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Amouzoune M, Rehman S, Benkirane R, Udupa S, Mamidi S, Kehel Z, Al-Jaboobi M, Amri A. Genome wide association study of seedling and adult plant leaf rust resistance in two subsets of barley genetic resources. Sci Rep 2024; 14:15428. [PMID: 38965257 PMCID: PMC11224298 DOI: 10.1038/s41598-024-53149-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2023] [Accepted: 01/29/2024] [Indexed: 07/06/2024] Open
Abstract
Leaf rust (LR) caused by Puccinia hordei is a serious disease of barley worldwide, causing significant yield losses and reduced grain quality. Discovery and incorporation of new sources of resistance from gene bank accessions into barley breeding programs is essential for the development of leaf rust resistant varieties. To identify Quantitative Trait Loci (QTL) conferring LR resistance in the two barley subsets, the Generation Challenge Program (GCP) reference set of 142 accessions and the leaf rust subset constructed using the Focused Identification of Germplasm Strategy (FIGS) of 76 barley accessions, were genotyped to conduct a genome-wide association study (GWAS). The results revealed a total of 59 QTL in the 218 accessions phenotyped against barley leaf rust at the seedling stage using two P. hordei isolates (ISO-SAT and ISO-MRC), and at the adult plant stage in four environments in Morocco. Out of these 59 QTL, 10 QTL were associated with the seedling resistance (SR) and 49 QTL were associated with the adult plant resistance (APR). Four QTL showed stable effects in at least two environments for APR, whereas two common QTL associated with SR and APR were detected on chromosomes 2H and 7H. Furthermore, 39 QTL identified in this study were potentially novel. Interestingly, the sequences of 27 SNP markers encoded the candidate genes (CGs) with predicted protein functions in plant disease resistance. These results will provide new perspectives on the diversity of leaf rust resistance loci for fine mapping, isolation of resistance genes, and for marker-assisted selection for the LR resistance in barley breeding programs worldwide.
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Affiliation(s)
- Mariam Amouzoune
- Faculty of Sciences, University Ibn Tofail, 14000, Kenitra, Morocco.
- Biodiversity and Crop Improvement Program, International Center for Agricultural Research in the Dry Areas (ICARDA), 10100, Rabat, Morocco.
| | - Sajid Rehman
- Biodiversity and Crop Improvement Program, International Center for Agricultural Research in the Dry Areas (ICARDA), 10100, Rabat, Morocco
- Field Crop Development Center, The Olds College, Lacombe, AB, T4L 1W8, Canada
| | - Rachid Benkirane
- Faculty of Sciences, University Ibn Tofail, 14000, Kenitra, Morocco
| | - Sripada Udupa
- Biodiversity and Crop Improvement Program, International Center for Agricultural Research in the Dry Areas (ICARDA), 10100, Rabat, Morocco
| | - Sujan Mamidi
- Hudson Alpha Institute for Biotechnology, 601 Genome Way Northwest, Huntsville, AL, 35806, USA
| | - Zakaria Kehel
- Biodiversity and Crop Improvement Program, International Center for Agricultural Research in the Dry Areas (ICARDA), 10100, Rabat, Morocco
| | - Muamer Al-Jaboobi
- Biodiversity and Crop Improvement Program, International Center for Agricultural Research in the Dry Areas (ICARDA), 10100, Rabat, Morocco
| | - Ahmed Amri
- Biodiversity and Crop Improvement Program, International Center for Agricultural Research in the Dry Areas (ICARDA), 10100, Rabat, Morocco
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Rossi N, Powell W, Mackay IJ, Hickey L, Maurer A, Pillen K, Halliday K, Sharma R. Investigating the genetic control of plant development in spring barley under speed breeding conditions. TAG. THEORETICAL AND APPLIED GENETICS. THEORETISCHE UND ANGEWANDTE GENETIK 2024; 137:115. [PMID: 38691245 PMCID: PMC11063105 DOI: 10.1007/s00122-024-04618-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/12/2023] [Accepted: 04/08/2024] [Indexed: 05/03/2024]
Abstract
KEY MESSAGE This study found that the genes, PPD-H1 and ELF3, control the acceleration of plant development under speed breeding, with important implications for optimizing the delivery of climate-resilient crops. Speed breeding is a tool to accelerate breeding and research programmes. Despite its success and growing popularity with breeders, the genetic basis of plant development under speed breeding remains unknown. This study explored the developmental advancements of barley genotypes under different photoperiod regimes. A subset of the HEB-25 Nested Association Mapping population was evaluated for days to heading and maturity under two contrasting photoperiod conditions: (1) Speed breeding (SB) consisting of 22 h of light and 2 h of darkness, and (2) normal breeding (NB) consisting of 16 h of light and 8 h of darkness. GWAS revealed that developmental responses under both conditions were largely controlled by two loci: PPDH-1 and ELF3. Allelic variants at these genes determine whether plants display early flowering and maturity under both conditions. At key QTL regions, domesticated alleles were associated with late flowering and maturity in NB and early flowering and maturity in SB, whereas wild alleles were associated with early flowering under both conditions. We hypothesize that this is related to the dark-dependent repression of PPD-H1 by ELF3 which might be more prominent in NB conditions. Furthermore, by comparing development under two photoperiod regimes, we derived an estimate of plasticity for the two traits. Interestingly, plasticity in development was largely attributed to allelic variation at ELF3. Our results have important implications for our understanding and optimization of speed breeding protocols particularly for introgression breeding and the design of breeding programmes to support the delivery of climate-resilient crops.
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Affiliation(s)
- Nicola Rossi
- Scotland's Rural College (SRUC), Kings Buildings, West Mains Road, Edinburgh, EH9 3JG, UK
- Institute of Molecular Plant Sciences, School of Biological Sciences, University of Edinburgh, Edinburgh, EH9 3BF, UK
| | - Wayne Powell
- Scotland's Rural College (SRUC), Kings Buildings, West Mains Road, Edinburgh, EH9 3JG, UK
| | - Ian J Mackay
- Scotland's Rural College (SRUC), Kings Buildings, West Mains Road, Edinburgh, EH9 3JG, UK
| | - Lee Hickey
- Queensland Alliance for Agriculture and Food Innovation, The University of Queensland, Brisbane, Australia
| | - Andreas Maurer
- Chair of Plant Breeding, Martin-Luther-University Halle-Wittenberg, Betty-Heimann-Str. 3, 06120, Halle, Germany
| | - Klaus Pillen
- Chair of Plant Breeding, Martin-Luther-University Halle-Wittenberg, Betty-Heimann-Str. 3, 06120, Halle, Germany
| | - Karen Halliday
- Institute of Molecular Plant Sciences, School of Biological Sciences, University of Edinburgh, Edinburgh, EH9 3BF, UK
| | - Rajiv Sharma
- Scotland's Rural College (SRUC), Kings Buildings, West Mains Road, Edinburgh, EH9 3JG, UK.
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Nazareno ES, Matny O, Jin Y, Fetch T, Rouse MN, Steffenson BJ. Virulence Dynamics of the Barley Leaf Rust Pathogen ( Puccinia hordei) in the United States from 1989 to 2020. PLANT DISEASE 2023; 107:3952-3957. [PMID: 37415351 DOI: 10.1094/pdis-03-23-0583-re] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/08/2023]
Abstract
Barley leaf rust, caused by Puccinia hordei, is an important disease of barley worldwide. The pathogen can develop new races that overcome resistance genes, emphasizing the need for monitoring its virulence. This study characterized 519 P. hordei isolates collected in the United States from the 1989 to 2000 and 2010 to 2020 survey periods on 15 Rph (Reaction to Puccinia hordei) genes. We analyzed linearized infection type data to detect virulence patterns across the United States and in five geographical regions: Pacific/West (PW), Southwest (SW), Midwest (MW), Northeast (NE), and Southeast (SE). Over 32 years, we observed high mean infection scores for Rph1.a, Rph4.d, and Rph8.h; intermediate scores for Rph2.b, Rph9.i, Rph10.o, Rph11.p, and Rph13.x; and low scores for Rph3.c, Rph5.e, Rph5.f, Rph7.g, Rph9.z, Rph14.ab, and Rph15.ad. Virulence for Rph2.b, Rph3.c, Rph5.e, Rph9.z, Rph10.o, Rph11.p, and Rph13.x significantly differed between the two survey periods. From 1989 to 2020, regional patterns of virulence were found for Rph5.e, Rph5.f, Rph7.g, and Rph14.ab, while regionalities of virulence for Rph3.c, Rph9.i, Rph9.z were only observed in the 2010 to 2020 survey period. Virulence associations were also detected in the P. hordei population. Notably, isolates that were virulent to Rph5.e and Rph6.f were more likely to be avirulent to Rph7.g and Rph13.x, and vice versa. In decreasing order of effectiveness, Rph15.ad, Rph5.e, Rph3.c, Rph9.z, Rph7.g, Rph5.f, and Rph14.ab were the most effective Rph genes in the United States from 1989 to 2020. Pyramiding Rph15.ad with other widely effective Rph and adult plant resistance genes may provide long-lasting resistance against P. hordei.
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Affiliation(s)
- Eric S Nazareno
- Department of Plant Pathology, University of Minnesota, St. Paul, MN, U.S.A
| | - Oadi Matny
- Department of Plant Pathology, University of Minnesota, St. Paul, MN, U.S.A
| | - Yue Jin
- Department of Plant Pathology, University of Minnesota, St. Paul, MN, U.S.A
- Cereal Disease Laboratory, USDA-Agricultural Research Service, St. Paul, MN, U.S.A
| | - Thomas Fetch
- Morden Research Centre, Agriculture and Agri-Food Canada, Morden, Manitoba, Canada
| | - Matthew N Rouse
- Department of Plant Pathology, University of Minnesota, St. Paul, MN, U.S.A
- Cereal Disease Laboratory, USDA-Agricultural Research Service, St. Paul, MN, U.S.A
| | - Brian J Steffenson
- Department of Plant Pathology, University of Minnesota, St. Paul, MN, U.S.A
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Chen C, Jost M, Outram MA, Friendship D, Chen J, Wang A, Periyannan S, Bartoš J, Holušová K, Doležel J, Zhang P, Bhatt D, Singh D, Lagudah E, Park RF, Dracatos PM. A pathogen-induced putative NAC transcription factor mediates leaf rust resistance in barley. Nat Commun 2023; 14:5468. [PMID: 37673864 PMCID: PMC10482968 DOI: 10.1038/s41467-023-41021-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2022] [Accepted: 08/21/2023] [Indexed: 09/08/2023] Open
Abstract
Leaf rust, caused by Puccinia hordei, is one of the most widespread and damaging foliar diseases affecting barley. The barley leaf rust resistance locus Rph7 has been shown to have unusually high sequence and haplotype divergence. In this study, we isolate the Rph7 gene using a fine mapping and RNA-Seq approach that is confirmed by mutational analysis and transgenic complementation. Rph7 is a pathogen-induced, non-canonical resistance gene encoding a protein that is distinct from other known plant disease resistance proteins in the Triticeae. Structural analysis using an AlphaFold2 protein model suggests that Rph7 encodes a putative NAC transcription factor with a zinc-finger BED domain with structural similarity to the N-terminal DNA-binding domain of the NAC transcription factor (ANAC019) from Arabidopsis. A global gene expression analysis suggests Rph7 mediates the activation and strength of the basal defence response. The isolation of Rph7 highlights the diversification of resistance mechanisms available for engineering disease control in crops.
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Affiliation(s)
- Chunhong Chen
- CSIRO Agriculture and Food, Commonwealth Scientific and Industrial Research Organisation, GPO Box 1700, Canberra, ACT, 2601, Australia
| | - Matthias Jost
- CSIRO Agriculture and Food, Commonwealth Scientific and Industrial Research Organisation, GPO Box 1700, Canberra, ACT, 2601, Australia
| | - Megan A Outram
- CSIRO Agriculture and Food, Commonwealth Scientific and Industrial Research Organisation, GPO Box 1700, Canberra, ACT, 2601, Australia
| | - Dorian Friendship
- The University of Sydney, Faculty of Science, Plant Breeding Institute, Cobbitty, NSW, 2570, Australia
| | - Jian Chen
- CSIRO Agriculture and Food, Commonwealth Scientific and Industrial Research Organisation, GPO Box 1700, Canberra, ACT, 2601, Australia
| | - Aihua Wang
- CSIRO Agriculture and Food, Commonwealth Scientific and Industrial Research Organisation, GPO Box 1700, Canberra, ACT, 2601, Australia
| | - Sambasivam Periyannan
- CSIRO Agriculture and Food, Commonwealth Scientific and Industrial Research Organisation, GPO Box 1700, Canberra, ACT, 2601, Australia
- The University of Southern Queensland, School of Agriculture and Environmental Science, Centre for Crop Health, Toowoomba, QLD, 4350, Australia
| | - Jan Bartoš
- Institute of Experimental Botany, Centre of Plant Structural and Functional Genomics, Olomouc, CZ-77900, Czech Republic
| | - Kateřina Holušová
- Institute of Experimental Botany, Centre of Plant Structural and Functional Genomics, Olomouc, CZ-77900, Czech Republic
| | - Jaroslav Doležel
- Institute of Experimental Botany, Centre of Plant Structural and Functional Genomics, Olomouc, CZ-77900, Czech Republic
| | - Peng Zhang
- The University of Sydney, Faculty of Science, Plant Breeding Institute, Cobbitty, NSW, 2570, Australia
| | - Dhara Bhatt
- CSIRO Agriculture and Food, Commonwealth Scientific and Industrial Research Organisation, GPO Box 1700, Canberra, ACT, 2601, Australia
| | - Davinder Singh
- The University of Sydney, Faculty of Science, Plant Breeding Institute, Cobbitty, NSW, 2570, Australia
| | - Evans Lagudah
- CSIRO Agriculture and Food, Commonwealth Scientific and Industrial Research Organisation, GPO Box 1700, Canberra, ACT, 2601, Australia.
| | - Robert F Park
- The University of Sydney, Faculty of Science, Plant Breeding Institute, Cobbitty, NSW, 2570, Australia.
| | - Peter M Dracatos
- The University of Sydney, Faculty of Science, Plant Breeding Institute, Cobbitty, NSW, 2570, Australia.
- La Trobe Institute for Sustainable Agriculture & Food (LISAF), Department of Animal, Plant and Soil Sciences, La Trobe University, Melbourne, VIC, 3086, Australia.
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5
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Wang Z, Li Q, Liu C, Liu F, Xu N, Yao M, Yu H, Wang Y, Chen J, Bai S, Yang J, Sun G, Long J, Fan Y, Kang L, Li H, Zhang X, Liu S. Development and identification of an elite wheat-Hordeum californicum T6HcS/6BL translocation line ND646 containing several desirable traits. Genet Mol Biol 2022; 45:e20220117. [PMID: 36214618 PMCID: PMC9549530 DOI: 10.1590/1678-4685-gmb-2022-0117] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2022] [Accepted: 08/18/2022] [Indexed: 11/04/2022] Open
Abstract
Hordeum californicum (H. californicum,
2n=2X=14, HcHc), one of the wild relatives of wheat
(Triticum aestivum L.), harbors many desirable genes and is
a potential genetic resource for wheat improvement. In this study, an elite line
ND646 was selected from a BC4F5 population, which was
developed using 60Co-γ irradiated wheat-H.
californicum disomic addition line WJ28-1 (DA6Hc) as the
donor parent and Ningchun 4 as the recurrent parent. ND646 was identified as a
novel wheat-H. californicum 6HcS/6BL translocation
line using genomic in situ hybridization (GISH), fluorescence
in situ hybridization (FISH), and H.
californicum-specific expressed sequence tag (EST) markers. Further
evaluation revealed that ND646 had excellent performance in several traits, such
as a higher sedimentation value (SV), higher water absorption rate (WAR), and
higher hardness index (HI). More importantly, it had more kernels per spike
(KPS), a higher grain yields (GY), and good resistance to powdery mildew, leaf
rust, and 2,4-D butylate (2,4-D). Its excellent phenotypic performance laid the
foundation for further investigation of its genetic architecture and makes ND646
a useful germplasm resource for wheat breeding.
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Affiliation(s)
- Zhangjun Wang
- Nanjing Agricultural University, Cytogenetics Institute, State Key
Laboratory of Crop Genetics and Germplasm Enhancement, Nanjing, Jiangsu,
China.,Ningxia University, School of Agriculture, Yinchuan, Ningxia,
China
| | - Qingfeng Li
- Ningxia University, School of Agriculture, Yinchuan, Ningxia,
China.,*Send correspondence to Qingfeng Li. Ningxia University, School of
Agriculture, 489 Helanshan West Rd., Xixia District, Yinchuan, Ningxia province,
China. E-mail:
| | - Caixia Liu
- Ningxia University, School of Agriculture, Yinchuan, Ningxia,
China
| | - Fenglou Liu
- Ningxia University, School of Agriculture, Yinchuan, Ningxia,
China
| | - Nali Xu
- Ningxia University, School of Agriculture, Yinchuan, Ningxia,
China
| | - Mingming Yao
- Ningxia University, School of Agriculture, Yinchuan, Ningxia,
China
| | - Huixia Yu
- Ningxia University, School of Agriculture, Yinchuan, Ningxia,
China
| | - Yanqing Wang
- Ningxia University, School of Agriculture, Yinchuan, Ningxia,
China
| | - Jiajing Chen
- Ningxia University, School of Agriculture, Yinchuan, Ningxia,
China
| | - Shuangyu Bai
- Ningxia University, School of Agriculture, Yinchuan, Ningxia,
China
| | - Jingxin Yang
- Ningxia University, School of Agriculture, Yinchuan, Ningxia,
China
| | - Gang Sun
- Ningxia University, School of Agriculture, Yinchuan, Ningxia,
China
| | - Jiaohui Long
- Ningxia University, School of Agriculture, Yinchuan, Ningxia,
China
| | - Yalei Fan
- Ningxia University, School of Agriculture, Yinchuan, Ningxia,
China
| | - Ling Kang
- Ningxia Academy of Agricultural-Forestry Sciences, Institute of Crop
Sciences, Yinchuan, Ningxia, China
| | - Hongxia Li
- Ningxia Academy of Agricultural-Forestry Sciences, Institute of Crop
Sciences, Yinchuan, Ningxia, China
| | - Xiaogang Zhang
- Ningxia University, School of Agriculture, Yinchuan, Ningxia,
China
| | - Shengxiang Liu
- Ningxia University, School of Agriculture, Yinchuan, Ningxia,
China
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Mehnaz M, Dracatos PM, Dinh HX, Forrest K, Rouse MN, Park RF, Singh D. A novel locus conferring resistance to Puccinia hordei maps to the genomic region corresponding to Rph14 on barley chromosome 2HS. FRONTIERS IN PLANT SCIENCE 2022; 13:980870. [PMID: 36275572 PMCID: PMC9583899 DOI: 10.3389/fpls.2022.980870] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/29/2022] [Accepted: 08/24/2022] [Indexed: 06/16/2023]
Abstract
Barley leaf rust (BLR), caused by Puccinia hordei, is best controlled through genetic resistance. An efficient resistance breeding program prioritizes the need to identify, characterize, and map new sources of resistance as well as understanding the effectiveness, structure, and function of resistance genes. In this study, three mapping populations were developed by crossing Israelian barley lines "AGG-396," "AGG-397," and "AGG-403" (carrying unknown leaf rust resistance) with a susceptible variety "Gus" to characterize and map resistance. Genetic analysis of phenotypic data from rust testing F3s with a P. hordei pathotype 5457 P+ revealed monogenic inheritance in all three populations. Targeted genotyping-by-sequencing of the three populations detected marker trait associations in the same genomic region on the short arm of chromosome 2H between 39 and 57 Mb (AGG-396/Gus), 44 and 64 Mb (AGG-397/Gus), and 31 and 58 Mb (AGG-403/Gus), suggesting that the resistance in all three lines is likely conferred by the same locus (tentatively designated RphAGG396). Two Kompetitive allele-specific PCR (KASP) markers, HvGBSv2-902 and HvGBSv2-932, defined a genetic distance of 3.8 cM proximal and 7.1 cM distal to RphAGG396, respectively. To increase the marker density at the RphAGG396 locus, 75 CAPS markers were designed between two flanking markers. Integration of marker data resulted in the identification of two critical recombinants and mapping RphAGG396 between markers- Mloc-28 (40.75 Mb) and Mloc-41 (41.92 Mb) narrowing the physical window to 1.17 Mb based on the Morex v2.0 reference genome assembly. To enhance map resolution, 600 F2s were genotyped with markers- Mloc-28 and Mloc-41 and nine recombinants were identified, placing the gene at a genetic distance of 0.5 and 0.2 cM between the two markers, respectively. Two annotated NLR (nucleotide-binding domain leucine-rich repeat) genes (r2.2HG0093020 and r2.2HG0093030) were identified as the best candidates for RphAGG396. A closely linked marker was developed for RphAGG396 that can be used for marker-assisted selection.
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Affiliation(s)
- Mehnaz Mehnaz
- School of Life and Environmental Sciences, Plant Breeding Institute, University of Sydney, Sydney, NSW, Australia
| | - Peter M. Dracatos
- Department of Animal, Plant and Soil Sciences, La Trobe University, AgriBio, Bundoora, VIC, Australia
| | - Hoan X. Dinh
- School of Life and Environmental Sciences, Plant Breeding Institute, University of Sydney, Sydney, NSW, Australia
| | - Kerrie Forrest
- Agriculture Victoria, AgriBio, Centre for AgriBioscience, Bundoora, VIC, Australia
| | - Matthew N. Rouse
- USDA-ARS Cereal Disease Laboratory, Department of Plant Pathology, University of Minnesota, St. Paul, MN, United States
| | - Robert F. Park
- School of Life and Environmental Sciences, Plant Breeding Institute, University of Sydney, Sydney, NSW, Australia
| | - Davinder Singh
- School of Life and Environmental Sciences, Plant Breeding Institute, University of Sydney, Sydney, NSW, Australia
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Dinh HX, Pourkheirandish M, Park RF, Singh D. The genetic basis and interaction of genes conferring resistance to Puccinia hordei in an ICARDA barley breeding line GID 5779743. FRONTIERS IN PLANT SCIENCE 2022; 13:988322. [PMID: 36051292 PMCID: PMC9425046 DOI: 10.3389/fpls.2022.988322] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/07/2022] [Accepted: 07/27/2022] [Indexed: 06/15/2023]
Abstract
Leaf rust of barley causes significant losses in crops of susceptible cultivars. Deploying host resistance is the most cost-effective and eco-sustainable strategy to protect the harvest. However, most known leaf rust resistance genes have been overcome by the pathogen due to the pathogen's evolution and adaptation. The discovery of novel sources of genetic resistance is vital to keep fighting against pathogen evolution. In this study, we investigated the genetic basis of resistance in barley breeding line GID 5779743 (GID) from ICARDA, found to carry high levels of seedling resistance to prevalent Australian pathotypes of Puccinia hordei. Multipathotype tests, genotyping, and marker-trait associations revealed that the resistance in GID is conferred by two independent genes. The first gene, Rph3, was detected using a linked CAPS marker and QTL analysis. The second gene was detected by QTL analysis and mapped to the same location as that of the Rph5 locus on the telomeric region of chromosome 3HS. The segregating ratio in F2 (conforming to 9 resistant: 7 susceptible genetic ratio; p > 0.8) and F3 (1 resistant: 8 segregating: 7 susceptible; p > 0.19) generations of the GID × Gus population, when challenged with pathotype 5477 P- (virulent on Rph3 and Rph5) suggested the interaction of two genes in a complementary fashion. This study demonstrated that Rph3 interacts with Rph5 or an additional locus closely linked to Rph5 (tentatively designated RphGID) in GID to produce an incompatible response when challenged with a pathotype virulent on Rph3+Rph5.
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Affiliation(s)
- Hoan X. Dinh
- Faculty of Science, Plant Breeding Institute, The University of Sydney, Sydney, NSW, Australia
| | - Mohammad Pourkheirandish
- Faculty of Veterinary and Agricultural Sciences, The University of Melbourne, Parkville, VIC, Australia
| | - Robert F. Park
- Faculty of Science, Plant Breeding Institute, The University of Sydney, Sydney, NSW, Australia
| | - Davinder Singh
- Faculty of Science, Plant Breeding Institute, The University of Sydney, Sydney, NSW, Australia
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8
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Discovery and Chromosomal Location a Highly Effective Oat Crown Rust Resistance Gene Pc50-5. Int J Mol Sci 2021; 22:ijms222011183. [PMID: 34681841 PMCID: PMC8540790 DOI: 10.3390/ijms222011183] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2021] [Revised: 10/12/2021] [Accepted: 10/14/2021] [Indexed: 01/15/2023] Open
Abstract
Crown rust, caused by Puccinia coronata f. sp. avenae, is one of the most destructive fungal diseases of oat worldwide. Growing disease-resistant oat cultivars is the preferred method of preventing the spread of rust and potential epidemics. The object of the study was Pc50-5, a race-specific seedling crown rust resistant gene, highly effective at all growth stages, selected from the differential line Pc50 (Avena sterilis L. CW 486-1 × Pendek). A comparison of crown rust reaction as well as an allelism test showed the distinctiveness of Pc50-5, whereas the proportions of phenotypes in segregating populations derived from a cross with two crown rust-susceptible Polish oat cultivars, Kasztan × Pc50-5 and Bingo × Pc50-5, confirmed monogenic inheritance of the gene, indicating its usefulness in oat breeding programs. Effective gene introgression depends on reliable gene identification in the early stages of plant development; thus, the aim of the study was to develop molecular markers that are tightly linked to Pc50-5. Segregating populations of Kasztan × Pc50-5 were genotyped using DArTseq technology based on next-generation Illumina short-read sequencing. Markers associated with Pc50-5 were located on chromosome 6A of the current version of the oat reference genome (Avena sativa OT3098 v2, PepsiCo) in the region between 434,234,214 and 440,149,046 bp and subsequently converted to PCR-based SCAR (sequence-characterized amplified region) markers. Furthermore, 5426978_SCAR and 24031809_SCAR co-segregated with the Pc50-5 resistance allele and were mapped to the partial linkage group at 0.6 and 4.0 cM, respectively. The co-dominant 58163643_SCAR marker was the best diagnostic and it was located closest to Pc50-5 at 0.1 cM. The newly discovered, very strong monogenic crown rust resistance may be useful for oat improvement. DArTseq sequences converted into specific PCR markers will be a valuable tool for marker-assisted selection in breeding programs.
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9
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Maurer A, Pillen K. Footprints of Selection Derived From Temporal Heterozygosity Patterns in a Barley Nested Association Mapping Population. FRONTIERS IN PLANT SCIENCE 2021; 12:764537. [PMID: 34721490 PMCID: PMC8551860 DOI: 10.3389/fpls.2021.764537] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/25/2021] [Accepted: 09/22/2021] [Indexed: 06/13/2023]
Abstract
Nowadays, genetic diversity more than ever represents a key driver of adaptation to climate challenges like drought, heat, and salinity. Therefore, there is a need to replenish the limited elite gene pools with favorable exotic alleles from the wild progenitors of our crops. Nested association mapping (NAM) populations represent one step toward exotic allele evaluation and enrichment of the elite gene pool. We investigated an adaptive selection strategy in the wild barley NAM population HEB-25 based on temporal genomic data by studying the fate of 214,979 SNP loci initially heterozygous in individual BC1S3 lines after five cycles of selfing and field propagation. We identified several loci exposed to adaptive selection in HEB-25. In total, 48.7% (104,725 SNPs) of initially heterozygous SNP calls in HEB-25 were fixed in BC1S3:8 generation, either toward the wild allele (19.9%) or the cultivated allele (28.8%). Most fixed SNP loci turned out to represent gene loci involved in domestication and flowering time as well as plant height, for example, btr1/btr2, thresh-1, Ppd-H1, and sdw1. Interestingly, also unknown loci were found where the exotic allele was fixed, hinting at potentially useful exotic alleles for plant breeding.
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