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Buprestids are an emerging threat to broadleaf forests across the world. Species such as emerald ash borer (EAB, Agrilus planipennis) seriously threaten ash (Fraxinus spp.) in North America and Europe. As it continues spreading west from European Russia, native European ash populations will suffer dramatic losses. Due to their cryptic lifestyle of the egg and larval stages on developing bark and vascular tissue, buprestids and other wood borers can be difficult to detect. Early detection tools are vital to implement fast eradication measures, and prevent the establishment of invasive species populations. Detection methods using polymerase chain reaction (PCR) assays to target specific taxa can be extremely timely to obtain results especially since samples need to be transported to the laboratory first. However, loop-mediated isothermal amplification (LAMP) eDNA assays are highly specific and sensitive providing results within 30 min after sample extraction. In this study, we investigated the specificity and sensitivity of an EAB LAMP assay as an early detection tool in Europe. The assay was specific to EAB when tested against 12 European Agrilus spp., five buprestids, two Scolytinae, and five cerambycids (n = 24). The LAMP assay sensitivity amplified DNA from a concentration as low as 0.02 pg/µL. These results demonstrate that the LAMP assay is a highly specific, sensitive tool that can be used to detect and monitor EAB in European forests and urban settings.

Riparian ecosystems, in long-time developed regions, are among the most heavily impacted by human activities; therefore, the distribution of tree riparian species, such as

Producción Científica, Fusarium circinatum, the causal agent of pine pitch canker (PPC), is currently one of the most important threats of Pinus spp. globally. This pathogen is known in many pine-growing regions, including natural and planted forests, and can affect all life stages of trees, from emerging seedlings to mature trees. Despite the importance of PPC, the global distribution of F. circinatum is poorly documented, and this problem is also true of the hosts within countries that are affected. The aim of this study was to review the global distribution of F. circinatum, with a particular focus on Europe. We considered (1) the current and historical pathogen records, both positive and negative, based on confirmed reports from Europe and globally; (2) the genetic diversity and population structure of the pathogen; (3) the current distribution of PPC in Europe, comparing published models of predicted disease distribution; and (4) host susceptibility by reviewing literature and generating a comprehensive list of known hosts for the fungus. These data were collated from 41 countries and used to compile a specially constructed geo-database. A review of 6297 observation records showed that F. circinatum and the symptoms it causes on conifers occurred in 14 countries, including four in Europe, and is absent in 28 countries. Field observations and experimental data from 138 host species revealed 106 susceptible host species including 85 Pinus species, 6 non-pine tree species and 15 grass and herb species. Our data confirm that susceptibility to F. circinatum varies between different host species, tree ages and environmental characteristics. Knowledge on the geographic distribution, host range and the relative susceptibility of different hosts is essential for disease management, mitigation and containment strategies. The findings reported in this review will support countries that are currently free of F. circinatum in implementing effective procedures and restrictions and prevent further spread of the pathogen., COST Action FP1406 (PINESTRENGTH), the Estonian Science Foundation grant PSG136, the Forestry Commission, United Kingdom, the Phytophthora Research Centre Reg. No. CZ.02.1.01/0.0/0.0/15_003/0000453, a project co-financed by the European Regional Development Fund., French National Research Agency (ANR) (ANR-11-LABX-0002-01), BBSRC, Defra, ESRC, the Forestry Commission, NERC and the Scottish Government (BB/L012251/1)

Invasive forest pathogens are a major threat to forests worldwide, causing increasing damage. The knowledge of both the specific traits underlying the capacity of a pathogen to become invasive, and the attributes predisposing an environment to invasion are to be thoroughly understood in order to deal with forest invasions. This paper summarizes the historical knowledge on this subject. Many aspects of the ecological processes underlying alien forest pathogens invasions are still unknown, which raises several scientific issues that need further study. The introduction of invasive forest pathogens to areas where naïve hosts are found, is mainly due to global plant trade. Rapid transportation and reduced delivery times increase the chances of survival of pathogen propagules and of their successful establishment in new environments. In forest pathogens, the reproduction mode seems not to be a crucial determinant of invasiveness, as highly destructive pathogens have a variety of reproductive strategies. The most important drivers of forest pathogen invasions appear to be (a) great adaptability to new environmental conditions; (b) efficient dispersal over long and short distances, possibly assisted by the capacity to form novel associations with endemic and/or alien insect vectors; (c) the ability to exchange genetic material or hybridize with resident or alien species. Moreover, these features interact with some key traits of the invaded environment, e.g. environmental variability and biodiversity richness. Host resistance and natural enemies may occur as a result of rapid selection/adaptation after the epidemic phase of invasion.

Ceratocystis platani causes canker stain of plane trees, and it represents a serious disease of Platanus spp. both in the United States and Europe. Current chemical or biological controls do not effectively manage C. platani, so new preventive methods need to be developed in order to limit this pathogen spreading. In this work, we have characterized the main volatile organic compounds (VOC) emitted in vitro from pure cultures of C. platani and other common pathogenic fungal species of hosts plants growing in the same ecosystems as plane trees. We found that C. platani emitted a similar blend of VOC compared with phylogenetically similar species C. populicola. In particular, C. platani was characterized by emission of isoamyl acetate and isobutyl acetate while C. populicola by ethyl acetate and isobutyl acetate, which were not released by any of the other out-group fungal species grown on the same medium. Moreover, following a targeted approach based on the main VOC found in vitro, we have successfully validated in vivo that VOC uniquely emitted by C. platani (i.e. isobutyl acetate along with isoamyl alcohol) were released from the bark of plane trees following C. platani inoculation. Our results highlight the possibility to exploit VOC emitted specifically by C. platani as biomarkers to recognize Platanus x acerifolia plants infected by this pathogen.

In response to the first Dutch elm disease (DED) pandemic, Siberian elm, Ulmus pumila, was planted to replace the native elm, U. minor, in Italy. The potential for hybridization between these two species is high and repeated hybridization could result in the genetic swamping of the native species and facilitate the evolution of invasiveness in the intro- duced species. We used genetic markers to examine the extent of hybridization between these two species and to determine the pattern of introgression. We quantified and compared the level of genetic diversity between the hybrids and the two parental species. Hybrids between U. pumila and U. minor were common. The pattern of introgression was not as strongly biased towards U. pumila as was previously observed for hybrids between U. rubra and U. pumila in the United States. The levels of heterozygosity were similar between U. minor and the hybrids and both groups had higher levels of heterozygosity relative to U. pumila. The programs Structure and NewHybrids indicated the presence of first- (F1) and second- generation (F2) hybrids and of backcrosses in the hybrid population. The presence of healthy DED resistant U. minor individuals combined with the self- compatibility of U. minor could help explain the presence of F2 individuals in Italy. The presence of F2 individuals, where most of the variability present in the hybrids will be released, could facilitate rapid evolution and the potential evolution of invasiveness of U. pumila in Italy.

Summary Dutch elm disease (DED) has spread through Europe and North America since the beginning of the twentieth century. In response, several independent genetic improvement programmes for breeding DED-resistant elms have been established on both sides of the Atlantic. Assimilating a wide range of resistant clones of different parentage should help ensure survival of the elm in the event of mutation of the pathogen. The Italian elm breeding programme began in the late 1970s and has recently raised a new variety by crossing a specimen of U. chenmoui with the Dutch hybrid clone ‘405’. This new release, named ‘Morfeo’, is extremely resistant to DED and has an attractive form and foliage. It is also fast-growing, tolerant of drought and soils waterlogged in winter, therefore proving well adapted to the climates of both north-western Europe and the Mediterranean. Following trials in England, ‘Morfeo’ is considered of potential importance in the conservation of several invertebrates endangered by the consequences of DED.

Conventionally hybrid elm clones obtained within breeding programs for Dutch elm disease (DED) resistance were selected to meet requirements for use as ornamentals. However, it has been long and commonly observed that these clones may show hybrid vigour and enhanced growth. Nowadays DED resistant hybrid elm clones, which have been released to the market or are under evaluation for an upcoming release, are numerous enough to be considered for timber production or short rotation coppice (SRC). But experimental testing of the growth performances of these clones in different environments is still lacking. In this paper, growth and stability of performance of 24 DED resistant hybrid elm clones planted at three experimental sites with contrasting environmental conditions in Italy were studied. Height and diameter were measured yearly from 2001 to 2009, and the mean yearly increments after plant establishment were calculated. The study revealed a general good growth performance of the majority of the clones with mean height increments above 1 m/year, and an excellent growth performance of some genotypes. Analysis of variance showed significant effects of clone, site and clone × site interaction, for both height and diameter increments. Stability analysis of diameter and height increments was performed by using two parametric (CV% and W2) and two non-parametric (Huhn's Si(1) and Si(2)) indexes. According to all indexes, two clones showed superior and stable growth. These clones may be suitable for planting in a range of environments. In addition, several other clones had high growth in general or at a particular site. The results support our belief that these elm clones could be successfully used for timber and biomass production, and provide new knowledge for an informed choice of the most suitable genotypes.

Summary Ceratocystis platani was detected at several locations in the European side of Istanbul, causing severe dieback and mortality, mainly on Platanus × acerifolia imported from Italy approximately 160 years ago, but also on Platanus orientalis. In the work reported here, the causal agent of the dieback and mortality was identified based on morphological characteristics in culture and internal transcribed spacer (ITS) sequencing, confirming the presence of C. platani in Turkey. All analysed C. platani isolates from Istanbul shared the same ITS sequence with European C. platani strains available in the NCBI, but differed from other species previously ascribed to the Ceratocystis fimbriata species complex. Pathogenicity of C. platani was proven by inoculation onto 25-cm-long and 4–9 mm diam. P. orientalis twigs and the causal agent reisolated from symptomatic tissues. In a survey of 976 Platanus in streets and parks of Istanbul, 26.5% of trees showed symptoms of C. platani infections, whilst 5.6% were dead. The proportion of symptomatic trees was higher where management interventions, such as topping or pruning and felling infected trees had been carried out.

We studied the influence of hypertensive (HT) serum on human umbilical vein endothelial cell (HUVEC) and on human umbilical artery smooth muscle cell (HUASMC) proliferation. We also tested the possible influence of the HT serum on vasoconstrictor substances released by HUVECs.Pools of HT and normotensive (NT) sera were collected and used to supplement cell culture medium. Both HUVECs and HUASMCs were conditioned with culture media supplemented with either HT or NT sera. After conditioning, both types of cells were tested for proliferative capacity. Under the same experimental conditions the HUVEC conditioned medium was assayed for angiotensin II (AII) and endothelin 1 (ET,). All and ET, were also assayed after acute exposure to HT serum of HUVEC preconditioned with NT serum.Our results showed that HUVEC and HUASMC conditioned with HT serum substantially enhanced cell proliferation. Preconfluent HUVECs conditioned with HT serum showed higher levels of AZZ and lower levels of ET1 compared with the controls ...

We examined the effect of ambient ozone on visible foliar injury, growth and biomass in field-grown poplar cuttings of an Oxford clone sensitive to ozone (Populus maximoviczii Henry x berolinensis Dippel) irrigated with ethylenediurea (EDU) or water for three years. EDU is used as an ozone protectant for plants. Protective effects of EDU on ozone visible injury were found. As a result, poplar trees grown under EDU treatment increased leaves, lateral branches and root density in the third year, although no significant enhancement of stem height and diameter was found. Ambient ozone (AOT40, 24.6 ppm h; diurnal hourly average, 40.3 ppb) may finally reduce carbon gain by reducing the number of branches, and thus sites for leaf formation, in ozone-sensitive poplar trees under not-limiting conditions.

Since the onset of the 20th century, two pandemics of Dutch elm disease (DED) destroyed native elms throughout Europe and North America. The disease is caused by two invasive fungi, Ophiostoma ulmi (Buisman) Nannf. and Ophiostoma novo-ulmi Brasier, which appeared one after another and were new to science. From the late 1920s, in Europe and in the US, researchers strove to find natural resistance to DED in native elms, but their efforts yielded ephemeral success. The resistant cultivars obtained in the 1930s by hybridizing European elm genotypes, were defeated by the second pandemic. The inclusion of Asian resistant species in breeding programs finally produced resistant second-generation hybrids. In Italy a program to breed resistant clones for the Mediterranean climate, was started in the mid 1970s. The successful use of Asian species in the country encouraged an in-depth assessment of their adaptability to local climates for broadening the genetic base of breeding. Selection of superior genotypes reduces genetic variation. However, when breeding is designed to obtain multiple genotypes for diverse conditions and uses, variation can be maintained. The case of elm is paradigmatic. Since elms have many uses, and an important one is as ornamentals, breeding included the selection of genotypes with fast growth, and attractive crown shape and foliage. To meet all needs and provide genetically variable cultivars to deal with climate change and new diseases, genetic resources were broadened. Native elms with good aesthetic qualities were crossed with DED-resistant and adaptable Asian genotypes. The program produced resistant clones adapted to summer drought and winter floods, yet endowed with notable ornamental features. Five of these clones were patented. A similar strategy including both the crossing of European Fraxinus species and of native with non-native resistant genotypes, may be successful against Hymenoscyphus fraxineus, the invasive agent of the European ash dieback epidemic.