increased in a biphasic fashion during chilling, a treatment necessary to alleviate seed dormancy. Three acid phosphatase isozymes were isolated from cotyledons of dormant hazel seeds by successive ammonium sulphate precipitation, size-exclusion, Concanavalin A affinity, cation- and anion-exchange chromatographies resulting in 75-, 389- and 191-fold purification (APase1, APase2, APase3, respectively). The three glycosylated isoforms were isolated to catalytic homogeneity as determined by electrophoretic, kinetic and heat-inactivation studies. The native acid phosphatase complement of hazel seeds had an apparent Mr of 81.5 +/- 3.5 kDa as estimated by size-exclusion chromatography, while the determined pI values were 5.1 (APase1), 6.9 (APase2) and 7.3 (APase3). The optimum pH for p-nitrophenyl phosphate hydrolysis was pH 3 (APase1), pH 5.6 (APase2) and pH 6 (APase3). The hazel isozymes hydrolysed a variety of phosphorylated substrates in a non-specific manner, exhibiting low Km and the highest specificity constant (Vmax/ Km) for pyrophosphate. They were not primary phytases since they could not initiate phytic acid hydrolysis, while APase2 and APase3 had significant phospho-tyrosine phosphatase activity. Inorganic phosphate was a competitive inhibitor, while activity was significantly impaired in the presence of vanadate and fluoride.

Acid Phosphatase↗
PubMed2003

Isolation and characterisation of phytase from dormant Corylus avellana seeds.

Phytase (myo-inositol-1,2,3,4,5,6-hexakisphosphate phosphohydrolase, EC 3.1.3.26), which catalyses the step-wise hydrolysis of phytic acid, was purified from cotyledons of dormant Corylus avellana L. seeds. The enzyme was separated from the major soluble acid phosphatase by successive (NH4)(2)SO(4) precipitation, gel filtration and cation exchange chromatography resulting in a 300-fold purification and yield of 7.5%. The native enzyme positively interacted with Concanavalin A suggesting that it is putatively glycosylated. After size exclusion chromatography and SDS-PAGE it was found to be a monomeric protein with molecular mass 72+/-2.5 kDa. The hazel enzyme exhibited optimum activity for phytic acid hydrolysis at pH 5 and, like other phytases, had broad substrate specificity. It exhibited the lowest Km (162 microM) and highest specificity constant (V(max)/Km) for phytic acid, indicating that this is the preferred in vivo substrate. It required no metal ion as a co-factor, while inorganic phosphate and fluoride competitively inhibited enzymic activity (Ki=407 microM and Ki=205 microM, respectively).

6-Phytase↗
PubMed2004

Hazelnut (Corylus avellana) vicilin Cor a 11: molecular characterization of a glycoprotein and its allergenic activity.

In Europe, hazelnuts (Corylus avellana) are a frequent cause of food allergies. Several important hazelnut allergens have been previously identified and characterized. Specific N-glycans are known to induce strong IgE responses of uncertain clinical relevance, but so far the allergenic potential of glycoproteins from hazelnut has not been investigated. The aim of the study was the molecular characterization of the glycosylated vicilin Cor a 11 from hazelnut and the analysis of its allergenic activity. Although MALDI-TOF (matrix-assisted laser-desorption ionization-time-of-flight) MS showed that one of two potential glycosylation sites of Cor a 11 was glycosylated, CD spectroscopy indicated that recombinant and natural Cor a 11 share similar secondary structures. Thus to analyse the impact of the glycan residues of Cor a 11 on IgE binding, the allergenic activity of natural glycosylated Cor a 11 and recombinant Cor a 11 was compared. In addition, the IgE sensitization pattern to recombinant Cor a 11, Cor a 1, Cor a 2 and Cor a 8 of 65 hazelnut allergic patients was determined in vitro. The prevalence of IgE reactivity to hazelnut vicilin Cor a 11 was below 50%. Basophil histamine-release assays were used to determine the allergenic activity of both natural and recombinant Cor a 11 in comparison with Cor a 1, a birch (Betula verrucosa) pollen-related major hazelnut allergen. Both forms of Cor a 11 induced mediator release from basophils to a similar extent, indicating that the hazelnut allergic patients had cross-linking IgE antibodies binding to the protein backbone and not to carbohydrate structures. In comparison to Cor a 1, a 10000-fold higher concentration of Cor a 11 was required to induce similar basophil mediator release. In conclusion, the hazelnut vicilin Cor a 11 is a minor allergen both in regard to prevalence and allergenic potency, whereas its glycan does not contribute to its allergenic activity.

Allergens↗
PubMed2004

Phytic acid mobilization is an early response to chilling of the embryonic axes from dormant oilseed of hazel (Corylus avellana).

Dormancy of hazel (Corylus avellana L.) seeds is alleviated by a chilling treatment during which cytological, hormonal, and biochemical changes occur. Phytic acid and phosphate mobilization have been examined during this treatment. Phytic acid accounted for 0.7% and up to 3.2% of dry weight in axiferous and cotyledonary tissue, respectively. Phytic acid levels in embryonic axes were reduced by 60% within the first 3 weeks of chilling, with little subsequent change, in contrast to warm-imbibed tissue where levels did not change significantly. In cotyledons, phytic acid was mobilized to a lesser extent. Phosphate levels expressed on a fresh weight basis remained almost unaltered suggesting either the operation of a homeostatic mechanism for intracellular concentration or rapid utilization due to active metabolism. Phytase activity increased during stratification in both axiferous and cotyledonary tissue. The initial rise observed was associated with dormancy alleviation, since it occurred before the realization of full germination potential by the seeds and not in warm-imbibed tissue. Protein bodies were isolated from hazel seeds by non-aqueous density gradients. Phytase activity was closely associated with the purified organelles, where phytic acid was located by light microscopy. Overall, these findings suggest that phytic acid mobilization by phytase and previously described processes associated with protein bodies, such as considerable proteolysis, are early participants in the plethora of events leading to seed dormancy relief and germination in hazel.

6-Phytase↗
PubMed2003

Hyper-expression of small nucleolar RNAs (snoRNAs) in female inflorescences of hazelnut (Corylus avellana L.) supports rRNA aggregation in vitro.

Under certain in vitro (salt and temperature) conditions rRNA aggregation occurs in female inflorescences but not in leaves or pollen RNA preparations from hazelnut (Corylus avellana L.), a species of economic interest. This paper describes experiments addressing an explanation of this phenomenon. The experiments demonstrate that: (i) trans-acting factors induce rRNA aggregate formation in female inflorescences RNA preparations; (ii) these factors support aggregation also of heterologous rRNA; (iii) aggregation is a function of temperature pre-treatment of rRNA and not of source 18S rRNA; (iv) the factors inducing rRNA aggregates are sensitive to RNase; (v) antisense small nucleolar RNAs (snoRNAs) participate in rRNA aggregate formation. snoRNAs are involved in pre-rRNA spacer cleavages, and are required for the two most common types of rRNA modifications: 2'-O-ribose methylation and pseudouridylation. Even though it is questionable whether rRNA aggregation really happens in female inflorescence in vivo, the phenomenon observed in vitro may reflect the abundance of snoRNAs in these reproductive structures. In fact the level of accumulation of three tested snoRNAs, R1, U14 and U3, is much higher in female inflorescence than in leaves or pollen of hazelnut. This finding opens the possibility of studying the role of snoRNAs in tissue development in plants.

Base Sequence↗
PubMed1994

Kinesin-related polypeptide is associated with vesicles from Corylus avellana pollen.

A 100-kDa polypeptide with microtubule-interacting properties was identified in a Golgi vesicle-enriched fraction from Corylus avellana pollen. The k71s23 antibody (directed to the kinesin heavy chain from bovine brain) [Tiezzi et al., 1992: Cell Motil. Cytoskeleton 21:132-137] localized the polypeptide on the external surface of membrane-bounded organelles. Some 100-kDa-containing vesicles copelleted with microtubules (polymerized from purified bovine brain tubulin) either in presence or absence of 5 mM AMPPNP, but they could be released by 10 mM ATP or 0.5 M KCl. The pollen microtubule-interacting protein, salt-extracted from membranes and partially purified by gel filtration, exhibited an ATPase activity (16.2 nmolPi/mg/min) which could be stimulated about 2-fold (32.5 nmolPi/mg/min) by addition of bovine brain microtubules. We suppose that the 100-kDa polypeptide is part of a molecular complex showing properties of the kinesin class.

Animals↗
PubMed2001

Effects of leaf wetting and high humidity on stomatal function in leafy cuttings and intact plants of Corylus maxima.

When rooted cuttings of Corylus maxima Mill. cv. Purpurea are moved from the wet and humid conditions of the rooting environment, the leaves frequently shrivel and die. Since the newly formed adventitious root system has been shown to be functional in supplying water to the shoot, stomatal behaviour in C. maxima was investigated in relation to the failure to prevent desiccation. Stomatal conductance (gs) in expanding leaves (L3) of cuttings increased almost 10-fold over the first 14 days in the rooting environment (fog), from 70 to 650 mmol m-2 s-1. In contrast, gs of expanded leaves (L1) changed little and was in the region of 300 mmol m-2 s-1. Midday leaf water potential was much higher in cuttings than in leaves on the mother stock-plant (-0.5 versus -1.2 MPa) even before any roots were visible. Despite this, leaf expansion of L3 was inhibited by >50% in cuttings and stomata showed a gradual reduction in their ability to close in response to abscisic acid (ABA). To determine whether the loss of stomatal function in cuttings was due to severance or to unnaturally low vapour pressure deficit and wetting in fog, intact plants were placed alongside cuttings in the rooting environment. The intact plants displayed reductions in leaf expansion and in the ability of stomata to close in response to dark, desiccation and ABA. However, in cuttings, the additional effect of severance resulted in smaller leaves than in intact plants and more severe reduction in stomatal closure, which was associated with a 2.5-fold increase in stomatal density and distinctively rounded stomatal pores. The similarities between stomatal dysfunction in C. maxima and that observed in many species propagated in vitro are discussed, as is the possible mechanism of dysfunction.

Journal Article↗
PubMed1976

Orderly arrangement of ribosomes in the embryogenic callus tissue of Corylus avellana L.

Cultured callus tissue of hazel (Corylus avellana L.), which has the potency of somatic embryogenesis, was used for the study of cell ultrastructure in the course of callus growth and embryoid formation. The meristematic cells of this tissue exhibit a specific organization of rough endoplasmic reticulum (RER), stacked into extensive parallel sheets. The membranes of the aggregated RER are associated with orderly arrays of bound ribosomes. The high regularity of the alignment of the attached ribosomes seems to be influenced by the distance between the two neighbouring membranes in the RER aggregate. The RER aggregates with orderly attached ribosomes are more frequently found in callus cells and in early embryogenesis than in the advanced stages of embryo development.

Endoplasmic Reticulum↗
PubMed2001

Decline in stomatal response to leaf water deficit in Corylus maxima cuttings.

Many woody species can be propagated from leafy cuttings. However, following rooting, cuttings of Corylus maxima Mill. cv. Purpurea do not always survive the transition from a highly supportive rooting environment (e.g., fog) to a more natural environment where evaporative demand is higher. We found that it is not the supply of water to leaves, but stomatal dysfunction that leads to severe water deficits in the rooted cuttings. Two hours after well-rooted cuttings were transferred from the rooting environment, we were able to relate visible signs of leaf water deficit to high stomatal conductance (g(s)) and low relative water content (R). Small expanding leaves (L3) had unusually high g(s) and lower R than fully expanded leaves (L1). Although high cuticular conductances (g(c)) were occasionally observed in L3, SEM confirmed that increased total leaf conductance (g) was mainly a result of abnormally wide stomatal opening. We measured changes in the ability of stomata to control water loss during rooting by determining stomatal responsiveness to leaf water deficit in detached L1 and L3 harvested from cuttings during the first 75 days after severance from stock plants. Reduced stomatal responsiveness was observed within 7 days of severance, prior to adventitious root formation, and was more pronounced in L3 than in L1. A period of acclimatization after rooting (no leaf wetting, but a vapor pressure deficit of 0.20 kPa) reduced g(s) by 50% in L3 but not in L1, and partially restored stomatal responsiveness in L1 but not in L3. After rooting, the original leaves on the cutting retained substantial capacity for photosynthesis (e.g., in L1, 8 micromol m(-2) s(-1) at a photosynthetic photon flux density of 400 micromol m(-2) s(-1)). The implications of the results for post-rooting acclimatization procedures are discussed.

Betulaceae↗
PubMed1985

Immunochemical characterization of reference alder (Alnus glutinosa) and hazel (Corylus avellana) pollen extracts and the partial immunochemical identity between the major allergens of alder, birch and hazel pollens.

Dialysed extracts of alder (Alnus glutinosa) and hazel (Corylus avellana) pollens were characterized by immunochemical methods. The alder pollen extract contained at least 33 distinct antigens of which one, antigen 5, was classified as a major allergen, three, antigens 4, 10, and 17, were classified as intermediate allergens and two, antigens 19 and 23, were classified as minor allergens. The molecular weight and pI of the major allergen were determined to be 19,000 D and 5.2, respectively. The hazel pollen extract contained at least 40 distinct antigens, two of which were classified as major allergens, antigens 8 and 13, three as intermediate allergens, antigens 12, 17, and 26, and seven as minor allergens, antigens 6, 11, 16, 18, 29, 39, and 40. The molecular weights and pI's of the major allergens of hazel pollen were determined to be: antigen 8; Mw = 12,000 D, pI = 5.1 and less than 3.5, antigen 13; Mw = 26,000 D, pI = 5.1. Further, crossed line immunoelectrophoresis and tandem crossed immunoelectrophoresis of alder, birch and hazel strongly indicate that there exists an immunochemical partial identity between the major allergens (antigens 5 (alder), 23 (birch), and 13 (hazel)) from these tree pollens.

Allergens↗
PubMed2002

Bacteria associated with hazelnut (Corylus avellana L.) decline are of two groups: Pseudomonas avellanae and strains resembling P. syringae pv. syringae.

A total of 118 fluorescent pseudomonads associated with hazelnut decline, which has been occurring for many years in different areas of northern Greece and Italy, were assessed by performing a repetitive PCR analysis with enterobacterial repetitive intergenic consensus, box element, and repetive extragenic palindromic primer sets, sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) of whole-cell protein extracts, a carbon compound utilization analysis, and an analysis to determine the presence of the syrB gene. A subset of 53 strains was also characterized by amplified 16S ribosomal DNA restriction analysis (ARDRA) by using nine restriction endonucleases. The virulence of 40 representative strains was assessed by using serial doses. The pathogenic specificities of the strains were also verified. ARDRA carried out with HinfI revealed two main groups of strains, groups A and B, which exhibited a level of similarity of 57%. The other eight restriction endonucleases used did not separate the strains. In addition, a cluster analysis performed by the unweighted pair group method using arithmetic averages after repetitive PCR and SDS-PAGE of protein extracts also revealed the same two groups. Furthermore, the differential utilization of some carbon compounds made it possible to differentiate the groups. Virulence assessment clearly indicated that the group A strains are very virulent, whereas the group B strains proved to be mildly virulent for hazelnut. Group A included the strains isolated in northern Greece and central Italy (i.e., the province of Viterbo); these strains do not have the syrB gene, are pathogenically restricted to Corylus avellana, and belong to Pseudomonas avellanae. Group B includes the other strains obtained from hazelnut cultivated in Piedmont, Campania, Latium, Sicily, and Sardinia. They represent a distinct taxon closely related to Pseudomonas syringae pv. syringae.

Bacterial Proteins↗