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R. A. Pickering - One of the best experts on this subject based on the ideXlab platform.
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Erratum: Identification of all chromosome arms and their involvement in meiotic homoeologous associations at metaphase I in 2 Hordeum vulgare L. × Hordeum bulbosum L. hybrids
Genome, 2006Co-Authors: R. A. Pickering, S. Klatte, R C ButlerAbstract:We have identified all Hordeum bulbosum chromosomes in 2 diploid Hordeum vulgare × Hordeum bulbosum hybrids using suitable probes and fluorescence in situ hybridization. Using the parental idiograms allowed us to carry out a full analysis of chromosome associations among all chromosome arms in the hybrids. Association frequencies were generally lower for the short arms than for the long arms. There were also significant differences among the chromosome arms in association frequencies, partly correlated with the absolute length of the chromosome arm, as well as with the frequency of recombinant lines, which were recovered from partially fertile interspecific hybrids. The H. bulbosum idiogram will be useful for further chromosome association studies and will enable the identification of H. bulbosum chromosomes involved in chromosome addition or substitution lines.Key words: Hordeum vulgare, Hordeum bulbosum, interspecific hybrids, chromosome associations, meiosis, fluorescence in situ hybridization.
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erratum identification of all chromosome arms and their involvement in meiotic homoeologous associations at metaphase i in 2 Hordeum vulgare l Hordeum bulbosum l hybrids
Genome, 2006Co-Authors: R. A. Pickering, S. Klatte, R C ButlerAbstract:We have identified all Hordeum bulbosum chromosomes in 2 diploid Hordeum vulgare × Hordeum bulbosum hybrids using suitable probes and fluorescence in situ hybridization. Using the parental idiograms allowed us to carry out a full analysis of chromosome associations among all chromosome arms in the hybrids. Association frequencies were generally lower for the short arms than for the long arms. There were also significant differences among the chromosome arms in association frequencies, partly correlated with the absolute length of the chromosome arm, as well as with the frequency of recombinant lines, which were recovered from partially fertile interspecific hybrids. The H. bulbosum idiogram will be useful for further chromosome association studies and will enable the identification of H. bulbosum chromosomes involved in chromosome addition or substitution lines.Key words: Hordeum vulgare, Hordeum bulbosum, interspecific hybrids, chromosome associations, meiosis, fluorescence in situ hybridization.
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Mapping of Rym14Hb, a gene introgressed from Hordeum bulbosum and conferring resistance to BaMMV and BaYMV in barley.
Theoretical and Applied Genetics, 2003Co-Authors: B. Ruge, R. A. Pickering, G. Proeseler, A. Linz, P. Greif, Peter WehlingAbstract:Hordeum bulbosum represents the secondary gene pool of barley and constitutes a potential source of various disease resistances in barley breeding. Interspecific crosses of H. vulgare × H. bulbosum resulted in recombinant diploid-barley progeny with immunity to BaMMV after mechanical inoculation. Tests on fields contaminated with different viruses demonstrated that resistance was effective against all European viruses of the soil-borne virus complex (BaMMV, BaYMV-1, -2). Genetic analysis revealed that resistance was dominantly inherited. Marker analysis in a F5 mapping family was performed to map the introgression in the barley genome and to estimate its size after several rounds of recombination. RFLP anchor-marker alleles indicative of an H. bulbosum introgression were found to cover an interval 2.9 cM in length on chromosome 6HS. The soil-borne virus resistance locus harboured by this introgressed segment was designated Rym14Hb. For marker-assisted selection of Rym14Hb carriers, a diagnostic codominant STS marker was derived from an AFLP fragment amplified from leaf cDNA of homozygous-resistant genotypes inoculated with BaMMV.
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Inheritance and chromosomal location of Septoria passerinii resistance introgressed from Hordeum bulbosum into Hordeum vulgare
Plant Breeding, 2003Co-Authors: Hala Toubia-rahme, R. A. Pickering, P. A. Johnston, Brian J. Steffenson, A. GranerAbstract:Septoria speckled leaf blotch (SSLB), caused by Septoria passerinii, has become one of the most serious diseases of barley in the Upper Midwest region of the USA. The recombinant line 36L5 derived from a backcross of the susceptible barley cultivar 'Emir' and a resistant Hordeum bulbosum parent Cb2920/4/Colch was found to be resistant to S. passerinii. Two doubled haploids derived from 36L5 were backcrossed to cv. 'Emir' to obtain two BCF 2 populations for determining the inheritance of resistance to S. passerinii. BCF 2 progeny and BCF 2:3 families were evaluated at the seedling stage in the greenhouse for reaction to S. passerinii. BCF 2 progeny and BCF 2:3 families from both crosses segregated 3 : 1 (resistant : susceptible), and 1 : 2 : 1 (resistant : segregating : susceptible), respectively, indicating that the H. bulbosum-derived SSLB resistance is conferred by a single dominant gene. The H. bulbosum introgressions were positioned on chromosome 4HL by genomic and fluorescent in situ hybridizations (GISH and FISH. respectively) and by Southern hybridization with the rye repetitive sequence pSc119.2. These findings indicate that SSLB resistance in H. bulbosum has the potential to be transferred and utilized in barley breeding programs.
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PCR detection of Hordeum bulbosum introgressions in an H. vulgare background using a retrotransposon-like sequence.
Theoretical and Applied Genetics, 2002Co-Authors: P. A. Johnston, R. A. PickeringAbstract:Retrotransposon-like sequences are ideal tools for initial screening assays to distinguish between closely related species because of their ubiquitous presence, high copy number, chromosome coverage and rapid sequence evolution. A retrotransposon-like sequence, pSc119.1, cloned from Secale cereale (rye) has been used to obtain PCR primers that are capable of detecting small introgressions of Hordeum bulbosum (bulbous barley grass) chromatin in a Hordeum vulgare (cultivated barley) background. Combining this PCR-based assay with a crude but effective high-throughput DNA extraction has enabled the rapid identification of plants possessing H. bulbosum introgressions from large numbers of progeny from H. vulgare×H. bulbosum crosses. These plants are then further characterized by more-refined cytological, molecular and pathological techniques to locate and map the introgressed chromatin and to evaluate their disease resistance.
Brigitte Ruge-wehling - One of the best experts on this subject based on the ideXlab platform.
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High Resolution Mapping of a Hordeum bulbosum-Derived Powdery Mildew Resistance Locus in Barley Using Distinct Homologous Introgression Lines.
Frontiers in Plant Science, 2020Co-Authors: Parastoo Hoseinzadeh, Brigitte Ruge-wehling, Patrick Schweizer, Nils Stein, Hélène PidonAbstract:Powdery mildew caused by Blumeria graminis f. sp. hordei (Bgh) is one of the main foliar diseases in barley (Hordeum vulgare L.; Hv). Naturally occurring resistance genes used in barley breeding are a cost effective and environmentally sustainable strategy to minimize the impact of pathogens, however, the primary gene pool of H. vulgare contains limited diversity owing to recent domestication bottlenecks. To ensure durable resistance against this pathogen, more genes are required that could be unraveled by investigation of secondary barley gene-pool. A large set of Hordeum bulbosum (Hb) introgression lines (ILs) harboring a diverse set of desirable resistance traits have been developed and are being routinely used as source of novel diversity in gene mapping studies. Nevertheless, this strategy is often compromised by a lack of recombination between the introgressed fragment and the orthologous chromosome of the barley genome. In this study, we fine-mapped a Hb gene conferring resistance to barley powdery mildew. The initial genotyping of two Hb ILs mapping populations with differently sized 2HS introgressions revealed severely reduced interspecific recombination in the region of the introgressed segment, preventing precise localization of the gene. To overcome this difficulty, we developed an alternative strategy, exploiting intraspecific recombination by crossing two Hv/Hb ILs with collinear Hb introgressions, one of which carries a powdery mildew resistance gene, while the other doesn't. The intraspecific recombination rate in the Hb-introgressed fragment of 2HS was approximately 20 times higher than it was in the initial simple ILs mapping populations. Using high-throughput genotyping-by-sequencing (GBS), we allocated the resistance gene to a 1.4 Mb interval, based on an estimate using the Hv genome as reference, in populations of only 103 and 146 individuals, respectively, similar to what is expected at this locus in barley. The most likely candidate resistance gene within this interval is part of the coiled-coil nucleotide-binding-site leucine-rich-repeat (CC-NBS-LLR) gene family, which is over-represented among genes conferring strong dominant resistance to pathogens. The reported strategy can be applied as a general strategic approach for identifying genes underlying traits of interest in crop wild relatives.
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High resolution mapping of a Hordeum bulbosum-derived powdery mildew resistance locus in barley using distinct homologous introgression lines
2019Co-Authors: Parastoo Hoseinzadeh, Brigitte Ruge-wehling, Patrick Schweizer, Nils Stein, Hélène PidonAbstract:Powdery mildew caused by Blumeria graminis f.sp. hordei (Bgh) is one of the main foliar diseases in barley (Hordeum vulgare L.; Hv). Naturally occurring resistance genes used in barley breeding are a cost effective and environmentally sustainable strategy to minimize the impact of pathogens, however, the primary gene pool of H. vulgare contains limited diversity owing to recent domestication bottlenecks. To ensure durable resistance against this pathogen, more genes are required that could be unraveled by investigation of secondary barley gene-pool. A large set of Hordeum bulbosum (Hb) introgression lines (ILs) harboring a diverse set of desirable resistance traits have been developed and are being routinely used as source of novel diversity in gene mapping studies. Nevertheless, this strategy is often compromised by a lack of recombination between the introgressed fragment and the orthologous chromosome of the barley genome. In this study, we fine-mapped a Hb gene conferring resistance to barley powdery mildew. The initial genotyping of two Hb ILs mapping populations with differently sized 2HS introgressions revealed severely reduced interspecific recombination in the region of the introgressed segment, preventing precise localization of the gene. To overcome this difficulty, we developed an alternative strategy, exploiting intraspecific recombination by crossing two Hv/Hb ILs with collinear Hb introgressions, one of which carries a powdery mildew resistance gene, while the other doesn9t. The intraspecific recombination rate in the Hb-introgressed fragment of 2HS was approximately 20 times higher than it was in the initial simple ILs mapping populations. Using high-throughput genotyping-by-sequencing (GBS), we allocated the resistance gene to a 1.4 Mb interval, based on an estimate using the Hv genome as reference, in populations of only 103 and 146 individuals respectively, similar to what is expected at this locus in barley. The most likely candidate resistance gene within this interval encodes a legume-type lectin-receptor-like protein (LecRLP). Like other LecRLPs that have been implicated in resistance, this gene could be a good candidate for Hb resistance. The reported strategy can be applied as a general strategic approach for identifying genes underlying traits of interest in crop wild relatives.
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DURESTrit - mapping NHR-genes from barley secondary gene pool Hordeum bulbosum
2014Co-Authors: Behrend Von Hülsen, Brigitte Ruge-wehlingAbstract:As part of the ERA-CAPS program the DURESTrit consortium is an international collaboration between the Julius Kuhn-Institut, the Leibniz Institute of Plant Genetics and Crop Plant Research and several national and international partners. Aim is the localization and functional characterization of nonhost resistances from the primary and secondary gene pool in barley. Nonhost Resistance (NHR) is the resistance plants possess against the majority of pathogens in the environment. Therefore transferring components of NHR to crop plants from related species via introgression lines will give us new tools to protect our crops against pathogens. Our part of the project is to map new powdery mildew resistance loci for Barley, derived from the secondary gene pool Hordeum bulbosum. We use several 2HS and 2HL introgression lines differing in their H. bulbosum and Hordeum vulgare backround. All introgressions bear at least two different resistances against Blumeria graminis f. sp. hordei. For molecular characterization a mapping population will be developed. Phenotyping will be carried out by detached leaf assays with different powdery mildew isolates, checking the spectrum of resistance. Fine Mapping of the introgressions will be performed by novel marker techniques, e.g. Exome Capture and GBS. Based on the resulting sequence information CAPS, InDel, as well as SNP marker will be constructed for marker assisted selection of the novel resistance loci. Additional transcript information can be used as candidate genes getting closer to resistance loci. Recombinant plants with reduced introgression sizes will be selected with minimized introgression size and linkage drag to increase the value for breeding purposes.
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The Secondary Gene Pool of Barley (Hordeum bulbosum): Gene Introgression and Homoeologous Recombination
Biotechnological Approaches to Barley Improvement, 2014Co-Authors: Brigitte Ruge-wehling, Peter WehlingAbstract:While the primary gene pool with the two subspecies of Hordeum vulgare subsp. vulgare and H. vulgare subsp. spontaneum has long been utilised as a rich and easy-to-use gene resource for barley breeding, the secondary gene pool proved more difficult to be tapped for novel gene variants. During the past 20 years, though, ample evidence has been accumulated that the secondary gene pool of barley also presents a rich resource of trait genes which are of potential interest to breeders. To date, most disease resistances have been in the focus of interest and were introgressed from Hordeum bulbosum into barley, among them resistances to a variety of pathogenic fungi as well as viruses. The use of molecular techniques such as in situ hybridisation and molecular markers has provided a deeper insight into the chromosomal locations of introgressed segments, their sizes and recombination activities against a barley-genetic background and has paved the way for a deliberate selection of recombinant offspring which can be used in plant breeding programmes. Thus, it can be stated that the secondary gene pool of barley has been opened up as a novel genetic resource in barley breeding.
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Ryd4 Hb : a novel resistance gene introgressed from Hordeum bulbosum into barley and conferring complete and dominant resistance to the barley yellow dwarf virus
Theoretical and Applied Genetics, 2009Co-Authors: Margret Scholz, Brigitte Ruge-wehling, Antje Habekuß, Otto Schrader, Galina Pendinen, Kristin Fischer, Peter WehlingAbstract:Barley yellow dwarf virus (BYDV) causes high yield losses in most of the major cereal crops worldwide. A source of very effective resistance was detected within the tetraploid wild species of Hordeum bulbosum. Interspecific crosses between a resistant H. bulbosum accession and H. vulgare cv. ‘Igri’ were performed to transfer this resistance into cultivated barley. Backcrosses to H. vulgare resulted in offspring which carried a single subterminal introgression of H. bulbosum chromatin on barley chromosome 3HL and proved to be fully resistant to BYDV-PAV, as inferred by ELISA values of zero or close to zero and lack of BYDV symptoms. Genetic analysis indicated a dominant inheritance of the BYDV-PAV resistance factor, which we propose to denote Ryd4 Hb . The identity and effect of Ryd4 Hb are discussed in relation to other known genes for BYDV resistance or tolerance, as well as the relevance of this gene for resistance breeding in barley.
Peter Wehling - One of the best experts on this subject based on the ideXlab platform.
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The Secondary Gene Pool of Barley (Hordeum bulbosum): Gene Introgression and Homoeologous Recombination
Biotechnological Approaches to Barley Improvement, 2014Co-Authors: Brigitte Ruge-wehling, Peter WehlingAbstract:While the primary gene pool with the two subspecies of Hordeum vulgare subsp. vulgare and H. vulgare subsp. spontaneum has long been utilised as a rich and easy-to-use gene resource for barley breeding, the secondary gene pool proved more difficult to be tapped for novel gene variants. During the past 20 years, though, ample evidence has been accumulated that the secondary gene pool of barley also presents a rich resource of trait genes which are of potential interest to breeders. To date, most disease resistances have been in the focus of interest and were introgressed from Hordeum bulbosum into barley, among them resistances to a variety of pathogenic fungi as well as viruses. The use of molecular techniques such as in situ hybridisation and molecular markers has provided a deeper insight into the chromosomal locations of introgressed segments, their sizes and recombination activities against a barley-genetic background and has paved the way for a deliberate selection of recombinant offspring which can be used in plant breeding programmes. Thus, it can be stated that the secondary gene pool of barley has been opened up as a novel genetic resource in barley breeding.
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Ryd4 Hb : a novel resistance gene introgressed from Hordeum bulbosum into barley and conferring complete and dominant resistance to the barley yellow dwarf virus
Theoretical and Applied Genetics, 2009Co-Authors: Margret Scholz, Brigitte Ruge-wehling, Antje Habekuß, Otto Schrader, Galina Pendinen, Kristin Fischer, Peter WehlingAbstract:Barley yellow dwarf virus (BYDV) causes high yield losses in most of the major cereal crops worldwide. A source of very effective resistance was detected within the tetraploid wild species of Hordeum bulbosum. Interspecific crosses between a resistant H. bulbosum accession and H. vulgare cv. ‘Igri’ were performed to transfer this resistance into cultivated barley. Backcrosses to H. vulgare resulted in offspring which carried a single subterminal introgression of H. bulbosum chromatin on barley chromosome 3HL and proved to be fully resistant to BYDV-PAV, as inferred by ELISA values of zero or close to zero and lack of BYDV symptoms. Genetic analysis indicated a dominant inheritance of the BYDV-PAV resistance factor, which we propose to denote Ryd4 Hb . The identity and effect of Ryd4 Hb are discussed in relation to other known genes for BYDV resistance or tolerance, as well as the relevance of this gene for resistance breeding in barley.
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Mapping of Rym14Hb, a gene introgressed from Hordeum bulbosum and conferring resistance to BaMMV and BaYMV in barley.
Theoretical and Applied Genetics, 2003Co-Authors: B. Ruge, R. A. Pickering, G. Proeseler, A. Linz, P. Greif, Peter WehlingAbstract:Hordeum bulbosum represents the secondary gene pool of barley and constitutes a potential source of various disease resistances in barley breeding. Interspecific crosses of H. vulgare × H. bulbosum resulted in recombinant diploid-barley progeny with immunity to BaMMV after mechanical inoculation. Tests on fields contaminated with different viruses demonstrated that resistance was effective against all European viruses of the soil-borne virus complex (BaMMV, BaYMV-1, -2). Genetic analysis revealed that resistance was dominantly inherited. Marker analysis in a F5 mapping family was performed to map the introgression in the barley genome and to estimate its size after several rounds of recombination. RFLP anchor-marker alleles indicative of an H. bulbosum introgression were found to cover an interval 2.9 cM in length on chromosome 6HS. The soil-borne virus resistance locus harboured by this introgressed segment was designated Rym14Hb. For marker-assisted selection of Rym14Hb carriers, a diagnostic codominant STS marker was derived from an AFLP fragment amplified from leaf cDNA of homozygous-resistant genotypes inoculated with BaMMV.
Richard Pickering - One of the best experts on this subject based on the ideXlab platform.
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Rph22: mapping of a novel leaf rust resistance gene introgressed from the non-host Hordeum bulbosum L. into cultivated barley (Hordeum vulgare L.)
Theoretical and Applied Genetics, 2013Co-Authors: Paul A. Johnston, Rients E. Niks, Vijitha Meiyalaghan, Elise Blanchet, Richard PickeringAbstract:A resistance gene (Rph22) to barley leaf rust caused by Puccinia hordei was introgressed from the non-host species Hordeum bulbosum into cultivated barley. The H. bulbosum introgression in line ‘182Q20’ was located to chromosome 2HL using genomic in situ hybridisation (GISH). Using molecular markers it was shown to cover approximately 20 % of the genetic length of the chromosome. The introgression confers a very high level of resistance to P. hordei at the seedling stage that is not based on a hypersensitive reaction. The presence of the resistance gene increased the latency period of the leaf rust fungus and strongly reduced the infection frequency relative to the genetic background cultivar ‘Golden Promise’. An F2 population of 550 individuals was developed and used to create a genetic map of the introgressed region and to determine the map position of the underlying resistance gene(s). The resistance locus, designated Rph22, was located to the distal portion of the introgression, co-segregating with markers H35_26334 and H35_45139. Flanking markers will be used to reduce the linkage drag, including gene(s) responsible for a yield penalty, around the resistance locus and to transfer the gene into elite barley germplasm. This genetic location is also known to harbour a QTL (Rphq2) for non-hypersensitive leaf rust resistance in the barley cultivar ‘Vada’. Comparison of the ‘Vada’ and H. bulbosum resistances at this locus may lead to a better understanding of the possible association between host and non-host resistance mechanisms.
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Marker development and characterisation of Hordeum bulbosum introgression lines: a resource for barley improvement
Theoretical and Applied Genetics, 2009Co-Authors: Paul A. Johnston, Gail M. Timmerman-vaughan, Kevin J. F. Farnden, Richard PickeringAbstract:A set of 110 diploid putative introgression lines (ILs) containing chromatin introgressed from the undomesticated species Hordeum bulbosum L. (bulbous barley grass) into cultivated barley ( Hordeum vulgare L.) has been identified using a high-copy number retrotransposon-like PCR marker, pSc119.1, derived from rye ( Secale cereale L.). To evaluate these lines, 92 EST-derived markers were developed by marker sequencing across four barley cultivars and four H. bulbosum genotypes. Single nucleotide polymorphisms and insertions/deletions conserved between the two species were then used to develop a set of fully informative cleaved amplified polymorphic sequence markers or size polymorphic insertion/deletion markers. Introgressed chromatin from H. bulbosum was confirmed and genetically located in 88 of these lines using 46 of the EST-derived PCR markers. A total of 96 individual introgressions were detected with most of them (94.8%) extending to the most distal marker for each respective chromosome arm. Introgressions were detected on all chromosome arms except chromosome 3HL. Interstitial or sub-distal introgressions also occurred, with two located on chromosome 2HL and one each on 3HS, 5HL and 6HS. Twenty-two putative ILs that were positive for H. bulbosum chromatin using pSc119.1 have not had introgressions detected with these single-locus markers. When all introgressions are combined, more than 36% of the barley genetic map has now been covered with introgressed chromatin from H. bulbosum . These ILs represent a significant germplasm resource for barley improvement that can be mined for diverse traits of interest to barley breeders and researchers.
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Hordeum vulgare h bulbosum tetraploid hybrid provides useful agronomic introgression lines for breeders
New Zealand Journal of Crop and Horticultural Science, 2001Co-Authors: Liangtao Zhang, Richard Pickering, Brian G. MurrayAbstract:Abstract A sterile hybrid between barley and Hordeum bulbosum L. that showed regular chromosome pairing at meiotic metaphase was treated with colchicine to induce polyploidy to restore fertility. Selfed diploid progenies of this hybrid were screened for resistance to leaf rust and powdery mildew and the presence of other H. bulbosum‐like, characters. A combination of fluorescent in situ hybridisation (FISH) and genomic in situ hybridisation (GISH) was used to identify and characterise introgressed chromosome segments of H. bulbosum chromatin and to locate them to specific barley chromosomes. The size of introgression segments varied considerably between different plants. This material provides valuable new germplasm for breeding disease resistant barley.
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Hordeum vulgare × H. bulbosum tetraploid hybrid provides useful agronomic introgression lines for breeders
New Zealand Journal of Crop and Horticultural Science, 2001Co-Authors: Liangtao Zhang, Richard Pickering, Brian G. MurrayAbstract:Abstract A sterile hybrid between barley and Hordeum bulbosum L. that showed regular chromosome pairing at meiotic metaphase was treated with colchicine to induce polyploidy to restore fertility. Selfed diploid progenies of this hybrid were screened for resistance to leaf rust and powdery mildew and the presence of other H. bulbosum‐like, characters. A combination of fluorescent in situ hybridisation (FISH) and genomic in situ hybridisation (GISH) was used to identify and characterise introgressed chromosome segments of H. bulbosum chromatin and to locate them to specific barley chromosomes. The size of introgression segments varied considerably between different plants. This material provides valuable new germplasm for breeding disease resistant barley.
B. Ruge - One of the best experts on this subject based on the ideXlab platform.
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Importance of the Secondary Genepool in Barley Genetics and Breeding. I. Cytogenetics and Molecular Analysis
Czech Journal of Genetics and Plant Breeding, 2011Co-Authors: R. Pickering, A. Johnston P, B. RugeAbstract:There have been no plant breeding developments using species from the tertiary genepool of cultivated barley for breeding or genetics since the VIII<sup>th</sup> International Barley Genetics Symposium in 2000. Hence, the first part of this review describes progress since 2000 in developing and characterising recombinant lines derived from hybridisations between the sole species in the secondary genepool, Hordeum bulbosum L., and cultivated barley, Hordeum vulgare L. The topics discussed in part I are cytogenetics and molecular analysis of recombinant lines.
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Mapping of Rym14 ^ Hb , a gene introgressed from Hordeum bulbosum and conferring resistance to BaMMV and BaYMV in barley
Theoretical and Applied Genetics, 2003Co-Authors: B. Ruge, G. Proeseler, A. Linz, P. Greif, R. Pickering, P. WehlingAbstract:Hordeum bulbosum represents the secondary gene pool of barley and constitutes a potential source of various disease resistances in barley breeding. Interspecific crosses of H. vulgare × H. bulbosum resulted in recombinant diploid-barley progeny with immunity to BaMMV after mechanical inoculation. Tests on fields contaminated with different viruses demonstrated that resistance was effective against all European viruses of the soil-borne virus complex (BaMMV, BaYMV-1, -2). Genetic analysis revealed that resistance was dominantly inherited. Marker analysis in a F5 mapping family was performed to map the introgression in the barley genome and to estimate its size after several rounds of recombination. RFLP anchor-marker alleles indicative of an H. bulbosum introgression were found to cover an interval 2.9 cM in length on chromosome 6HS. The soil-borne virus resistance locus harboured by this introgressed segment was designated Rym14 ^ Hb . For marker-assisted selection of Rym14 ^ Hb carriers, a diagnostic codominant STS marker was derived from an AFLP fragment amplified from leaf cDNA of homozygous-resistant genotypes inoculated with BaMMV.
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Mapping of Rym14Hb, a gene introgressed from Hordeum bulbosum and conferring resistance to BaMMV and BaYMV in barley.
Theoretical and Applied Genetics, 2003Co-Authors: B. Ruge, R. A. Pickering, G. Proeseler, A. Linz, P. Greif, Peter WehlingAbstract:Hordeum bulbosum represents the secondary gene pool of barley and constitutes a potential source of various disease resistances in barley breeding. Interspecific crosses of H. vulgare × H. bulbosum resulted in recombinant diploid-barley progeny with immunity to BaMMV after mechanical inoculation. Tests on fields contaminated with different viruses demonstrated that resistance was effective against all European viruses of the soil-borne virus complex (BaMMV, BaYMV-1, -2). Genetic analysis revealed that resistance was dominantly inherited. Marker analysis in a F5 mapping family was performed to map the introgression in the barley genome and to estimate its size after several rounds of recombination. RFLP anchor-marker alleles indicative of an H. bulbosum introgression were found to cover an interval 2.9 cM in length on chromosome 6HS. The soil-borne virus resistance locus harboured by this introgressed segment was designated Rym14Hb. For marker-assisted selection of Rym14Hb carriers, a diagnostic codominant STS marker was derived from an AFLP fragment amplified from leaf cDNA of homozygous-resistant genotypes inoculated with BaMMV.