Staff Publications

Staff Publications

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    '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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    Co-evolution between Globodera rostochiensis and potato driving sequence diversity of NB-LRR resistance loci and nematode suppressors of plant immunity
    Finkers-Tomczak, A.M. - \ 2011
    Wageningen University. Promotor(en): Jaap Bakker, co-promotor(en): Aska Goverse; Geert Smant. - [S.l.] : S.n. - ISBN 9789085859499 - 200
    solanaceae - solanum tuberosum - plaagresistentie - loci voor kwantitatief kenmerk - genen - plantenparasitaire nematoden - globodera rostochiensis - globodera pallida - co-evolutie - genetische kartering - solanaceae - solanum tuberosum - pest resistance - quantitative trait loci - genes - plant parasitic nematodes - globodera rostochiensis - globodera pallida - coevolution - genetic mapping

    Sedentary plant parasitic nematodes have evolved sophisticated strategies that allow them to transform host cells in the roots of host plants into feeding structures. These complex structures enable the nematodes to complete their life cycle inside a single host plant. Feeding structure initiation and maintenance are thought to be determined by the concerted action of effectors produced by the esophageal glands of the nematodes. However, the molecular mechanisms underlying the transformation of host cells into feeding structures and the role of the effectors in this process are poorly understood. For example, it is generally thought that virulent nematodes also use effectors to protect their complex feeding structures from plant innate immune responses. However, nematode effectors suppressing plant innate immunity have not been identified to date.

    The host ranges of sedentary plant parasitic nematodes can vary from very wide (e.g. root-knot nematodes) to relatively narrow, limited to single plant families (e.g. cyst nematodes). Potato cyst nematodes (PCN) are able to parasitize only Solanaceous plants. Every year, they cause substantial yield losses in potato production areas. PCN are very difficult to control by the use of cultivation methods or the application of pesticides alone. The introduction of novel nematode resistant potato cultivars to the market is therefore of great importance for potato growers all over the world. Resistances, however, can be overcome by the emergence of virulent nematode populations. The aim of this thesis is to study incompatible interactions between the potato cyst nematode Globodera rostochiensis and potato (Solanum tuberosum), by analyzing resistance loci that make the plant immune to potato cyst nematodes as well as nematode effectors that suppress plant innate immunity.

    This thesis begins with an extensive review of the literature on molecular and cellular aspects of plant resistance to sedentary endoparasitic nematodes, including pre-infectional, non-host and host resistance (Chapter 2). Most research in this field has focused on host resistance to nematodes, which is determined by single (e.g.H1 and Gpa2) or multiple (e.g. GpaVSsplandGpaXISspl) resistance gene loci. Two potato cyst nematode resistance loci were studied in this thesis (i.e. Grp1 in Chapter 3 and H1 in Chapter 4) and the results of these studies are summarized below.

    Grp1 locus confers broad-spectrum quantitative resistance to the potato cyst nematode species Globodera pallida and G. rostochiensis in potato. It was previously mapped to a 3 cM interval on the short arm of potato chromosome V between the markers GP21 and GP179 in a hot spot for resistance (Rouppe Van Der Voort et al., 1998). The aim of the work described in chapter 3 was to fine map the Grp1 locus. First, a diploid mapping population RHAM026, comprising 1536 genotypes was screened with the flanking markers GP21 and GP179, resulting in the identification of 61 recombinants in this region. Next, thirteen new markers were developed using the genomic sequence information available from the same region of Solanum demissum. Together with markers available from the literature, these thirteen markers were used to screen a subset of 54 recombinants. Finally, these recombinants were tested for resistance to G. pallida Pa2 and G. rostochiensis Ro5. This mapping of both resistance specificities resulted in two nearly identical LOD graphs with the highest score just north of marker TG432. We conclude that the resistances to both G. pallida and G. rostochiensis map to the same 1.08 cM interval between the markers SPUD838 and TG432. Other studies have revealed that this locus in potato harbors several gene clusters encoding classical NB-ARC-LRR resistance proteins. This finding led us to the hypothesis that the Grp1 resistance depends on one, or perhaps several tightly linked major genes.

    Near-absolute resistance to G. rostochiensis pathotypes 1 and 4 is conferred by the H1 resistance locus at the distal end of chromosome V of the diploid S. tuberosum ssp. andigena genotype SH83-92-488 (SH). The H1 resistance involves a hypersensitive response in the cells surrounding the nematode feeding structure, so that it becomes isolated from the vascular tissues in the host. A high-resolution map of H1 locus was generated previously using SHxRH mapping population (Bakker et al., 2004). In chapter 4, we used markers from thismap to screen a BAC library of SH. The BAC inserts identified with the markers were used to construct a physical map covering this region in the resistant haplotype. Further sequencing of the BAC inserts, included in the physical map, revealed a genomic fragment of 341 Kb harboring a large cluster of CC-NB-ARC-LRR genes. We compared this cluster of resistance gene homologs with the sequences of the corresponding regions in the two susceptible haplotypes from the diploid genotype RH89-039-16 (S. tuberosum ssp. tuberosum/ S. phureja), spanning 700 and 319 Kb respectively. The genomic regions in all three haplotypes harbor from 17 up to 23 resistance gene homologs interspersed with numerous transposable elements, genes coding for extensin-like proteins, and an amino acid transporter. Strikingly, the three haplotypes do not reveal gene order conservation and the overall sequence homology is only confined to the coding sequences of the resistance gene homologs. These findings suggest that extensive rearrangements have shaped the H1 locus. Sequence data and marker information gained from this study will benefit future efforts to clone the H1 nematode resistance gene.

    At the start of the research described in this thesis no suppressor of plant immune response had been found in plant parasitic nematodes. In chapter 5, we report the first identification and functional characterization of a G. rostochiensis effector suppressing plant innate immune responses. The Nematode Suppressors of Immunity 1 (NSI-1) are specifically expressed in the dorsal esophageal gland of the nematodes, and their expression is upregulated in stages that feed on host cells. We identified many variants of NSI-1 in the Ro1-Mierenbos field population, and showed that this gene family is under diversifying selection. Knocking-down NSI-1 transcription by RNA interference strongly reduced the number of nematodes developing into full-grown cysts. Overexpression of four NSI-1 variants in susceptible potato plants resulted in enhanced susceptibility to nematodes. Moreover, overexpression of three other variants enhanced the susceptibility of potato plants to the fungus Verticillium dahliae. Down-regulation of the potato homologs of the Arabidopsis thaliana transcription factors WRKY22 and WRKY53 in these plants indicated that NSI-1 target immune signaling in plants. In an agroinfiltration assay in leaves of Nicotiana benthamiana several NSI-1 variants suppressed the hypersensitive response caused by the co-expression of specific resistance proteins and matching pathogen effectors (i.e. RBP-1/Gpa2 and AvrBlb2/Rpi-blb2) and by autoactive mutants of the resistance protein Mi-1.2 and an H1 resistance gene homolog RGH10-H1. Interestingly, other NSI-1 effector variant suppressed the hypersensitivity response induced by an autoactive mutant of the immune signaling protein NRC1. These findings altogether lead to the conclusion that potato cyst nematodes secrete suppressors of plant immunity, most likely to protect their feeding structures.

    In the final chapter of this thesis, we discuss our most important findings within the broader context of recent developments in the field of molecular plant-microbe interactions. First, we argue that quantitative nematode resistance Grp1 is encoded by one or more NB-ARC-LRR genes located in one of the resistance gene clusters mapped to the GP21-GP179 interval on potato chromosome V. We further examine obstacles and offer possible solutions with regard to future cloning of the H1 nematode resistance gene. Lastly, we elaborate on possible functions, activities, and evolution of NSI-1 effectors as suppressors of plant innate immunity.

    Construction of a 10,000-marker ultradense genetic recombination map of potato: providing a framework for accelerated gene isolation and a genomewide physical map
    Os, H. van; Andrzejewski, S. ; Bakker, E.H. ; Barrena, I. ; Bryan, G.J. ; Caromel, B. ; Ghareeb, B. ; Isidore, E. ; Jong, W. de; Koert, P. van; Lefebvre, V. ; Milbourne, D. ; Ritter, E. ; Rouppe van der Voort, J.N.A.M. ; Rousselle-Bourgeois, F. ; Vliet, J.M. van; Waugh, R. ; Visser, R.G.F. ; Bakker, J. ; Eck, H.J. van - \ 2006
    Genetics 173 (2006)2. - ISSN 0016-6731 - p. 1075 - 1087.
    quantitative trait loci - sequence-tagged sites - solanum-tuberosum - linkage map - resistance-gene - aflp markers - mapping strategy - density - tomato - populations
    An ultradense genetic linkage map with >10,000 AFLP loci was constructed from a heterozygous diploid potato population. To our knowledge, this is the densest meiotic recombination map ever constructed. A fast marker-ordering algorithm was used, based on the minimization of the total number of recombination events within a given marker order in combination with genotyping error-detection software. This resulted in "skeleton bin maps," which can be viewed as the most parsimonious marker order. The unit of distance is not expressed in centimorgans but in "bins." A bin is a position on the genetic map with a unique segregation pattern that is separated from adjacent bins by a single recombination event. Putative centromeres were identified by a strong clustering of markers, probably due to cold spots for recombination. Conversely, recombination hot spots resulted in large intervals of up to 15 cM without markers. The current level of marker saturation suggests that marker density is proportional to physical distance and independent of recombination frequency. Most chromatids (92%) recombined once or never, suggesting strong chiasma interference. Absolute chiasma interference within a chromosome arm could not be demonstrated. Two examples of contig construction and map-based cloning have demonstrated that the marker spacing was in accordance with the expected physical distance: approximately one marker per BAC length. Currently, the markers are used for genetic anchoring of a physical map of potato to deliver a sequence-ready minimal tiling path of BAC contigs of specific chromosomal regions for the potato genome sequencing consortium (
    Molecular markers for resistance to cyst nematodes in potato
    Bakker, E.H. ; Rouppe van der Voort, J.N.A.M. ; Eck, H.J. van; Hutten, R.C.B. ; Bakker, J. ; Goverse, A. - \ 2004
    In: Nematology Monographs and Perspectives: Proceedings of the Fourth International Congress of Nematology 8-13 June 2002, Tenerife, Spain / Cook, R.C., Hunt, D.J., Leiden : Brill - ISBN 9789004139213 - p. 211 - 217.
    An EU project on gene flow analysis between crop and wild forms of lettuce and chicory in the context of GMO biosafety: first results in lettuce
    Wiel, C.C.M. van de; Linden, C.G. van der; Nijs, H.C.M. den; Flavell, A. ; Syed, N. ; Jorgensen, R.B. ; Felber, F. ; Scotti, I. ; Rouppe van der Voort, J.N.A.M. ; Peleman, J. - \ 2003
    In: Proceedings of the Eucarpia meeting on leafy vegetables genetics and breeding, Noordwijkerhout, The Netherlands, 19 - 21 March, 2003. - Wageningen : Centre for Genetic Resources - p. 111 - 116.
    Toward a marker-dense meiotic map of the potato genome: lessons from linkage group I
    Isidore, E. ; Os, H. van; Andrzejewski, S. ; Bakker, J. ; Barrena, I. ; Bryan, G.J. ; Caromel, B. ; Eck, H.J. van; Ghareeb, B. ; Jong, W. de; Koert, P. van; Lefebvre, V. ; Milbourne, D. ; Ritter, E. ; Rouppe van der Voort, J.N.A.M. ; Rousselle-Bourgeois, F. ; Vliet, J.M. van; Waugh, R. - \ 2003
    Genetics 165 (2003). - ISSN 0016-6731 - p. 2107 - 2116.
    comprehensive genetic-map - comigrating aflp markers - dna methylation - lycopersicon-esculentum - tomato - plants - resistance - construction - population - strategy
    Segregation data were obtained for 1260 potato linkage group I-specific AFLP loci from a heterozygous diploid potato population. Analytical tools that identified potential typing errors and/or inconsistencies in the data and that assembled cosegregating markers into bins were applied. Bins contain multiple-marker data sets with an identical segregation pattern, which is defined as the bin signature. The bin signatures were used to construct a skeleton bin map that was based solely on observed recombination events. Markers that did not match any of the bin signatures exactly (and that were excluded from the calculation of the skeleton bin map) were placed on the map by maximum likelihood. The resulting maternal and paternal maps consisted of 95 and 101 bins, respectively. Markers derived from EcoRI/MseI, PstI/MseI, and SacI/MseI primer combinations showed different genetic distributions. Approximately three-fourths of the markers placed into a bin were considered to fit well on the basis of an estimated residual "error rate" of 0-3%. However, twice as many PstI-based markers fit badly, suggesting that parental PsiI-site methylation patterns had changed in the population. Recombination frequencies were highly variable across the map. Inert, presumably centromeric, regions caused extensive marker clustering while recombination hotspots (or regions identical by descent) resulted in empty bins, despite the level of marker saturation.
    Genetic and physical mapping of homologues of the virus resistance gene Rx1 and the cyst nematode resistance gene Gpa2 in potato.
    Bakker, E.H. ; Butterbach, P.B.E. ; Rouppe van der Voort, J.N.A.M. ; Vossen, E.A.G. van der; Vliet, J.M. van; Bakker, J. ; Goverse, A. - \ 2003
    Theoretical and Applied Genetics 106 (2003)8. - ISSN 0040-5752 - p. 1524 - 1531.
    Nine resistance gene homologues (RGHs) were identified in two diploid potato clones (SH and RH), with a specific primer pair based on conserved motifs in the LRR domain of the potato cyst nematode resistance gene Gpa2 and the potato virus X resistance gene Rx1. A modified AFLP method was used to facilitate the genetic mapping of the RGHs in the four haplotypes under investigation. All nine RGHs appeared to be located in the Gpa2/Rx1 cluster on chromosome XII. Construction of a physical map using bacterial artificial chromosome (BAC) clones for both the Solanum tuberosum ssp. tuberosum and the S. tuberosum ssp. andigena haplotype of SH showed that the RGHs are located within a stretch of less than 200 kb. Sequence analysis of the RGHs revealed that they are highly similar (93 to 95%) to Gpa2 and Rx1. The sequence identities among all RGHs range from 85 to 100%. Two pairs of RGHs are identical, or nearly so (100 and 99.9%), with each member located in a different genotype. Southern-blot analysis on genomic DNA revealed no evidence for additional homologues outside the Gpa2/Rx1 cluster on chromosome XII.
    The effects of founding events and agricultural practices on the genetic structure of three metapopulations of Globodera pallida
    Folkertsma, R.T. ; Koert, P. van; Rouppe van der Voort, J.N.A.M. ; Groot, K.E. de; Kammenga, J.E. ; Helder, J. ; Bakker, J. - \ 2001
    Phytopathology 91 (2001)8. - ISSN 0031-949X - p. 753 - 758.
    An efficient cDNA-AFLP based strategy for the identification of putative pathogenicity factors from the potato cyst nematode Globodera rostochiensis
    Qin Ling, ; Overmars, H. ; Smant, G. ; Rouppe van der Voort, J.N.A.M. ; Koert, P. van; Schots, A. ; Bakker, J. ; Helder, J. - \ 2000
    In: Programs and abstracts of the thirty-ninth annual meeting : Society of nematologists, Québec 2000. - Québec : s.n., 2000 - p. 60 - 60.
    An efficient cDNA-AFLP based strategy for the identification of putative pathogenicity factors from the potato cyst nematode Globodera rostochiensis
    Qin Ling, ; Overmars, H. ; Smant, G. ; Rouppe van der Voort, J.N.A.M. ; Koert, P. van; Schots, A. ; Bakker, J. ; Helder, J. - \ 2000
    In: Book of Abstracts ISPMB : 6th International Congress of Plant Molecular Biology, Québec, Canada 2000. - Québec : s.n., 2000 - p. S22 - 80.
    Homologues of a single resistance-gene cluster in potato confer resistance to distinct pathogens: a virus and a nematode
    Vossen, E.A.G. van der; Rouppe van der Voort, J. ; Kanyuka, K. ; Bendahmane, A. ; Sandbrink, H. ; Baulcombe, D.C. ; Bakker, J. ; Stiekema, W.J. ; Klein-Lankhorst, R.M. - \ 2000
    The Plant Journal 23 (2000). - ISSN 0960-7412 - p. 567 - 576.
    The isolation of the nematode-resistance gene Gpa2 in potato is described, and it is demonstrated that highly homologous resistance genes of a single resistance-gene cluster can confer resistance to distinct pathogen species. Molecular analysis of the Gpa2 locus resulted in the identification of an R-gene cluster of four highly homologous genes in a region of approximately 115 kb. At least two of these genes are active: one corresponds to the previously isolated Rx1 gene that confers resistance to potato virus X, while the other corresponds to the Gpa2 gene that confers resistance to the potato cyst nematode Globodera pallida. The proteins encoded by the Gpa2 and the Rx1 genes share an overall homology of over 88øamino-acid identity) and belong to the leucine-zipper, nucleotide-binding site, leucine-rich repeat (LZ-NBS-LRR)-containing class of plant resistance genes. From the sequence conservation between Gpa2 and Rx1 it is clear that there is a direct evolutionary relationship between the two proteins. Sequence diversity is concentrated in the LRR region and in the C-terminus. The putative effector domains are more conserved suggesting that, at least in this case, nematode and virus resistance cascades could share common components. These findings underline the potential of protein breeding for engineering new resistance specificities against plant pathogens in vitro.
    An efficient cDNA-AFLP based strategy for the identification of putative pathogenicity factors from the potato cyst nematode Globodera rostochiensis
    Qin Ling, ; Overmars, H. ; Helder, J. ; Popeijus, H. ; Rouppe van der Voort, J. ; Groenink, W. ; Koert, P. van; Schots, A. ; Bakker, J. ; Smant, G. - \ 2000
    Molecular Plant-Microbe Interactions 13 (2000)8. - ISSN 0894-0282 - p. 830 - 836.
    A new strategy has been designed to identify putative pathogenicity factors from the dorsal or subventral esophageal glands of the potato cyst nematode Globodera rostochiensis. Three independent criteria were used for selection. First, genes of interest should predominantly be expressed in infective second-stage juveniles, and not, or to a far lesser extent, in younger developmental stages. For this, gene expression profiles from five different developmental stages were generated with cDNA-AFLP (amplified fragment length polymorphism). Secondly, the mRNA corresponding to such a putative pathogenicity factor should predominantly be present in the esophageal glands of pre-parasitic juveniles. This was checked by in situ hybridization. As a third criterion, these proteinaceous factors should be preceded by a signal peptide for secretion. Expression profiles of more than 4,000 genes were generated and three up-regulated, dorsal gland-specific proteins preceded by signal peptide for secretion were identified. No dorsal gland genes have been cloned before from plant-parasitic nematodes. The partial sequence of these three factors, A4, A18, and A41, showed no significant homology to any known gene. Their presence in the dorsal glands of infective juveniles suggests that these proteins could be involved in feeding cell initiation, and not in migration in the plant root or in protection against plant defense responses. Finally, the applicability of this new strategy in other plant-microbe interactions is discussed.
    Two additive QTLs conferring broad-spectrum resistance in potato to Globodera pallida are localized on resistance gene clusters
    Rouppe van der Voort, J. ; Vossen, E. van der; Bakker, E. ; Overmars, H. ; Zandvoort, P. van; Hutten, R. ; Klein Lankhorst, R. ; Bakker, J. - \ 2000
    Theoretical and Applied Genetics 101 (2000). - ISSN 0040-5752 - p. 1122 - 1130.
    Broad-spectrum resistance in potato to the potato cyst nematode (PCN) is commonly regarded as a complex inherited trait. Yet, in this paper we show that, by use of a selected set of PCN test populations, broad-spectrum resistance to the species Globodera pallida can be fully ascribed to the action of two loci: Gpa5 and Gpa6. These loci were readily mapped by means of a strategy based on two steps. Firstly, the chromosomal localization of both loci was assessed by use of an online catalogue of AFLP markers covering a substantial part of the potato genome ( Subsequently the chromosomal regions of both loci were identified by means of CAPS markers based on RFLP insert sequences. Locus Gpa5 explains at least 61% of the genetic variation. This locus maps to chromosome 5 on a region which has previously been shown to harbor resistance factors to viral (Nb, Rx2), fungal (R1) and nematodal (Gpa, Grp1) pathogens. The Gpa6 locus exhibits a minor effect on the resistance (24%) and acts additively to Gpa5. Interestingly, the Gpa6 locus maps to a region on chromosome 9 where, in the homoeologous tomato genome, the virus resistance gene Sw-5 resides as part of a resistance gene cluster. In potato, resistance to potato virus X has been reported in the vicinity of this region. The map location of Gpa6 indicates the presence of a resistance gene cluster at the end of the long arm of chromosome 9 of potato.
    A novel, pcr based method to identify Gpa2 homologues among Solanaceae
    Bakker, E. ; Vermaas, L. ; Vossen, E. van der; Eck, H.J. van; Klein-Lankhorst, R. ; Bakker, J. ; Rouppe van der Voort, J. - \ 2000
    In: Durable disease resistance, Key to sustainable agriculture : Durable resistance, Ede-Wageningen 2000. - Wageningen : [s.n.], 2000 - p. 72 - 72.
    A novel pcr based method to identify Gpa2 homologues among Solanaceae
    Bakker, E. ; Vermaas, L. ; Vossen, E. van der; Eck, H. van; Klein-Lankhorst, R. ; Bakker, J. ; Rouppe van der Voort, J. - \ 2000
    In: Abstract book: Interactions between plants and attacking organisms, mechanisms, genetics, ecology and evolution : Interaction between plants and attacking organisms, mechanisms, genetics, ecology and evolution, Wageningen 2000. - Wageningen : s.n.2000 - p. 20 - 20.
    Tight physical linkage of the nematode resistance gene Gpa2 and the virus resistance gene Rx on a single segment introgressed from the wild species Solanum tuberosum subsp. andigena CPC 1673 into cultivated potato
    Rouppe van der Voort, J.N.A.M. ; Kanyuka, K.A. ; Vossen, E.A.G. van der; Bendahmane, A. ; Stiekema, W.J. ; Klein Lankhorst, R. ; Baulcombe, D.C. ; Bakker, J. - \ 1999
    Molecular Plant-Microbe Interactions 12 (1999). - ISSN 0894-0282 - p. 197 - 206.
    Two Paralogous Genes of the GPA2 resistance locus confer both virus and nematode resistance to potato
    Stiekema, W.J. ; Vossen, E.A.G. van der; Sandbrink, H. ; Peters, S. ; Rouppe van der Voort, J. ; Kanyuka, K. ; Bendahmane, A. ; Bakker, J. ; Klein-Lankhorst, R.M. - \ 1999
    In: Biology of plant-microbe interactions 2 (1999) - p. 428 - 432.
    Two paralogous genes of the GPA2 resistance locus confer both virus and nematode resistance to potato
    Stiekema, W. ; Vossen, E. van der; Sandbrink, H. ; Rouppe van der Voort, J. ; Kanyuka, K. ; Bendahmane, A. ; Bakker, J. ; Klein Landhorst, R. - \ 1999
    In: Molecular Plant-microbe Interactions: book of abstracts. 9th International congress. Amsterdam July 25-30 1999. - [S.l.] : [s.n.], 1999 - p. 37 - 37.
    Linkage analysis by genotyping of sibling populations : a genetic map for the potato cyst nematode constructed using a "pseudo-F2" mapping strategy
    Rouppe van der Voort, J. ; Eck, H.J. van; Zandvoort, P.M. van; Overmars, H. ; Helder, J. ; Bakker, J. - \ 1999
    Molecular and General Genetics 261 (1999)6. - ISSN 0026-8925 - p. 1021 - 1031.
    A mapping strategy is described for the construction of a linkage map of a non-inbred species in which individual offspring genotypes are not amenable to marker analysis. After one extra generation of random mating, the segregating progeny was propagated, and bulked populations of offspring were analyzed. Although the resulting population structure is different from that of commonly used mapping populations, we show that the maximum likelihood formula for a normal F2 is applicable for the estimation of recombination. This "pseudo-F2" mapping strategy, in combination with the development of an AFLP assay for single cysts, facilitated the construction of a linkage map for the potato cyst nematode Globodera rostochiensis. Using 12 pre-selected AFLP primer combinations, a total of 66 segregating markers were identified, 62 of which were mapped to nine linkage groups. These 62 AFLP markers are randomly distributed and cover about 65% of the genome. An estimate of the physical size of the Globodera genome was obtained from comparisons of the number of AFLP fragments obtained with the values for Caenorhabditis elegans. The methodology presented here resulted in the first genomic map for a cyst nematode. The low value of the kilobase/centimorgan (kb/cM) ratio for the Globodera genome will facilitate map-based cloning of genes that mediate the interaction between the nematode and its host plant
    Development of a PCR-based selection assay for root-knot nematode resistance (Rmcl) by a comparative analysis of the solanum bulbocastanum and s. tuberorum genome
    Rouppe van der Voort, J. ; Janssen, G. ; Overmars, H. ; Zandvoort, P. van; Norel, A. van; Scholten, O. ; Janssen, R. - \ 1999
    Euphytica 106 (1999)2. - ISSN 0014-2336 - p. 187 - 195.
    A PCR-based assay has been developed for marker assisted selection of root-knot nematode resistance ( Rmc1) in potato. To this end, a comparative genome analysis was carried out between Solanum bulbocastanum and S. tuberosum to identify PCR-based chromosome 11 alleles linked to Rmc1. The use of co-migrating AFLP markers, obtained by using primer combinations previously applied for AFLP analysis of the S. tuberosum genome, failed to align the AFLP map of the S. bulbocastanum genome with the S. tuberosum map. Apparently, the S. bulbocastanum genome is genetically too distantly related to the S. tuberosum genome for this type of analysis. Cleaved amplified polymorphic sequence (CAPS) markers were more readily applied for a comparative analysis within the region of interest. Rmc1 could be localized within a 4 cM interval between markers CT182 and M39b. It is demonstrated that the resistance spectrum of Rmc1 includes not only Meloidogyne chitwoodi and the related species M. fallax but also a genetically distinct population of M. hapla. The cost-efficiency of the CAPS markers applied for Rmc1 renders this approach as an attractive alternative for screening large segregating populations of potato for root-knot nematode resistance.
    Mapping of intra-locus duplications and introgressed DNA: Aids to map-based cloning of genes from complex genomes illustrated by physical analysis of the Rx locus in tetraploid potato
    Kanyuka, K. ; Bendahmane, A. ; Rouppe van der Voort, J.N.A.M. ; Vossen, E.A.G. van der; Baulcombe, D.C. - \ 1999
    Theoretical and Applied Genetics 98 (1999). - ISSN 0040-5752 - p. 679 - 689.
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