Staff Publications

Staff Publications

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    'Staff publications' is the digital repository of Wageningen University & Research

    'Staff publications' contains references to publications authored by Wageningen University staff from 1976 onward.

    Publications authored by the staff of the Research Institutes are available from 1995 onwards.

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European mushroom assemblages are darker in cold climates
Krah, Franz Sebastian ; Büntgen, Ulf ; Schaefer, Hanno ; Müller, Jörg ; Andrew, Carrie ; Boddy, Lynne ; Diez, Jeffrey ; Egli, Simon ; Freckleton, Robert ; Gange, Alan C. ; Halvorsen, Rune ; Heegaard, Einar ; Heideroth, Antje ; Heibl, Christoph ; Heilmann-Clausen, Jacob ; Høiland, Klaus ; Kar, Ritwika ; Kauserud, Håvard ; Kirk, Paul M. ; Kuyper, Thomas W. ; Krisai-Greilhuber, Irmgard ; Norden, Jenni ; Papastefanou, Phillip ; Senn-Irlet, Beatrice ; Bässler, Claus - \ 2019
Nature Communications 10 (2019). - ISSN 2041-1723

Thermal melanism theory states that dark-colored ectotherm organisms are at an advantage at low temperature due to increased warming. This theory is generally supported for ectotherm animals, however, the function of colors in the fungal kingdom is largely unknown. Here, we test whether the color lightness of mushroom assemblages is related to climate using a dataset of 3.2 million observations of 3,054 species across Europe. Consistent with the thermal melanism theory, mushroom assemblages are significantly darker in areas with cold climates. We further show differences in color phenotype between fungal lifestyles and a lifestyle differentiated response to seasonality. These results indicate a more complex ecological role of mushroom colors and suggest functions beyond thermal adaption. Because fungi play a crucial role in terrestrial carbon and nutrient cycles, understanding the links between the thermal environment, functional coloration and species’ geographical distributions will be critical in predicting ecosystem responses to global warming.

Biodiversity recovery of Neotropical secondary forests
Rozendaal, Danaë M.A. ; Bongers, Frans ; Aide, T.M. ; Alvarez-Dávila, Esteban ; Ascarrunz, Nataly ; Balvanera, Patricia ; Becknell, Justin M. ; Bentos, Tony V. ; Brancalion, Pedro H.S. ; Cabral, George A.L. ; Calvo-Rodriguez, Sofia ; Chave, Jerome ; César, Ricardo G. ; Chazdon, Robin L. ; Condit, Richard ; Dallinga, Jorn S. ; Almeida-Cortez, Jarcilene S. De; Jong, Ben de; Oliveira, Alexandre De; Denslow, Julie S. ; Dent, Daisy H. ; Dewalt, Saara J. ; Dupuy, Juan Manuel ; Durán, Sandra M. ; Dutrieux, Loïc P. ; Espírito-Santo, Mario M. ; Fandino, María C. ; Fernandes, G.W. ; Finegan, Bryan ; García, Hernando ; Gonzalez, Noel ; Moser, Vanessa Granda ; Hall, Jefferson S. ; Hernández-Stefanoni, José Luis ; Hubbell, Stephen ; Jakovac, Catarina C. ; Hernández, Alma Johanna ; Junqueira, André B. ; Kennard, Deborah ; Larpin, Denis ; Letcher, Susan G. ; Licona, Juan-Carlos ; Lebrija-trejos, Edwin ; Marín-Spiotta, Erika ; Martínez-Ramos, Miguel ; Massoca, Paulo E.S. ; Meave, Jorge A. ; Mesquita, Rita C.G. ; Mora, Francisco ; Müller, Sandra C. ; Muñoz, Rodrigo ; Oliveira Neto, Silvio Nolasco De; Norden, Natalia ; Nunes, Yule R.F. ; Ochoa-Gaona, Susana ; Ortiz-Malavassi, Edgar ; Ostertag, Rebecca ; Peña-Caros, Marielos ; Pérez-García, Eduardo A. ; Piotto, Daniel ; Powers, Jennifer S. ; Aguilar-Cano, José ; Rodriguez-Buritica, Susana ; Rodríguez-Velázquez, Jorge ; Romero-Romero, Marco Antonio ; Ruíz, Jorge ; Sanchez-Azofeifa, Arturo ; Almeida, Arlete Silva De; Silver, Whendee L. ; Schwartz, Naomi B. ; Thomas, William Wayt ; Toledo, Marisol ; Uriarte, Maria ; Sá Sampaio, Everardo Valadares De; Breugel, Michiel van; Wal, Hans van der; Martins, Sebastião Venâncio ; Veloso, Maria D.M. ; Vester, Hans F.M. ; Vicentini, Alberto ; Vieira, Ima C.G. ; Villa, Pedro ; Williamson, G.B. ; Zanini, Kátia J. ; Zimmerman, Jess ; Poorter, Lourens - \ 2019
Science Advances 5 (2019)3. - ISSN 2375-2548 - 10 p.
Old-growth tropical forests harbor an immense diversity of tree species but are rapidly being cleared, while secondary forests that regrow on abandoned agricultural lands increase in extent. We assess how tree species richness and composition recover during secondary succession across gradients in environmental conditions and anthropogenic disturbance in an unprecedented multisite analysis for the Neotropics. Secondary forests recover remarkably fast in species richness but slowly in species composition. Secondary forests take a median time of five decades to recover the species richness of old-growth forest (80% recovery after 20 years) based on rarefaction analysis. Full recovery of species composition takes centuries (only 34% recovery after 20 years). A dual strategy that maintains both old-growth forests and species-rich secondary forests is therefore crucial for biodiversity conservation in human-modified tropical landscapes.
Multiple successional pathways in human-modified tropical landscapes : New insights from forest succession, forest fragmentation and landscape ecology research
Arroyo-Rodríguez, Víctor ; Melo, Felipe P.L. ; Martínez-Ramos, Miguel ; Bongers, Frans ; Chazdon, Robin L. ; Meave, Jorge A. ; Norden, Natalia ; Santos, Bráulio A. ; Leal, Inara R. ; Tabarelli, Marcelo - \ 2017
Biological Reviews 92 (2017)1. - ISSN 1464-7931 - p. 326 - 340.
Biodiversity conservation - Ecosystem services - Forest recovery - Land-use transformation - Landscape restoration - Landscape structure

Old-growth tropical forests are being extensively deforested and fragmented worldwide. Yet forest recovery through succession has led to an expansion of secondary forests in human-modified tropical landscapes (HMTLs). Secondary forests thus emerge as a potential repository for tropical biodiversity, and also as a source of essential ecosystem functions and services in HMTLs. Such critical roles are controversial, however, as they depend on successional, landscape and socio-economic dynamics, which can vary widely within and across landscapes and regions. Understanding the main drivers of successional pathways of disturbed tropical forests is critically needed for improving management, conservation, and restoration strategies. Here, we combine emerging knowledge from tropical forest succession, forest fragmentation and landscape ecology research to identify the main driving forces shaping successional pathways at different spatial scales. We also explore causal connections between land-use dynamics and the level of predictability of successional pathways, and examine potential implications of such connections to determine the importance of secondary forests for biodiversity conservation in HMTLs. We show that secondary succession (SS) in tropical landscapes is a multifactorial phenomenon affected by a myriad of forces operating at multiple spatio-temporal scales. SS is relatively fast and more predictable in recently modified landscapes and where well-preserved biodiversity-rich native forests are still present in the landscape. Yet the increasing variation in landscape spatial configuration and matrix heterogeneity in landscapes with intermediate levels of disturbance increases the uncertainty of successional pathways. In landscapes that have suffered extensive and intensive human disturbances, however, succession can be slow or arrested, with impoverished assemblages and reduced potential to deliver ecosystem functions and services. We conclude that: (i) succession must be examined using more comprehensive explanatory models, providing information about the forces affecting not only the presence but also the persistence of species and ecological groups, particularly of those taxa expected to be extirpated from HMTLs; (ii) SS research should integrate new aspects from forest fragmentation and landscape ecology research to address accurately the potential of secondary forests to serve as biodiversity repositories; and (iii) secondary forest stands, as a dynamic component of HMTLs, must be incorporated as key elements of conservation planning; i.e. secondary forest stands must be actively managed (e.g. using assisted forest restoration) according to conservation goals at broad spatial scales.

Successional dynamics in Neotropical forests are as uncertain as they are predictable
Norden, Natalia ; Angarita, H.A. ; Bongers, Frans ; Martínez-Ramos, Miguel ; Cerda, I.G. De la; Breugel, Michiel Van; Lebrija-Trejos, Edwin ; Meave, J.A. ; Vandermeer, John ; Williamson, G.B. ; Finegan, Bryan ; Mesquita, Rita ; Chazdon, R.L. - \ 2015
Proceedings of the National Academy of Sciences of the United States of America 112 (2015)26. - ISSN 0027-8424 - p. 8013 - 8018.
Dynamical models - Predictability - Succession - Tropical secondary forests - Uncertainty

Although forest succession has traditionally been approached as a deterministic process, successional trajectories of vegetation change vary widely, even among nearby stands with similar environmental conditions and disturbance histories. Here, we provide the first attempt, to our knowledge, to quantify predictability and uncertainty during succession based on the most extensive long-term datasets ever assembled for Neotropical forests. We develop a novel approach that integrates deterministic and stochastic components into different candidate models describing the dynamical interactions among three widely used and interrelated forest attributes - stem density, basal area, and species density. Within each of the seven study sites, successional trajectories were highly idiosyncratic, even when controlling for prior land use, environment, and initial conditions in these attributes. Plot factors were far more important than stand age in explaining successional trajectories. For each site, the best-fit model was able to capture the complete set of time series in certain attributes only when both the deterministic and stochastic components were set to similar magnitudes. Surprisingly, predictability of stem density, basal area, and species density did not show consistent trends across attributes, study sites, or land use history, and was independent of plot size and time series length. The model developed here represents the best approach, to date, for characterizing autogenic successional dynamics and demonstrates the low predictability of successional trajectories. These high levels of uncertainty suggest that the impacts of allogenic factors on rates of change during tropical forest succession are far more pervasive than previously thought, challenging the way ecologists view and investigate forest regeneration.

Environmental gradients and the evolution of successional habitat specialization : A test case with 14 Neotropical forest sites
Letcher, Susan G. ; Lasky, Jesse R. ; Chazdon, Robin L. ; Norden, Natalia ; Wright, S.J. ; Meave, Jorge A. ; Pérez-García, Eduardo A. ; Muñoz, Rodrigo ; Romero-Pérez, Eunice ; Andrade, Ana ; Balvanera, Patricia ; Bongers, Frans ; Lohbeck, Madelon - \ 2015
Journal of Ecology 103 (2015)5. - ISSN 0022-0477 - p. 1276 - 1290.
Determinants of plant community diversity and structure - Functional traits - Life-history evolution - Phylogeny - Pioneer species - Precipitation gradient - Tropical dry forest - Tropical wet forest

Successional gradients are ubiquitous in nature, yet few studies have systematically examined the evolutionary origins of taxa that specialize at different successional stages. Here we quantify successional habitat specialization in Neotropical forest trees and evaluate its evolutionary lability along a precipitation gradient. Theoretically, successional habitat specialization should be more evolutionarily conserved in wet forests than in dry forests due to more extreme microenvironmental differentiation between early and late-successional stages in wet forest. We applied a robust multinomial classification model to samples of primary and secondary forest trees from 14 Neotropical lowland forest sites spanning a precipitation gradient from 788 to 4000 mm annual rainfall, identifying species that are old-growth specialists and secondary forest specialists in each site. We constructed phylogenies for the classified taxa at each site and for the entire set of classified taxa and tested whether successional habitat specialization is phylogenetically conserved. We further investigated differences in the functional traits of species specializing in secondary vs. old-growth forest along the precipitation gradient, expecting different trait associations with secondary forest specialists in wet vs. dry forests since water availability is more limiting in dry forests and light availability more limiting in wet forests. Successional habitat specialization is non-randomly distributed in the angiosperm phylogeny, with a tendency towards phylogenetic conservatism overall and a trend towards stronger conservatism in wet forests than in dry forests. However, the specialists come from all the major branches of the angiosperm phylogeny, and very few functional traits showed any consistent relationships with successional habitat specialization in either wet or dry forests. Synthesis. The niche conservatism evident in the habitat specialization of Neotropical trees suggests a role for radiation into different successional habitats in the evolution of species-rich genera, though the diversity of functional traits that lead to success in different successional habitats complicates analyses at the community scale. Examining the distribution of particular lineages with respect to successional gradients may provide more insight into the role of successional habitat specialization in the evolution of species-rich taxa.

Ecosystem Services and Opportunity Costs Shift Spatial Priorities for Conserving Forest Biodiversity
Schroter, M. ; Rusch, G.M. ; Barton, D.N. ; Blumentrath, S. ; Nordén, B. - \ 2014
PLoS ONE 9 (2014)11. - ISSN 1932-6203 - 12 p.
protected areas - trade-offs - rich forests - conservation - landscapes - strategies - payments - benefits - science - norway
Inclusion of spatially explicit information on ecosystem services in conservation planning is a fairly new practice. This study analyses how the incorporation of ecosystem services as conservation features can affect conservation of forest biodiversity and how different opportunity cost constraints can change spatial priorities for conservation. We created spatially explicit cost-effective conservation scenarios for 59 forest biodiversity features and five ecosystem services in the county of Telemark (Norway) with the help of the heuristic optimisation planning software, Marxan with Zones. We combined a mix of conservation instruments where forestry is either completely (non-use zone) or partially restricted (partial use zone). Opportunity costs were measured in terms of foregone timber harvest, an important provisioning service in Telemark. Including a number of ecosystem services shifted priority conservation sites compared to a case where only biodiversity was considered, and increased the area of both the partial (+36.2%) and the non-use zone (+3.2%). Furthermore, opportunity costs increased (+6.6%), which suggests that ecosystem services may not be a side-benefit of biodiversity conservation in this area. Opportunity cost levels were systematically changed to analyse their effect on spatial conservation priorities. Conservation of biodiversity and ecosystem services trades off against timber harvest. Currently designated nature reserves and landscape protection areas achieve a very low proportion (9.1%) of the conservation targets we set in our scenario, which illustrates the high importance given to timber production at present. A trade-off curve indicated that large marginal increases in conservation target achievement are possible when the budget for conservation is increased. Forty percent of the maximum hypothetical opportunity costs would yield an average conservation target achievement of 79%.
Konflikt und Kooperation bei der Wassernutzung in Mittelasien
Wegerich, K. - \ 2009
Wissenschaft und Frieden 4 (2009). - ISSN 0947-3971 - p. 22 - 26.
In Mittelasien sind Mensch, Natur und Wirtschaft auf das Wasser zweier Flusssysteme angewiesen: des Syr Darja im Norden und des Amu Darja im Süden. Beide Ströme sind in hohem Maße zur Stromgewinnung und landwirtschaftlichen Bewässerung erschlossen. Die Nutzung des Wassers birgt erhebliches Potential sowohl für Konflikte als auch für Kooperationen zwischen den einzelnen Anrainerstaaten: Am Oberlauf wollen sie die Wasserkraft zur Stromerzeugung nutzen, am Unterlauf sehen sie die Bewässerung ihrer Felder in Gefahr
Above-ground biomass and productivity in a rain forest of eastern South America
Chave, J. ; Olivier, J. ; Bongers, F.J.J.M. ; Chatelet, P. ; Forget, P.M. ; Meer, P.J. van der; Norden, N. ; Riera, B. ; Charles-Dominique, P. - \ 2008
Journal of Tropical Ecology 24 (2008). - ISSN 0266-4674 - p. 355 - 366.
net primary production - wood specific-gravity - long-term plots - tropical forests - french-guiana - neotropical forest - live biomass - carbon - amazon - density
Abstract: The dynamics of tropical forest woody plants was studied at the Nouragues Field Station, central French Guiana. Stem density, basal area, above-ground biomass and above-ground net primary productivity, including the contribution of litterfall, were estimated from two large permanent census plots of 12 and 10 ha, established on contrasting soil types, and censused twice, first in 1992¿1994, then again in 2000¿2002. Mean stem density was 512 stems ha¿1 and basal area, 30m2 ha¿1. Stem mortality rate ranged between 1.51% and 2.06% y¿1. In both plots, stem density decreased over the study period. Using a correlation between wood density and wood hardness directly measured by a Pilodyn wood tester,we found that the mean wood densitywas 0.63 g cm¿3, 12% smaller than the mean of wood density estimated from the literature values for the species occurring in our plot. Above-ground biomass ranged from 356 to 398Mgha¿1 (oven-dry mass), and it increased over the census period. Leaf biomass was 6.47Mg ha¿1. Our total estimate of aboveground net primary productivity was 8.81 MgC ha¿1 y¿1 (in carbon units), not accounting for loss to herbivory, branchfalls, or biogenic volatile organic compounds, whichmay altogether account for an additional 1MgC ha¿1 y¿1. Coarse wood productivity (stem growth plus recruitment) contributed to 4.16 MgC ha¿1 y¿1. Litterfall contributed to 4.65MgC ha¿1 y¿1 with 3.16 MgC ha¿1 y¿1 due to leaves, 1.10 MgC ha¿1 y¿1 to twigs, and 0.39MgC ha¿1 y¿1 to fruits and flowers. The increase in above-ground biomass for both trees and lianas is consistentwith the hypothesis of a shift in the functioning of Amazonian rain forests driven by environmental changes, although alternative hypotheses such as a recovery from past disturbances cannot be ruled out at our site, as suggested by the observed decrease in stem density. Key Words: above-ground biomass, carbon, French Guiana, net primary productivity, tropical forest
Strengths and weaknesses of phosphorus models: EUROHARP: short summary
Schoumans, O.F. - \ 2005
In: Tools for assessing phosphorus loss from Nordic agriculture / Heckrath, G., Bechmann, M., Ekholm, P., Djodjic, F., Ulén, B., Andersen, H.E., Olsen, P., Copenhagen (Denmark) : Norden (TemaNord 2005:583) - p. 41 - 46.
The genetics of non-host resistance to the lettuce pathogen Bremia lactucae in Lactuca saligna
Jeuken, M.J.W. - \ 2002
Wageningen University. Promotor(en): P. Stam; P. Lindhout. - S.l. : S.n. - ISBN 9789058086198 - 120
lactuca sativa - lactuca saligna - bremia lactucae - moleculaire genetica - genetische merkers - complexe loci - meeldauw - plantenziekten - genetisch bepaalde resistentie - ziekteresistentie - selectie - genetische kartering - lactuca sativa - lactuca saligna - bremia lactucae - molecular genetics - genetic markers - complex loci - mildews - plant diseases - genetic resistance - disease resistance - selection - genetic mapping

Plants are continuously exposed to a wide variety of pathogens. However, all plant species are non-hosts for the majority of the potential plant pathogens. The genetic dissection of non-host resistance is hampered by the lack of segregating population from crosses between host and non-host species, since hardly any non-host is crossable with a host. We have studied the non-host resistance in Lactuca saligna (wild lettuce) to lettuce downy mildew ( Bremia lactucae ). L. saligna is one of the few examples of a non-host species that is crossable with a related host species, L. sativa (lettuce). Based on this interspecific cross, segregating populations have been developed for genetical analysis of the non-host resistance. To map the resistance, we have used two strategies in which we make use of DNA markers to genotype plants. As no accurate linkage map was available for lettuce, we started with the construction of a linkage map of L. saligna´L. sativa . In Chapter 2, the development of an integrated linkage map, based on two populations, is described. To acquire DNA markers, AFLP analyses have been performed on the F 2 populations of the crosses L. saligna CGN 5271 ´L. sativa Olof and L. saligna CGN 11341´L. sativa Norden. Based on these AFLP analyses the polymorphism rate between L. saligna and L. sativa is estimated to be 81%. A linkage map was constructed that comprises 12 SSRs and 476 AFLP markers over 854 cM in nine linkage groups (n=9). Since the markers are randomly spread over all chromosomes, we assume this map is an accurate representative of both parental genomes and very useful for Marker Assisted Selection.

The first mapping strategy for downy mildew resistance is described in Chapter 3. In that study, we have performed a QTL analysis on 126 F 2 plants of a cross between the resistant L. saligna CGN 5271 and the susceptible L. sativa Olof. For this QTL analysis all 126 F 2 plants have been tested for resistance in four disease tests with two complex Bremia races (NL14 and NL16). The F 2 population showed a wide and continuous range of resistance levels from completely resistant to completely susceptible. Evidence is presented for a quantitative resistance against both Bremia races as well as for a race-specific resistance against Bremia race NL16 and not against NL14. These disease test data sets have been combined with DNA marker data of all 126 F 2 plants that had already been obtained for the construction of the linkage map. QTL mapping revealed a qualitative gene ( R39 ) explaining the race-specific resistance and three QTLs ( RBQ1 , RBQ2 and RBQ3 ) explaining the quantitative resistance. The qualitative gene R39 is a dominant gene that gives nearly complete resistance to race NL16 in L. saligna CGN 5271 and therefore it shows features similar to Dm genes (dominant race specific genes that give a complete resistance to d owny m ildew). The three QTLs explain 51% of the quantitative resistance against NL14, which indicates that probably not all QTLs have been detected in this F 2 population.

In addition to this rather classical F 2 mapping strategy, we have performed an alternative mapping strategy based on the development and characterization of a set of Backcross Inbred Lines (BILs). These BILs are genetically nearly completely like L. sativa but contain a single chromosome substitution segment of L. saligna CGN 5271 (Chapter 4). Starting from an F 1 plant, BILs have been developed by four to five generations of backcrosses and one generation of selfing. All backcrosses from F 1 to BC 4 were made randomly without intentional selection. Marker Assisted Selection was started in the BC 4 generation. Finally, a set of 29 lines was obtained that covers 95% of the L. saligna genome, comprising 16 lines with a single homozygous introgression (BILs), one line with two homozygous introgressions, five lines with heterozygous single introgressions and seven lines with two or more heterozygous introgressions. Several chromosome regions showed severe distorted segregation in the F 2 population. Based on segregation ratios in backcross lines, we were able to explain distorted segregations of three chromosome regions observed in the F 2 population by genetic loci that are involved in pollen- or egg cell fitness.

When seed of the first developed BILs was available, a disease test had been set up to test if the BILs, which carried QTLs as identified in the F 2 population, showed enhanced levels of quantitative resistance indeed. Nine BILs (or nearly-BILs) have been tested for resistance to Bremia race NL16. They covered together 31% of the L. saligna parental genome. Two resistance loci detected in the F 2 population ( R39 and RBQ3 ) have been confirmed in the disease test on the BILs. R39 is a dominant gene, which gives a complete resistance against Bremia race NL16. RBQ3 reduces the infection severity of the susceptible L. sativa by 49% ten days post inoculation. The quantitative effects from the resistance genes in these BILs were higher than expected from the F 2 mapping results. No conclusive comparisons of RBQ2 could have been made, as the introgression in the backcross line was not homozygous. RBQ1 has not been tested. Most exciting, the BIL method revealed a new resistance locus on Chromosome 8 with a 77% reduction on the infection severity compared to the susceptible control ten days post inoculation. We conclude that the BIL mapping method can reveal new QTLs unnoticed in the F 2 mapping method and it enables a quantification of the resistance gene effect in a L. sativa background.

To extend our knowledge about the non-host resistance of L. saligna to Bremia , we have compared the genetics of non-host resistance to Bremia in L. saligna CGN 5271 with another accession L. saligna CGN 11341. The two accessions show a 39% AFLP polymorphism rate. We have analyzed the non-host resistance of L. saligna CGN 11341 by disease tests and DNA marker analyses on an F 2 and BC 1 population. Disease tests with Bremia races NL14 and NL16 showed a wide range of infection severity scores from resistant to susceptible to both races. The majority of plants had a similar resistance level to both Bremia races. These findings imply that the resistance of L. saligna is quantitatively expressed and is probably race non-specific. A few F 2 and BC 1 plants were completely resistant against Bremia race NL16 and rather susceptible to race NL14. QTL mapping revealed that a major resistance gene that was located on Chromosome 9 explains this race-specific resistance. This gene is designated R39b , as it may be different from R39 .

No additional QTLs have been detected in this small F 2 population (n= 54). However, F 2 plants with L. saligna CGN 11341 alleles at loci of RBQ1 , RBQ2 , RBQ3 and RBQ4 mapped in L. saligna CGN 5271, were more resistant than F 2 plants with L. sativa alleles at these loci. In conclusion, we state that it is very likely that the same genes explain the resistances to Bremia in both L. saligna accessions. A backcross program for a set of Backcross Inbred Lines (BIL) that cover R39b and loci for putative QTLs, is in progress.

In the last chapter of this thesis the basic results of the study have been discussed. We adduce that non-host resistance in L. saligna is not explained by accumulation of race-specific major resistance genes ( Dm genes) but by a resistance mechanism based on QTLs. Further, we have made a comparison for efficiency of four breeding methods to introgress the resistance genes from L. saligna . Based on this study, we conclude that twice as many resistance genes are introgressed when Marker Assisted Selection is used. Finally, several recommendations concerning research on non-host resistance and the applications of Backcross Inbred Lines have been suggested.

Red List of Birds of the Wadden Sea
Rasmussen, L.M. ; Norden Andersen, O.G. ; Frikke, J. ; Laursen, K. ; Salvig, J. ; Fleet, D.M. ; Hälterlein, B. ; Heckenroth, H. ; Merck, T. ; Rösner, H.U. ; Südbeck, P. ; Wolff, W.J. ; Thissen, J.B.M. - \ 1996
Helgoländer Meeresuntersuchungen 50 (1996)suppl.. - ISSN 0174-3597 - p. 113 - 128.
Adhesion of bacteria, a physico-chemical interpretation.
Loosdrecht, M.C.M. van; Norden, W. ; Zehnder, A.J.B. - \ 1986
ISME Journal (1986). - ISSN 1751-7362 - p. 121 - 121.
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