28 results on '"Szabo-Hever A"'
Search Results
2. Association mapping of resistance to tan spot in the Global Durum Panel
- Author
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Agnes Szabo-Hever, Gurminder Singh, Amanda Peters Haugrud, Katherine Running, Sudeshi Seneviratne, Zengcui Zhang, Gongjun Shi, Filippo Bassi, Marco Maccaferri, Luigi Cattivelli, Roberto Tuberosa, Timothy L. Friesen, Zhaohui Liu, Steven S. Xu, and Justin D. Faris
- Subjects
Plant Science ,Agronomy and Crop Science - Abstract
Tan spot, caused by the necrotrophic fungal pathogen Pyrenophora tritici-repentis (Ptr), is an important disease of durum and common wheat worldwide. Compared to common wheat, less is known about the genetics and molecular basis of tan spot resistance in durum wheat. We evaluated 510 durum lines from the Global Durum wheat Panel (GDP) for sensitivity to the necrotrophic effectors (NEs) Ptr ToxA and Ptr ToxB, and for reaction to Ptr isolates representing races 1–5. Overall, susceptible durum lines were most prevalent in South Asia, the Middle East, and North Africa. Genome-wide association analysis showed the resistance locus Tsr7 was significantly associated with tan spot caused by races 2 and 3, but not races 1, 4, or 5. The NE sensitivity genes Tsc1 and Tsc2 were associated with susceptibility to Ptr ToxC- and Ptr ToxB-producing isolates, respectively, but Tsn1 was not associated with tan spot caused by Ptr ToxA-producing isolates, which further validates that the Tsn1-Ptr ToxA interaction does not play a significant role in tan spot development in durum. A unique locus on chromosome arm 2AS was associated with tan spot caused by race 4, a race once considered avirulent. A novel trait characterized by expanding chlorosis leading to increased disease severity caused by the Ptr ToxB-producing race 5 isolate DW5 was identified, and this trait was governed by a locus on chromosome 5B. We recommend that durum breeders select resistance alleles at the Tsr7, Tsc1, Tsc2, and the chromosome 2AS loci to obtain broad resistance to tan spot.
- Published
- 2023
3. Genetic Diversity and Resistance to Fusarium Head Blight in Synthetic Hexaploid Wheat Derived From Aegilops tauschii and Diverse Triticum turgidum Subspecies
- Author
-
Agnes Szabo-Hever, Qijun Zhang, Timothy L. Friesen, Shaobin Zhong, Elias M. Elias, Xiwen Cai, Yue Jin, Justin D. Faris, Shiaoman Chao, and Steven S. Xu
- Subjects
wheat ,synthetic hexaploid wheat ,Aegilops tauschii ,tetraploid wheat ,Triticum turgidum ,Fusarium head blight ,Plant culture ,SB1-1110 - Abstract
Synthetic hexaploid wheat (SHW) can serve as a bridge for the transfer of useful genes from Aegilops tauschii and tetraploid wheat (Triticum turgidum) into common wheat (T. aestivum). The objective of this study was to evaluate 149 SHW lines and their 74 tetraploid parents for their genetic diversity, breeding values and inter-genomic interactions for resistance to Fusarium head blight (FHB). The genetic diversity analysis was performed based on the population structure established using 4,674 and 3,330 polymorphic SNP markers among the SHW lines and tetraploid parents, respectively. The results showed that all T. carthlicum and most T. dicoccum accessions formed different clusters and subpopulations, respectively, whereas all the T. durum, T. polonicum, T. turgidum, and T. turanicum accessions were clustered together, suggesting that T. durum was more closely related to T. polonicum, T. turgidum, and T. turanicum than to T. dicoccum. The genetic diversity of the SHW lines mainly reflected that of the tetraploid parents. The SHW lines and their tetraploid parents were evaluated for reactions to FHB in two greenhouse seasons and at two field nurseries for 2 years. As expected, most of the SHW lines were more resistant than their tetraploid parents in all environments. The FHB severities of the SHW lines varied greatly depending on the Ae. tauschii and tetraploid genotypes involved. Most of the SHW lines with a high level of FHB resistance were generally derived from the tetraploid accessions with a high level of FHB resistance. Among the 149 SHW lines, 140 were developed by using three Ae. tauschii accessions CIae 26, PI 268210, and RL 5286. These SHW lines showed FHB severities reduced by 21.7%, 17.3%, and 11.5%, respectively, with an average reduction of 18.3%, as compared to the tetraploid parents, suggesting that the D genome may play a major role in reducing disease severity in the SHW lines. Thirteen SHW lines consistently showed a high level of FHB resistance compared to the resistant check, Sumai 3, in each environment. These SHW lines will be useful for the development of FHB-resistant wheat germplasm and populations for discovery of novel FHB resistance genes.
- Published
- 2018
- Full Text
- View/download PDF
4. Genome-wide association mapping of resistance to the foliar diseases septoria nodorum blotch and tan spot in a global winter wheat collection
- Author
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Amanda R. Peters Haugrud, Gongjun Shi, Sudeshi Seneviratne, Katherine L.D. Running, Zengcui Zhang, Gurminder Singh, Agnes Szabo-Hever, Krishna Acharya, Timothy L. Friesen, Zhaohui Liu, and Justin D. Faris
- Abstract
Septoria nodorum blotch (SNB) and tan spot, caused by the necrotrophic fungal pathogens Parastagonospora nodorum and Pyrenophora tritici-repentis, respectively, often occur together as a leaf spotting disease complex on wheat (Triticum aestivum L.). Both pathogens produce necrotrophic effectors (NEs) that contribute to the development of disease. Here, genome-wide association analysis of a diverse panel of 264 winter wheat lines revealed novel loci on chromosomes 5A and 5B associated with sensitivity to the NEs SnTox3 and SnTox5 in addition to the known sensitivity genes for NEs Ptr/SnToxA, SnTox1, SnTox3, and SnTox5. Sensitivity loci for SnTox267 and Ptr ToxB were not detected. Evaluation of the panel with five P. nodorum isolates for SNB development indicated the Snn3-SnTox3 and Tsn1-SnToxA interactions played significant roles in disease development along with additional QTL on chromosomes 2A and 2D, which may correspond to the Snn7-SnTox267 interaction. For tan spot, the Tsc1-Ptr ToxC interaction was associated with disease caused by two isolates, and a novel QTL on chromosome 7D was associated with a third isolate. The Tsn1-ToxA interaction was associated with SNB but not tan spot. Therefore some, but not all, of the previously characterized host gene-NE interactions in these pathosystems play significant roles in disease development in winter wheat. Based on these results, breeders should prioritize the selection of resistance alleles at the Tsc1, Tsn1, Snn3, and Snn7 loci as well as the 2A and 7D QTL to obtain good levels of resistance to SNB and tan spot in winter wheat.
- Published
- 2023
5. Association Mapping of Resistance to Tan Spot in the Global Durum Panel.
- Author
-
Szabo-Hever, Agnes, Singh, Gurminder, Haugrud, Amanda R. Peters, Running, Katherine L. D., Seneviratne, Sudeshi, Zengcui Zhang, Gongjun Shi, Bassi, Filippo M., Maccaferri, Marco, Cattivelli, Luigi, Tuberosa, Roberto, Friesen, Timothy L., Zhaohui Liu, Xu, Steven S., and Faris, Justin D.
- Subjects
- *
DURUM wheat , *RACE , *MOLECULAR genetics , *GENOME-wide association studies , *CHROMOSOMES , *PYRENOPHORA - Abstract
Tan spot, caused by the necrotrophic fungal pathogen Pyrenophora tritici-repentis (Ptr), is an important disease of durum and common wheat worldwide. Compared with common wheat, less is known about the genetics and molecular basis of tan spot resistance in durum wheat. We evaluated 510 durum lines from the Global Durum Wheat Panel (GDP) for sensitivity to the necrotrophic effectors (NEs) Ptr ToxA and Ptr ToxB and for reaction to Ptr isolates representing races 1 to 5. Overall, susceptible durum lines were most prevalent in South Asia, the Middle East, and North Africa. Genome-wide association analysis showed that the resistance locus Tsr7 was significantly associated with tan spot caused by races 2 and 3, but not races 1,4, or 5. The NE sensitivity genes Tscl and Tsc2 were associated with susceptibility to Ptr ToxC- and Ptr ToxB-producing isolates, respectively, but Tsnl was not associated with tan spot caused by Ptr ToxA-producing isolates, which further validates that the Tsnl--Ptr ToxA interaction does not play a significant role in tan spot development in durum. A unique locus on chromosome arm 2AS was associated with tan spot caused by race 4, a race once considered avirulent. A novel trait characterized by expanding chlorosis leading to increased disease severity caused by the Ptr ToxB-producing race 5 isolate DW5 was identified, and this trait was governed by a locus on chromosome 5B. We recommend that durum breeders select resistance alleles at the Tsr7, Tscl, Tsc2, and the chromosome 2AS loci to obtain broad resistance to tan spot. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
6. Evaluation of Genetic Diversity and Host Resistance to Stem Rust in USDA NSGC Durum Wheat Accessions
- Author
-
Shiaoman Chao, Matthew N. Rouse, Maricelis Acevedo, Agnes Szabo-Hever, Harold Bockelman, J. Michael Bonman, Elias Elias, Daryl Klindworth, and Steven Xu
- Subjects
Plant culture ,SB1-1110 ,Genetics ,QH426-470 - Abstract
The USDA–ARS National Small Grains Collection (NSGC) maintains germplasm representing global diversity of small grains and their wild relatives. To evaluate the utility of the NSGC durum wheat ( L. ssp. ) accessions, we assessed genetic diversity and linkage disequilibrium (LD) patterns in a durum core subset containing 429 lines with spring growth habit originating from 64 countries worldwide. Genetic diversity estimated using wheat single-nucleotide polymorphism (SNP) markers showed considerable diversity captured in this collection. Average LD decayed over a genetic distance to within 3 cM at = 0.2, with a fast LD decay for markers linked at >5 cM. We evaluated accessions for resistance to wheat stem rust, caused by a fungal pathogen, Pers. Pers. f. sp. Eriks. and E. Henn (), using races from both eastern Africa and North America, at seedling and adult plant stages. Five accessions were identified as resistant to all stem rust pathogen races evaluated. Genome-wide association analysis detected 17 significant associations at the seedling stage with nine likely corresponding to , , and and the remaining potentially being novel genes located on six chromosomes. A higher frequency of resistant accessions was found at the adult plant stage than at the seedling stage. However, few significant associations were detected possibly a result of strong G × E interactions not properly accounted for in the mixed model. Nonetheless, the resistant accessions identified in this study should provide wheat breeders with valuable resources for improving stem rust resistance.
- Published
- 2017
- Full Text
- View/download PDF
7. Alternaria hungarica sp. nov., a minor foliar pathogen of wheat in Hungary
- Author
-
Tóth, Beáta, Csõsz, Mária, Szabó-Hevér, Ágnes, Simmons, Emory G., Samson, Robert A., and Varga, János
- Published
- 2011
8. MAPPING OF FHB RESISTANCE QTLS IN THE MINI MANO/FRONTANA AND FRONTANA/REMUS DH POPULATIONS
- Author
-
SZABÓ-HEVÉR, Ágnes, TÓTH, Beáta, LEHOCZKI-KRSJAK, Szabolcs, and MESTERHÁZY, Ákos
- Published
- 2008
9. CHEMICAL CONTROL OF FHB IN WHEAT WITH DIFFERENT NOZZLE TYPES AND FUNGICIDES
- Author
-
LECHOCZKI-KRSJAK, Szabolcs, TÓTH, Beáta, KÓTAI, Csaba, MARTONOSI, Imre, FARÁDY, LÁSZLÓ, KONDRÁK, László, SZABÓ-HEVÉR, Ágnes, and MESTERHÁZY, Ákos
- Published
- 2008
10. REPRODUCTIVE MODE OF CENTRAL EUROPEAN FUSARIUM GRAMINEARUM AND F. CULMORUM POPULATIONS
- Author
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TÓTH, Beáta, VARGA, János, SZABÓ-HEVÉR, Ágnes, LEHOCZKIKRSJAK, Szabolcs, and MESTERHÁZY, Ákos
- Published
- 2008
11. Node Infection Caused by Fusarium graminearum in Wheat
- Author
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Mesterházy, Á., Tóth, B., Szabó-Hevér, Á., Varga, J., and Lehoczki-Krsjak, S.
- Published
- 2008
12. A protein kinase-major sperm protein gene hijacked by a necrotrophic fungal pathogen triggers disease susceptibility in wheat
- Author
-
Gongjun Shi, Agnes Szabo‐Hever, Amanda R. Peters Haugrud, Zengcui Zhang, Sudeshi Seneviratne, Katherine L. D. Running, Robert Brueggeman, Justin D. Faris, Steven S. Xu, and Timothy L. Friesen
- Subjects
0106 biological sciences ,0301 basic medicine ,Aegilops ,Plant Science ,Plant disease resistance ,Genes, Plant ,01 natural sciences ,03 medical and health sciences ,Pathosystem ,Septoria ,Ascomycota ,Genetics ,Aegilops tauschii ,Common wheat ,Gene ,Phylogeny ,Triticum ,Plant Diseases ,Plant Proteins ,biology ,Effector ,food and beverages ,Cell Biology ,biology.organism_classification ,Major sperm protein ,030104 developmental biology ,Host-Pathogen Interactions ,Pollen ,Disease Susceptibility ,Protein Kinases ,010606 plant biology & botany - Abstract
Septoria nodorum blotch (SNB), a disease caused by the necrotrophic fungal pathogen Parastagonospora nodorum, is a threat to wheat (Triticum aestivum) production worldwide. Multiple inverse gene-for-gene interactions involving the recognition of necrotrophic effectors (NEs) by wheat sensitivity genes play major roles in causing SNB. One interaction involves the wheat gene Snn3 and the P. nodorum NE SnTox3. Here, we used a map-based strategy to clone the Snn3-D1 gene from Aegilops tauschii, the D-genome progenitor of common wheat. Snn3-D1 contained protein kinase and major sperm protein domains, both of which were essential for function as confirmed by mutagenesis. As opposed to other characterized interactions in this pathosystem, a compatible Snn3-D1-SnTox3 interaction was light-independent, and Snn3-D1 transcriptional expression was downregulated by light and upregulated by darkness. Snn3-D1 likely emerged in Ae. tauschii due to an approximately 218-kb insertion that occurred along the west bank of the Caspian Sea. The identification of this new class of NE sensitivity genes combined with the previously cloned sensitivity genes demonstrates that P. nodorum can take advantage of diverse host targets to trigger SNB susceptibility in wheat.
- Published
- 2021
13. A protein kinase–major sperm protein gene hijacked by a necrotrophic fungal pathogen triggers disease susceptibility in wheat.
- Author
-
Zhang, Zengcui, Running, Katherine L. D., Seneviratne, Sudeshi, Peters Haugrud, Amanda R., Szabo‐Hever, Agnes, Shi, Gongjun, Brueggeman, Robert, Xu, Steven S., Friesen, Timothy L., and Faris, Justin D.
- Subjects
DISEASE susceptibility ,WHEAT ,PROTEIN domains ,SPERMATOZOA ,PROTEIN kinases - Abstract
SUMMARY: Septoria nodorum blotch (SNB), a disease caused by the necrotrophic fungal pathogen Parastagonospora nodorum, is a threat to wheat (Triticum aestivum) production worldwide. Multiple inverse gene‐for‐gene interactions involving the recognition of necrotrophic effectors (NEs) by wheat sensitivity genes play major roles in causing SNB. One interaction involves the wheat gene Snn3 and the P. nodorum NE SnTox3. Here, we used a map‐based strategy to clone the Snn3‐D1 gene from Aegilops tauschii, the D‐genome progenitor of common wheat. Snn3‐D1 contained protein kinase and major sperm protein domains, both of which were essential for function as confirmed by mutagenesis. As opposed to other characterized interactions in this pathosystem, a compatible Snn3‐D1–SnTox3 interaction was light‐independent, and Snn3‐D1 transcriptional expression was downregulated by light and upregulated by darkness. Snn3‐D1 likely emerged in Ae. tauschii due to an approximately 218‐kb insertion that occurred along the west bank of the Caspian Sea. The identification of this new class of NE sensitivity genes combined with the previously cloned sensitivity genes demonstrates that P. nodorum can take advantage of diverse host targets to trigger SNB susceptibility in wheat. Significance Statement: Necrotrophic effectors produced by the necrotrophic fungal pathogen Parastagonospora nodorum can be recognized by wheat (Triticum aestivum) sensitivity genes to cause septoria nodorum blotch (SNB), a fungal disease posing a threat to wheat production worldwide. Here, we cloned a new type of wheat sensitivity gene containing protein kinase and major sperm protein domains, which furthered our understanding of how P. nodorum takes advantage of diverse host targets to trigger SNB susceptibility in wheat. [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
- View/download PDF
14. Evaluation of Genetic Diversity and Host Resistance to Stem Rust in USDA NSGC Durum Wheat Accessions
- Author
-
Maricelis Acevedo, Daryl L. Klindworth, Shiaoman Chao, Steven S. Xu, J. Michael Bonman, Agnes Szabo-Hever, Harold E. Bockelman, Matthew N. Rouse, and Elias M. Elias
- Subjects
0106 biological sciences ,0301 basic medicine ,Germplasm ,lcsh:QH426-470 ,Plant Science ,Plant disease resistance ,lcsh:Plant culture ,Genes, Plant ,Stem rust ,Polymorphism, Single Nucleotide ,01 natural sciences ,Chromosomes, Plant ,Linkage Disequilibrium ,03 medical and health sciences ,Genetic variation ,Genetics ,lcsh:SB1-1110 ,Plant breeding ,Triticum ,Genetic diversity ,biology ,Basidiomycota ,Genetic Variation ,food and beverages ,biology.organism_classification ,lcsh:Genetics ,030104 developmental biology ,Agronomy ,Genetic distance ,Genetic marker ,Agronomy and Crop Science ,Genome-Wide Association Study ,010606 plant biology & botany - Abstract
The USDA–ARS National Small Grains Collection (NSGC) maintains germplasm representing global diversity of small grains and their wild relatives. To evaluate the utility of the NSGC durum wheat ( L. ssp. ) accessions, we assessed genetic diversity and linkage disequilibrium (LD) patterns in a durum core subset containing 429 lines with spring growth habit originating from 64 countries worldwide. Genetic diversity estimated using wheat single-nucleotide polymorphism (SNP) markers showed considerable diversity captured in this collection. Average LD decayed over a genetic distance to within 3 cM at = 0.2, with a fast LD decay for markers linked at >5 cM. We evaluated accessions for resistance to wheat stem rust, caused by a fungal pathogen, Pers. Pers. f. sp. Eriks. and E. Henn (), using races from both eastern Africa and North America, at seedling and adult plant stages. Five accessions were identified as resistant to all stem rust pathogen races evaluated. Genome-wide association analysis detected 17 significant associations at the seedling stage with nine likely corresponding to , , and and the remaining potentially being novel genes located on six chromosomes. A higher frequency of resistant accessions was found at the adult plant stage than at the seedling stage. However, few significant associations were detected possibly a result of strong G × E interactions not properly accounted for in the mixed model. Nonetheless, the resistant accessions identified in this study should provide wheat breeders with valuable resources for improving stem rust resistance.
- Published
- 2017
15. Evolution, diversity, and function of the disease susceptibility gene Snn1 in wheat.
- Author
-
Seneviratne, Sudeshi, Shi, Gongjun, Szabo‐Hever, Agnes, Zhang, Zengcui, Peters Haugrud, Amanda R., Running, Katherine L. D., Singh, Gurminder, Nandety, Raja Sekhar, Fiedler, Jason D., McClean, Phillip E., Xu, Steven S., Friesen, Timothy L., and Faris, Justin D.
- Abstract
SUMMARY Septoria nodorum blotch (SNB), caused by Parastagonospora nodorum, is a disease of durum and common wheat initiated by the recognition of pathogen‐produced necrotrophic effectors (NEs) by specific wheat genes. The wheat gene Snn1 was previously cloned, and it encodes a wall‐associated kinase that directly interacts with the NE SnTox1 leading to programmed cell death and ultimately the development of SNB. Here, sequence analysis of Snn1 from 114 accessions including diploid, tetraploid, and hexaploid wheat species revealed that some wheat lines possess two copies of Snn1 (designated Snn1‐B1 and Snn1‐B2) approximately 120 kb apart. Snn1‐B2 evolved relatively recently as a paralog of Snn1‐B1, and both genes have undergone diversifying selection. Three point mutations associated with the formation of the first SnTox1‐sensitive Snn1‐B1 allele from a primitive wild wheat were identified. Four subsequent and independent SNPs, three in Snn1‐B1 and one in Snn1‐B2, converted the sensitive alleles to insensitive forms. Protein modeling indicated these four mutations could abolish Snn1–SnTox1 compatibility either through destabilization of the Snn1 protein or direct disruption of the protein–protein interaction. A high‐throughput marker was developed for the absent allele of Snn1, and it was 100% accurate at predicting SnTox1‐insensitive lines in both durum and spring wheat. Results of this study increase our understanding of the evolution, diversity, and function of Snn1‐B1 and Snn1‐B2 genes and will be useful for marker‐assisted elimination of these genes for better host resistance. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
16. Genetic Diversity and Resistance to Fusarium Head Blight in Synthetic Hexaploid Wheat Derived From Aegilops tauschii and Diverse Triticum turgidum Subspecies.
- Author
-
Szabo-Hever, Agnes, Zhang, Qijun, Friesen, Timothy L., Zhong, Shaobin, Elias, Elias M., Cai, Xiwen, Jin, Yue, Faris, Justin D., Chao, Shiaoman, and Xu, Steven S.
- Subjects
EMMER wheat ,WHEAT genetics ,SINGLE nucleotide polymorphisms - Abstract
Synthetic hexaploid wheat (SHW) can serve as a bridge for the transfer of useful genes from Aegilops tauschii and tetraploid wheat (Triticum turgidum) into common wheat (T. aestivum). The objective of this study was to evaluate 149 SHW lines and their 74 tetraploid parents for their genetic diversity, breeding values and inter-genomic interactions for resistance to Fusarium head blight (FHB). The genetic diversity analysis was performed based on the population structure established using 4,674 and 3,330 polymorphic SNP markers among the SHW lines and tetraploid parents, respectively. The results showed that all T. carthlicum and most T. dicoccum accessions formed different clusters and subpopulations, respectively, whereas all the T. durum , T. polonicum , T. turgidum , and T. turanicum accessions were clustered together, suggesting that T. durum was more closely related to T. polonicum , T. turgidum , and T. turanicum than to T. dicoccum. The genetic diversity of the SHW lines mainly reflected that of the tetraploid parents. The SHW lines and their tetraploid parents were evaluated for reactions to FHB in two greenhouse seasons and at two field nurseries for 2 years. As expected, most of the SHW lines were more resistant than their tetraploid parents in all environments. The FHB severities of the SHW lines varied greatly depending on the Ae. tauschii and tetraploid genotypes involved. Most of the SHW lines with a high level of FHB resistance were generally derived from the tetraploid accessions with a high level of FHB resistance. Among the 149 SHW lines, 140 were developed by using three Ae. tauschii accessions CIae 26, PI 268210, and RL 5286. These SHW lines showed FHB severities reduced by 21.7%, 17.3%, and 11.5%, respectively, with an average reduction of 18.3%, as compared to the tetraploid parents, suggesting that the D genome may play a major role in reducing disease severity in the SHW lines. Thirteen SHW lines consistently showed a high level of FHB resistance compared to the resistant check, Sumai 3, in each environment. These SHW lines will be useful for the development of FHB-resistant wheat germplasm and populations for discovery of novel FHB resistance genes. [ABSTRACT FROM AUTHOR]
- Published
- 2018
- Full Text
- View/download PDF
17. Alternaria hungarica sp. nov., a minor foliar pathogen of wheat in Hungary
- Author
-
Toth, B., Csosz, Maria, Szabo-Hever, Agnes, Simmons, Emory G., Samson, R.A., Varga, J., Toth, B., Csosz, Maria, Szabo-Hever, Agnes, Simmons, Emory G., Samson, R.A., and Varga, J.
- Published
- 2011
18. Two Major Resistance Quantitative Trait Loci are Required to Counteract the Increased Susceptibility to Fusarium Head Blight of the Dwarfing Gene in Wheat
- Author
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Lu, Qiongxian, Szabo-Hever, Agnes, Bjørnstad, Åsmund, Lillemo, Morten, Semagn, Kassa, Mesterhazy, Akos, Ji, Fang, Shi, Jianrong, and Skinnes, Helge
- Published
- 2011
- Full Text
- View/download PDF
19. Two Major Resistance Quantitative Trait Loci are Required to Counteract the Increased Susceptibility to Fusarium Head Blight of the Rht-D1b Dwarfing Gene in Wheat.
- Author
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Lua, Qiongxian, Szabo-Hever, Agnes, Bjørnstad, Åsmund, Lillemo, Morten, Semagn, Kassa, Mesterhazy, Akos, Ji, Fang, Shi, Jianrong, and Skinnes, Helge
- Subjects
- *
WHEAT varieties , *FUSARIUM , *HAPLOIDY , *CROP science , *AGRICULTURAL research , *INOCULATION of crops - Abstract
Fusarium head blight (FHB) isa destructive wheat (Triticum aestivum L.) disease of global importance. The widely used dwarfing allele Rht-Dlb has recently been shown to compromise FHB resistance. The objectives of this study were to investigate the impact of this dwarfing allele in a segregating population with major resistance quantitative trait loci (OIL) derived from 'Sumai 3' and Nobeokabozu, and to determine how many resistance OIL are needed to counteract its negative effect. Fusarium head blight resistance was evaluated in four field trials with spray inoculation and two field trials with point inoculation in a double-haploid (DH) population from a cross between the Swedish cv. Avie (susceptible spring type; wild-type allele Rht-Dla) and Line 685 (resistant winter type; semi-dwarf allele Rht-Dlb). The Rht-D1 locus explained up to 38% of the phenotypic variation and was the most important QTL for FHB severity under spray inoculation but did not show any~ effect after point inoculation. Fhbl on 3B5 was detected with both inoculation methods but was relatively more important after point inoculation. Another two OIL on 5A and 2BL were detected after spray inoculation and a QTL on 2D after point inoculation. Comparison of phenotypic effects of different allele combinations revealed that a combination of both Fhbl and the 5A QTL was required to counteract the increased susceptibility of Rht-Dlb. Although breeding of FHB resistant cultivars with this dwarfing allele is possible, it requires the pyramiding of several resistant QTL to achieve adequate levels of resistance. [ABSTRACT FROM AUTHOR]
- Published
- 2011
- Full Text
- View/download PDF
20. Two Major Resistance Quantitative Trait Loci are Required to Counteract the Increased Susceptibility to Fusarium Head Blight of the Rht‐D1bDwarfing Gene in Wheat
- Author
-
Lu, Qiongxian, Szabo‐Hever, Agnes, Bjørnstad, Åsmund, Lillemo, Morten, Semagn, Kassa, Mesterhazy, Akos, Ji, Fang, Shi, Jianrong, and Skinnes, Helge
- Abstract
Fusarium head blight (FHB) is a destructive wheat (Triticum aestivumL.) disease of global importance. The widely used dwarfing allele Rht‐D1bhas recently been shown to compromise FHB resistance. The objectives of this study were to investigate the impact of this dwarfing allele in a segregating population with major resistance quantitative trait loci (QTL) derived from ‘Sumai‐3’ and Nobeokabozu, and to determine how many resistance QTL are needed to counteract its negative effect. Fusarium head blight resistance was evaluated in four field trials with spray inoculation and two field trials with point inoculation in a double‐haploid (DH) population from a cross between the Swedish cv. Avle (susceptible spring type; wild‐type allele Rht‐D1a) and Line 685 (resistant winter type; semi‐dwarf allele Rht‐D1b). The Rht‐D1locus explained up to 38% of the phenotypic variation and was the most important QTL for FHB severity under spray inoculation but did not show any effect after point inoculation. Fhb1on 3BS was detected with both inoculation methods but was relatively more important after point inoculation. Another two QTL on 5A and 2BL were detected after spray inoculation and a QTL on 2D after point inoculation. Comparison of phenotypic effects of different allele combinations revealed that a combination of both Fhb1and the 5A QTL was required to counteract the increased susceptibility of Rht‐D1b. Although breeding of FHB resistant cultivars with this dwarfing allele is possible, it requires the pyramiding of several resistant QTL to achieve adequate levels of resistance.
- Published
- 2011
- Full Text
- View/download PDF
21. Evaluation of Genetic Diversity and Host Resistance to Stem Rust in USDA NSGC Durum Wheat Accessions.
- Author
-
Chao S, Rouse MN, Acevedo M, Szabo-Hever A, Bockelman H, Bonman JM, Elias E, Klindworth D, and Xu S
- Subjects
- Chromosomes, Plant, Genes, Plant, Genome-Wide Association Study, Linkage Disequilibrium, Polymorphism, Single Nucleotide, Triticum immunology, Basidiomycota pathogenicity, Genetic Variation, Triticum genetics, Triticum microbiology
- Abstract
The USDA-ARS National Small Grains Collection (NSGC) maintains germplasm representing global diversity of small grains and their wild relatives. To evaluate the utility of the NSGC durum wheat ( L. ssp. ) accessions, we assessed genetic diversity and linkage disequilibrium (LD) patterns in a durum core subset containing 429 lines with spring growth habit originating from 64 countries worldwide. Genetic diversity estimated using wheat single-nucleotide polymorphism (SNP) markers showed considerable diversity captured in this collection. Average LD decayed over a genetic distance to within 3 cM at = 0.2, with a fast LD decay for markers linked at >5 cM. We evaluated accessions for resistance to wheat stem rust, caused by a fungal pathogen, Pers. Pers. f. sp. Eriks. and E. Henn (), using races from both eastern Africa and North America, at seedling and adult plant stages. Five accessions were identified as resistant to all stem rust pathogen races evaluated. Genome-wide association analysis detected 17 significant associations at the seedling stage with nine likely corresponding to , , and and the remaining potentially being novel genes located on six chromosomes. A higher frequency of resistant accessions was found at the adult plant stage than at the seedling stage. However, few significant associations were detected possibly a result of strong G × E interactions not properly accounted for in the mixed model. Nonetheless, the resistant accessions identified in this study should provide wheat breeders with valuable resources for improving stem rust resistance., (Copyright © 2017 Crop Science Society of America.)
- Published
- 2017
- Full Text
- View/download PDF
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