T. Pfaff - Academia.edu (original) (raw)

Papers by T. Pfaff

Research paper thumbnail of Mapping of gene-specific markers on the genetic map of chickpea ( Cicer arietinum L.)

Molecular Genetics and Genomics, 2003

With the exception of the fact that it is made up of eight different chromosomes, the physical or... more With the exception of the fact that it is made up of eight different chromosomes, the physical organization of the 738-Mb genome of the important legume crop chickpea (Cicer arietinum L.) is unknown. In an attempt to increase our knowledge of the basic structure of this genome, we determined the map positions of a series of genes involved in plant defence responses (DR) by genetic linkage analysis. Exploiting the sequence data available in GenBank, we selected genes known to be induced in chickpea and other plants by pathogen attack. Gene-specific primers were designed based on conserved regions, and used to detect the corresponding gene sequences in a segregating population derived from an interspecific cross between Cicer arietinum and C. reticulatum. Forty-seven gene-specific markers were integrated into an existing map based on STMS, AFLP, DAF and other anonymous markers. The potential of this approach is discussed.

Research paper thumbnail of DAF marker tightly linked to a major locus for Ascochyta blight resistance in chickpea ( Cicer arietinum L .)

Euphytica, 2003

Resistance of chickpea against the disease caused by the ascomycete Ascochyta rabiei is encoded b... more Resistance of chickpea against the disease caused by the ascomycete Ascochyta rabiei is encoded by two or three quantitative trait loci, QTL1, QTL2 and QTL3. A total of 94 recombinant inbred lines developed from a wide cross between a resistant chickpea line and a susceptible accession of Cicer reticulatum, a close relative of cultivated chickpea, was used to identify markers

Research paper thumbnail of A linkage map of the chickpea (Cicer arietinum L.) genome based on recombinant inbred lines from a C. arietinum×C. reticulatum cross: localization of resistance genes for fusarium wilt races 4 and 5

Theoretical and Applied Genetics, 2000

An integrated molecular marker map of the chickpea genome was established using 130 recombinant i... more An integrated molecular marker map of the chickpea genome was established using 130 recombinant inbred lines from a wide cross between a cultivar resistant to fusarium wilt caused by Fusarium oxysporum Schlecht. emend. Snyd. &. Hans f. sp. ciceri (Padwick) Snyd & Hans, and an accession of Cicer reticulatum (PI 489777), the wild progenitor of chickpea. A total of 354 markers were mapped on the RILs including 118 STMSs, 96 DAFs, 70 AFLPs, 37 ISSRs, 17 RAPDs, eight isozymes, three cDNAs, two SCARs and three loci that confer resistance against different races of fusarium wilt. At a LOD-score of 4.0, 303 markers cover 2077.9 cM in eight large and eight small linkage groups at an average distance of 6.8 cM between markers. Fifty one markers (14.4%) were unlinked. A clustering of markers in central regions of linkage groups was observed. Markers of the same class, except for ISSR and RAPD markers, tended to generate subclusters. Also, genes for resistance to races 4 and 5 of fusarium wilt map to the same linkage group that includes an STMS and a SCAR marker previously shown to be linked to fusarium wilt race 1, indicating a clustering of several fusarium-wilt resistance genes around this locus. Significant deviation from the expected 1 : 1 segregation ratio was observed for 136 markers (38.4%, P<0.05). Segregation was biased towards the wild progenitor in 68% of the cases. Segregation distortion was similar for all marker types except for ISSRs that showed only 28.5% aberrant segregation. The map is the most extended genetic map of chickpea currently available. It may serve as a basis for markerassisted selection and map-based cloning of fusarium wilt resistance genes and other agronomically important genes in future.

Research paper thumbnail of Characterization and mapping of sequence-tagged microsatellite sites in the chickpea (Cicer arietinum L.) genome

Molecular and General Genetics MGG, 1999

A size-selected genomic library comprising 280,000 colonies and representing approximately 18% of... more A size-selected genomic library comprising 280,000 colonies and representing approximately 18% of the chickpea genome, was screened for (GA)n, (GAA)n and (TAA)n microsatellite-containing clones, of which 389 were sequenced. The majority (approximately 75%) contained perfect repeats; interrupted, interrupted compound and compound repeats were only present in 6%-9% of cases. (TAA)-microsatellites contained the longest repeats, with unit numbers from 9 to 131. For 218 loci primers could be designed and used for the detection of microsatellite length polymorphisms in six chickpea breeding cultivars, as well as in C. reticulatum and C. echinospermum, wild, intercrossable relatives of chickpea. A total of 174 primer pairs gave interpretable banding patterns, 137 (79%) of which revealed at least two alleles on native polyacrylamide gels. A total of 120 sequence-tagged microsatellite site (STMS) markers were genetically mapped in 90 recombinant inbred lines from an inter-species cross between C. reticulatum and the chickpea cultivar ICC 4958. Markers could be arranged in 11 linkage groups (at a LOD score of 4) covering 613 cM. Clustering as well as random distribution of loci was observed. Segregation of 46 markers (39%) deviated significantly (P &amp;amp;gt; or = 0.05) from the expected 1:1 ratio. The majority of these loci (73%) were located in three distinct regions of the genome. The present STMS marker map represents the most advanced co-dominant DNA marker map of the chickpea genome.

Research paper thumbnail of Mapping of gene-specific markers on the genetic map of chickpea ( Cicer arietinum L.)

Molecular Genetics and Genomics, 2003

With the exception of the fact that it is made up of eight different chromosomes, the physical or... more With the exception of the fact that it is made up of eight different chromosomes, the physical organization of the 738-Mb genome of the important legume crop chickpea (Cicer arietinum L.) is unknown. In an attempt to increase our knowledge of the basic structure of this genome, we determined the map positions of a series of genes involved in plant defence responses (DR) by genetic linkage analysis. Exploiting the sequence data available in GenBank, we selected genes known to be induced in chickpea and other plants by pathogen attack. Gene-specific primers were designed based on conserved regions, and used to detect the corresponding gene sequences in a segregating population derived from an interspecific cross between Cicer arietinum and C. reticulatum. Forty-seven gene-specific markers were integrated into an existing map based on STMS, AFLP, DAF and other anonymous markers. The potential of this approach is discussed.

Research paper thumbnail of DAF marker tightly linked to a major locus for Ascochyta blight resistance in chickpea ( Cicer arietinum L .)

Euphytica, 2003

Resistance of chickpea against the disease caused by the ascomycete Ascochyta rabiei is encoded b... more Resistance of chickpea against the disease caused by the ascomycete Ascochyta rabiei is encoded by two or three quantitative trait loci, QTL1, QTL2 and QTL3. A total of 94 recombinant inbred lines developed from a wide cross between a resistant chickpea line and a susceptible accession of Cicer reticulatum, a close relative of cultivated chickpea, was used to identify markers

Research paper thumbnail of A linkage map of the chickpea (Cicer arietinum L.) genome based on recombinant inbred lines from a C. arietinum×C. reticulatum cross: localization of resistance genes for fusarium wilt races 4 and 5

Theoretical and Applied Genetics, 2000

An integrated molecular marker map of the chickpea genome was established using 130 recombinant i... more An integrated molecular marker map of the chickpea genome was established using 130 recombinant inbred lines from a wide cross between a cultivar resistant to fusarium wilt caused by Fusarium oxysporum Schlecht. emend. Snyd. &. Hans f. sp. ciceri (Padwick) Snyd & Hans, and an accession of Cicer reticulatum (PI 489777), the wild progenitor of chickpea. A total of 354 markers were mapped on the RILs including 118 STMSs, 96 DAFs, 70 AFLPs, 37 ISSRs, 17 RAPDs, eight isozymes, three cDNAs, two SCARs and three loci that confer resistance against different races of fusarium wilt. At a LOD-score of 4.0, 303 markers cover 2077.9 cM in eight large and eight small linkage groups at an average distance of 6.8 cM between markers. Fifty one markers (14.4%) were unlinked. A clustering of markers in central regions of linkage groups was observed. Markers of the same class, except for ISSR and RAPD markers, tended to generate subclusters. Also, genes for resistance to races 4 and 5 of fusarium wilt map to the same linkage group that includes an STMS and a SCAR marker previously shown to be linked to fusarium wilt race 1, indicating a clustering of several fusarium-wilt resistance genes around this locus. Significant deviation from the expected 1 : 1 segregation ratio was observed for 136 markers (38.4%, P<0.05). Segregation was biased towards the wild progenitor in 68% of the cases. Segregation distortion was similar for all marker types except for ISSRs that showed only 28.5% aberrant segregation. The map is the most extended genetic map of chickpea currently available. It may serve as a basis for markerassisted selection and map-based cloning of fusarium wilt resistance genes and other agronomically important genes in future.

Research paper thumbnail of Characterization and mapping of sequence-tagged microsatellite sites in the chickpea (Cicer arietinum L.) genome

Molecular and General Genetics MGG, 1999

A size-selected genomic library comprising 280,000 colonies and representing approximately 18% of... more A size-selected genomic library comprising 280,000 colonies and representing approximately 18% of the chickpea genome, was screened for (GA)n, (GAA)n and (TAA)n microsatellite-containing clones, of which 389 were sequenced. The majority (approximately 75%) contained perfect repeats; interrupted, interrupted compound and compound repeats were only present in 6%-9% of cases. (TAA)-microsatellites contained the longest repeats, with unit numbers from 9 to 131. For 218 loci primers could be designed and used for the detection of microsatellite length polymorphisms in six chickpea breeding cultivars, as well as in C. reticulatum and C. echinospermum, wild, intercrossable relatives of chickpea. A total of 174 primer pairs gave interpretable banding patterns, 137 (79%) of which revealed at least two alleles on native polyacrylamide gels. A total of 120 sequence-tagged microsatellite site (STMS) markers were genetically mapped in 90 recombinant inbred lines from an inter-species cross between C. reticulatum and the chickpea cultivar ICC 4958. Markers could be arranged in 11 linkage groups (at a LOD score of 4) covering 613 cM. Clustering as well as random distribution of loci was observed. Segregation of 46 markers (39%) deviated significantly (P &amp;amp;gt; or = 0.05) from the expected 1:1 ratio. The majority of these loci (73%) were located in three distinct regions of the genome. The present STMS marker map represents the most advanced co-dominant DNA marker map of the chickpea genome.