Kai Metge

Bio: Kai Metge is an academic researcher from Julius Kühn-Institut. The author has contributed to research in topics: Xylophilus & Bursaphelenchus. The author has an hindex of 9, co-authored 14 publications receiving 858 citations.

First report of Bursaphelenchus xylophilus in Portugal and in Europe

Abstract: A survey of aphelenchid nematodes (Nematoda: Aphelenchida) associated with maritime pine, Pinus pinaster, was conducted in Portugal in 1996 and 1999. A Bursaphelenchus species has been identified for the first time in the Iberian Peninsula. B. xylophilus is reported for the first time in Europe. It was found in very high numbers - up to 38 000 per 10 g of pine wood - inside a few declining trees infested with curculionid, cerambycid and scolytid beetles. Morphological observations, including shape of spicules, bursa, vulva, female tail end and stylet as well as morphometrics, were in accordance with the species description. Species-specific DNA fragment patterns were obtained using ITS-RFLP analysis, with five different restriction enzymes. The importance and implications of this finding are discussed. Premiere signalisation de Bursaphelenchus xylophilus au Portugal, at en Europe - Une enquete sur les nematodes Aphelenchides (Nematoda: Aphelenchida) associes au pin maritime (Pinus pinaster) a ete realisee au Portugal de 1996 a 1999. Une espece de Bursaphelenchus a ete identifiee pour la premiere fois dans la Peninsule Iberique. B. xylophilus est signale pour la premiere fois en Europe. Il a ete trouve en tres grand nombre - jusqu'a 38 000 individus pour 10 g de bois de pin - dans des arbres deperissants infestes par des Coleopteres Curculionides, Cerambycides et Scolytides. Les observations concernant la morphologie - en particulier la forme des spicules, la bourse, la vulve, l'extremite de la queue de la femelle et le stylet - de meme que les donnees morphometriques correspondent a la description de l'espece. Des sequences de fragments d'ADN specifique de l'espece ont ete obtenus par analyse ITS-RFLP a l'aide de cinq enzymes de restriction. L'importance et les implications de cette decouverte sont discutees.

ITS-RFLP patterns for differentiation of 26 Bursaphelenchus species (Nematoda: Parasitaphelenchidae) and observations on their distribution

Abstract: RFLP analysis of the internal transcribed spacer (ITS) regions of ribosomal DNA has become a valuable tool for differentiation of Bursaphelenchus species. Restriction cleavage of amplified rDNA using five restriction enzymes (RsaI, HaeIII, MspI, HinfI and AluI) has provided species-specific ITS-RFLP patterns for 26 species of Bursaphelenchus and two intraspecific types so far, five of which are presented here for the first time. The technique has proved very valuable for differentiation of the pinewood nematode, B. xylophilus, from other Bursaphelenchus species during plant quarantine inspections. ITS-RFLP analysis has also been used effectively during investigations on the distribution of Bursaphelenchus species. ITS-RFLP patterns have been employed as additional identification criteria in the description of several new Bursaphelenchus species.

ITS-RFLP analysis, an efficient tool for differentiation of Bursaphelenchus species

Abstract: Restriction analysis of amplified ribosomal ITS sequences has provided species-specific fragment patterns for nematodes of several genera, including Bursaphelenchus. We used restriction enzymes RsaI, HaeIII, MspI, HinfI and AluI to produce ITS-RFLP reference profiles of 44 Bursaphelenchus species, including two intraspecific types in each of B. mucronatus and B. leoni. In addition, reference profiles of Aphelenchoides stammeri and Ruehmaphelenchus asiaticus were produced. Reference profiles of six species are shown here for the first time. Identical ITS-RFLP patterns were usually obtained from different isolates and from individual specimens of the same species. However, in the case of B. 'corneolus', B. lini, B. singaporensis and B. sexdentati, additional bands in the patterns of certain isolates or individual nematodes were observed which may be explained by ITS sequence microheterogeneity, i.e., the presence of ITS sequence variants within the number of rDNA tandem repeats. Since these 'extra' bands appeared only with one out of the five restriction enzymes employed, they did not seriously impair identification of species based on the overall reference patterns. ITS-RFLP analysis has proved valuable for differentiation of the pathogenic pine wood nematode, B. xylophilus, from related species. In many recent descriptions of new Bursaphelenchus species, ITS-RFLP profiles have been used as additional species identification criteria. Comparison of profiles from isolates of many different origins has provided new information on intraspecific types or genetically distinct provenances of several Bursaphelenchus species.

Lack of Genetic Variation of Bursaphelenchus xylophilus in Portugal Revealed by RAPD-PCR Analyses.

Abstract: Random Amplified Polymorphic DNA (RAPD-PCR) technique was used to assess the level of genetic variability and genetic relationships among 24 Portuguese isolates of pinewood nematode, Bursaphelenchus xylophilus. The isolates represent the main infested areas of Portugal. Two additional isolates of B. xylophilus representing North America and East Asia were included, and B. mucronatus was used as out-group. Twenty-eight random primers generated a total of 640 DNA fragments. The Nei and Li similarity index revealed a high genetic similarity among the Portuguese isolates (above 90%). Hierarchical cluster analysis was performed to illustrate the relatedness among the isolates. No indication for separate groups among the Portuguese isolates was obtained, and the low level of genetic diversity strongly suggests that they were dispersed recently from a single introduction. The lack of apparent relationship between the genetic and the geographic matrices of the Portuguese isolates limits the use of this technique for following recent pathways of distribution. Genetic distance of the Portuguese isolates towards an isolate from China was much lower as compared to an isolate from the USA. This confirmed previous results suggesting an East Asian origin of the Portuguese B. xylophilus.

Bursaphelenchus antoniae sp. n. (Nematoda: Parasitaphelenchidae) associated with Hylobius sp. from Pinus pinaster in Portugal

Abstract: Bursaphelenchus antoniae sp. n. is described and illustrated. Dauer juveniles were isolated from the body of the large pine weevil, Hylobius sp., collected from maritime pine (Pinus pinaster) stumps, in Portugal. Bursaphelenchus antoniae sp. n. was reared and maintained in P. pinaster wood segments and on Petri dish cultures of the fungi Botrytis cinerea and Monilinia fructicola. The new species is characterised by a relatively small body length of ca 583 μ m (females) and 578 μ m (males), a lateral field with two incisures, presence of a small vulval flap and a conoid female tail with a rounded or pointed terminus. Males have stout spicules with a disc-like cucullus and seven caudal papillae arranged as a single midventral precloacal papilla, one precloacal pair and two postcloacal pairs. In the character of the lateral field, B. antoniae sp. n. comes close to B. abietinus, B. rainulfi and B. hylobianum, whilst spicule characters place it within the piniperdae-group sensu Ryss et al. Morphologically, B. antoniae sp. n. is closest to B. hylobianum; the spicules of these two species having flattened, wing-like, alae on the distal third of the lamina. Bursaphelenchus antoniae sp. n. is distinguished from B. hylobianum on the arrangement of the caudal papillae (two vs three pairs). ITS-RFLP profiles and the failure to hybridise support the separation of the two species. Phylogenetic analysis of the new species, based on the 18S rDNA sequence, supports the inclusion of this new species in the B. hylobianum-group sensu Braasch. Sequence analysis of the 28S rDNA D2/D3 domain did not place the new species in a definite group.

Top 10 plant-parasitic nematodes in molecular plant pathology

Abstract: The aim of this review was to undertake a survey of researchers working with plant-parasitic nematodes in order to determine a ‘top 10’ list of these pathogens based on scientific and economic importance. Any such list will not be definitive as economic importance will vary depending on the region of the world in which a researcher is based. However, care was taken to include researchers from as many parts of the world as possible when carrying out the survey. The top 10 list emerging from the survey is composed of: (1) root-knot nematodes (Meloidogyne spp.); (2) cyst nematodes (Heterodera and Globodera spp.); (3) root lesion nematodes (Pratylenchus spp.); (4) the burrowing nematode Radopholus similis; (5) Ditylenchus dipsaci; (6) the pine wilt nematode Bursaphelenchus xylophilus; (7) the reniform nematode Rotylenchulus reniformis; (8) Xiphinema index (the only virus vector nematode to make the list); (9) Nacobbus aberrans; and (10) Aphelenchoides besseyi. The biology of each nematode (or nematode group) is reviewed briefly.

Bark and Wood Boring Insects in Living Trees in Europe, a Synthesis

Abstract: The BAWBILT bases in Europe.- The Bawbilt Context in Europe.- The Directory of European Experts.- The Bawbilt Database.- Damage and Control of Bawbilt Organisms an Overview.- Bark Beetles.- Taxonomy and Systematics of Bark and Ambrosia Beetles.- Genetic Tools in Scolytid Research.- General Biology of Bark Beetles.- Chemical Ecology of Bark Beetles in a Complex Olfactory Landscape.- Host Resistance to Bark Beetles and Its Variations.- Fungal Associates of European Bark Beetles With Special Emphasis on the Ophiostomatoid Fungi.- Research on Parasitoids and Predators of Scolytidae - A Review.- Pathogens in Bark Beetles.- Bark Weevils.- Taxonomy and Systematics of Bark Weevils.- General Biology and Life Cycles of Bark Weevils.- Semiochemicals in the Life of Bark Feeding Weevils.- Hylobius Abietis - Host Utilisation and Resistance.- Fungi Associated With Hylobius Abietis and Other Weevils.- Parasitoids, Predators, Nematodes and Pathogens Associated with Bark Weevil Pests.- Damage, Control and Management of Weevil Pests, Especially Hylobius Abietis.- Buprestids and Longhorns.- Biology, Ecology and Economic Importance of Buprestidae and Cerambycidae.- Natural Enemies of Cerambycidae and Buprestidae Infesting Living Trees.- "Non-Coleopteran" Bawbilt organisms.- "Non-Coleopteran Insects".- Research needs and priorities for Europe.- General Conclusions and Research Priorities for Bawbilt Organisms in Europe.

How much does climate change threaten European forest tree species distributions

Abstract: Although numerous species distribution models have been developed, most were based on insufficient distribution data or used older climate change scenarios. We aimed to quantify changes in projected ranges and threat level by the years 2061-2080, for 12 European forest tree species under three climate change scenarios. We combined tree distribution data from the Global Biodiversity Information Facility, EUFORGEN and forest inventories, and we developed species distribution models using MaxEnt and 19 bioclimatic variables. Models were developed for three climate change scenarios – optimistic (RCP2.6), moderate (RCP4.5) and pessimistic (RPC8.5) – using three General Circulation Models, for the period 2061-2080. Our study revealed different responses of tree species to projected climate change. The species may be divided into three groups: “winners” – mostly late-successional species: Abies alba, Fagus sylvatica, Fraxinus excelsior, Quercus robur and Q. petraea; “losers” – mostly pioneer species: Betula pendula, Larix decidua, Picea abies and Pinus sylvestris and alien species – Pseudotsuga menziesii, Q. rubra and Robinia pseudoacacia, which may be also considered as “winners”. Assuming limited migration, most of the species studied would face significant decrease of suitable habitat area. The threat level was highest for species that currently have the northernmost distribution centers. Ecological consequences of the projected range contractions would be serious for both forest management and nature conservation. This article is protected by copyright. All rights reserved.

Adaptive forest management in central Europe: Climate change impacts, strategies and integrative concept

Abstract: Climatic warming may lead to increased or decreased future forest productivity. However, more frequent heat waves, droughts and storms and accompanying pathogen attacks are also expected for Europe and are considered to be increasingly important abiotic and biotic stress factors for forests. Adaptive forestry can help forest ecosystems to adapt to these new conditions in order to achieve management goals, maintain desired forest ecosystem services and reduce the risks of forest degradation. With a focus on central Europe, this paper presents the following management strategies: (1) conservation of forest structures, (2) active adaptation, and (3) passive adaptation. The feasibility and criteria for application of the different strategies are discussed. Forest adaptation may entail the establishment of “neonative” forests, including the use and intermixing of native and non-native tree species as well as non-local tree provenances that may adapt better to future climate conditions. An integrative ...