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Dreisigacker S, Martini JWR, Cuevas J, Pérez-Rodríguez P, Lozano-Ramírez N, Huerta J, Singh P, Crespo-Herrera L, Bentley AR, Crossa J. Genomic prediction of synthetic hexaploid wheat upon tetraploid durum and diploid Aegilops parental pools. THE PLANT GENOME 2024; 17:e20464. [PMID: 38764312 DOI: 10.1002/tpg2.20464] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/30/2023] [Revised: 04/04/2024] [Accepted: 04/09/2024] [Indexed: 05/21/2024]
Abstract
Bread wheat (Triticum aestivum L.) is a globally important food crop, which was domesticated about 8-10,000 years ago. Bread wheat is an allopolyploid, and it evolved from two hybridization events of three species. To widen the genetic base in breeding, bread wheat has been re-synthesized by crossing durum wheat (Triticum turgidum ssp. durum) and goat grass (Aegilops tauschii Coss), leading to so-called synthetic hexaploid wheat (SHW). We applied the quantitative genetics tools of "hybrid prediction"-originally developed for the prediction of wheat hybrids generated from different heterotic groups - to a situation of allopolyploidization. Our use-case predicts the phenotypes of SHW for three quantitatively inherited global wheat diseases, namely tan spot (TS), septoria nodorum blotch (SNB), and spot blotch (SB). Our results revealed prediction abilities comparable to studies in 'traditional' elite or hybrid wheat. Prediction abilities were highest using a marker model and performing random cross-validation, predicting the performance of untested SHW (0.483 for SB to 0.730 for TS). When testing parents not necessarily used in SHW, combination prediction abilities were slightly lower (0.378 for SB to 0.718 for TS), yet still promising. Despite the limited phenotypic data, our results provide a general example for predictive models targeting an allopolyploidization event and a method that can guide the use of genetic resources available in gene banks.
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Affiliation(s)
| | | | - Jaime Cuevas
- Universidad Autónoma del Estado de Quintana Roo, Chetumal, México
| | | | | | - Julio Huerta
- International Maize and Wheat Improvement Center (CIMMYT), Texcoco, México
| | - Pawan Singh
- International Maize and Wheat Improvement Center (CIMMYT), Texcoco, México
| | | | - Alison R Bentley
- Australian National University, Research School of Biology, Canberra, Australia
| | - Jose Crossa
- International Maize and Wheat Improvement Center (CIMMYT), Texcoco, México
- Colegio de Postgraduados, Campus Montecillos, Texcoco, México
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Cuevas J, González-Diéguez D, Dreisigacker S, Martini JWR, Crespo-Herrera L, Lozano-Ramirez N, Singh PK, He X, Huerta J, Crossa J. Modeling within and between Sub-Genomes Epistasis of Synthetic Hexaploid Wheat for Genome-Enabled Prediction of Diseases. Genes (Basel) 2024; 15:262. [PMID: 38540321 PMCID: PMC10970072 DOI: 10.3390/genes15030262] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2024] [Revised: 02/12/2024] [Accepted: 02/18/2024] [Indexed: 06/15/2024] Open
Abstract
Common wheat (Triticum aestivum) is a hexaploid crop comprising three diploid sub-genomes labeled A, B, and D. The objective of this study is to investigate whether there is a discernible influence pattern from the D sub-genome with epistasis in genomic models for wheat diseases. Four genomic statistical models were employed; two models considered the linear genomic relationship of the lines. The first model (G) utilized all molecular markers, while the second model (ABD) utilized three matrices representing the A, B, and D sub-genomes. The remaining two models incorporated epistasis, one (GI) using all markers and the other (ABDI) considering markers in sub-genomes A, B, and D, including inter- and intra-sub-genome interactions. The data utilized pertained to three diseases: tan spot (TS), septoria nodorum blotch (SNB), and spot blotch (SB), for synthetic hexaploid wheat (SHW) lines. The results (variance components) indicate that epistasis makes a substantial contribution to explaining genomic variation, accounting for approximately 50% in SNB and SB and only 29% for TS. In this contribution of epistasis, the influence of intra- and inter-sub-genome interactions of the D sub-genome is crucial, being close to 50% in TS and higher in SNB (60%) and SB (60%). This increase in explaining genomic variation is reflected in an enhancement of predictive ability from the G model (additive) to the ABDI model (additive and epistasis) by 9%, 5%, and 1% for SNB, SB, and TS, respectively. These results, in line with other studies, underscore the significance of the D sub-genome in disease traits and suggest a potential application to be explored in the future regarding the selection of parental crosses based on sub-genomes.
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Affiliation(s)
- Jaime Cuevas
- Departamento de Energía, Universidad Autónoma del Estado de Quintana Roo, Chetumal 77019, Quintana Roo, Mexico;
| | - David González-Diéguez
- International Maize and Wheat Improvement Center (CIMMYT), Km. 45, Carretera México-Veracruz, Texcoco 56237, Edo. de México, Mexico; (D.G.-D.); (S.D.); (J.W.R.M.); (L.C.-H.); (P.K.S.); (X.H.); (J.H.)
| | - Susanne Dreisigacker
- International Maize and Wheat Improvement Center (CIMMYT), Km. 45, Carretera México-Veracruz, Texcoco 56237, Edo. de México, Mexico; (D.G.-D.); (S.D.); (J.W.R.M.); (L.C.-H.); (P.K.S.); (X.H.); (J.H.)
| | - Johannes W. R. Martini
- International Maize and Wheat Improvement Center (CIMMYT), Km. 45, Carretera México-Veracruz, Texcoco 56237, Edo. de México, Mexico; (D.G.-D.); (S.D.); (J.W.R.M.); (L.C.-H.); (P.K.S.); (X.H.); (J.H.)
| | - Leo Crespo-Herrera
- International Maize and Wheat Improvement Center (CIMMYT), Km. 45, Carretera México-Veracruz, Texcoco 56237, Edo. de México, Mexico; (D.G.-D.); (S.D.); (J.W.R.M.); (L.C.-H.); (P.K.S.); (X.H.); (J.H.)
| | - Nerida Lozano-Ramirez
- International Maize and Wheat Improvement Center (CIMMYT), Km. 45, Carretera México-Veracruz, Texcoco 56237, Edo. de México, Mexico; (D.G.-D.); (S.D.); (J.W.R.M.); (L.C.-H.); (P.K.S.); (X.H.); (J.H.)
| | - Pawan K. Singh
- International Maize and Wheat Improvement Center (CIMMYT), Km. 45, Carretera México-Veracruz, Texcoco 56237, Edo. de México, Mexico; (D.G.-D.); (S.D.); (J.W.R.M.); (L.C.-H.); (P.K.S.); (X.H.); (J.H.)
| | - Xinyao He
- International Maize and Wheat Improvement Center (CIMMYT), Km. 45, Carretera México-Veracruz, Texcoco 56237, Edo. de México, Mexico; (D.G.-D.); (S.D.); (J.W.R.M.); (L.C.-H.); (P.K.S.); (X.H.); (J.H.)
| | - Julio Huerta
- International Maize and Wheat Improvement Center (CIMMYT), Km. 45, Carretera México-Veracruz, Texcoco 56237, Edo. de México, Mexico; (D.G.-D.); (S.D.); (J.W.R.M.); (L.C.-H.); (P.K.S.); (X.H.); (J.H.)
| | - Jose Crossa
- International Maize and Wheat Improvement Center (CIMMYT), Km. 45, Carretera México-Veracruz, Texcoco 56237, Edo. de México, Mexico; (D.G.-D.); (S.D.); (J.W.R.M.); (L.C.-H.); (P.K.S.); (X.H.); (J.H.)
- Colegio de Postgraduados (COLPOS), Montecillos 56230, Edo. de México, Mexico
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Laribi M, Fredua-Agyeman R, Ben M’Barek S, Sansaloni CP, Dreisigacker S, Gamba FM, Abdedayem W, Nefzaoui M, Araar C, Hwang SF, Yahyaoui AH, Strelkov SE. Genome-wide association analysis of tan spot disease resistance in durum wheat accessions from Tunisia. Front Genet 2023; 14:1231027. [PMID: 37946749 PMCID: PMC10631785 DOI: 10.3389/fgene.2023.1231027] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2023] [Accepted: 10/02/2023] [Indexed: 11/12/2023] Open
Abstract
Background: Tunisia harbors a rich collection of unexploited durum wheat landraces (Triticum durum ssp. durum) that have been gradually replaced by elite cultivars since the 1970s. These landraces represent an important potential source for broadening the genetic background of elite durum wheat cultivars and for the introgression of novel genes for key traits, including disease resistance, into these cultivars. Methods: In this study, single nucleotide polymorphism (SNP) markers were used to investigate the genetic diversity and population structure of a core collection of 235 durum wheat accessions consisting mainly of landraces. The high phenotypic and genetic diversity of the fungal pathogen Pyrenophora tritici-repentis (cause of tan spot disease of wheat) in Tunisia allowed the assessment of the accessions for tan spot resistance at the adult plant stage under field conditions over three cropping seasons. A genome-wide association study (GWAS) was performed using a 90k SNP array. Results: Bayesian population structure analysis with 9191 polymorphic SNP markers classified the accessions into two groups, where groups 1 and 2 included 49.79% and 31.49% of the accessions, respectively, while the remaining 18.72% were admixtures. Principal coordinate analysis, the unweighted pair group method with arithmetic mean and the neighbor-joining method clustered the accessions into three to five groups. Analysis of molecular variance indicated that 76% of the genetic variation was among individuals and 23% was between individuals. Genome-wide association analyses identified 26 SNPs associated with tan spot resistance and explained between 8.1% to 20.2% of the phenotypic variation. The SNPs were located on chromosomes 1B (1 SNP), 2B (4 SNPs), 3A (2 SNPs), 3B (2 SNPs), 4A (2 SNPs), 4B (1 SNP), 5A (2 SNPs), 5B (4 SNPs), 6A (5 SNPs), 6B (2 SNPs), and 7B (1 SNP). Four markers, one on each of chromosomes 1B, and 5A, and two on 5B, coincided with previously reported SNPs for tan spot resistance, while the remaining SNPs were either novel markers or closely related to previously reported SNPs. Eight durum wheat accessions were identified as possible novel sources of tan spot resistance that could be introgressed into elite cultivars. Conclusion: The results highlighted the significance of chromosomes 2B, 5B, and 6A as genomic regions associated with tan spot resistance.
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Affiliation(s)
- Marwa Laribi
- CRP Wheat Septoria Precision Phenotyping Platform, Tunis, Tunisia
- Department of Agricultural, Food and Nutritional Science, University of Alberta, Edmonton, AB, Canada
| | - Rudolph Fredua-Agyeman
- Department of Agricultural, Food and Nutritional Science, University of Alberta, Edmonton, AB, Canada
| | - Sarrah Ben M’Barek
- CRP Wheat Septoria Precision Phenotyping Platform, Tunis, Tunisia
- Regional Field Crops Research Center of Beja (CRRGC), Beja, Tunisia
| | | | | | | | - Wided Abdedayem
- CRP Wheat Septoria Precision Phenotyping Platform, Tunis, Tunisia
| | - Meriem Nefzaoui
- CRP Wheat Septoria Precision Phenotyping Platform, Tunis, Tunisia
| | - Chayma Araar
- CRP Wheat Septoria Precision Phenotyping Platform, Tunis, Tunisia
| | - Sheau-Fang Hwang
- Department of Agricultural, Food and Nutritional Science, University of Alberta, Edmonton, AB, Canada
| | - Amor H. Yahyaoui
- CRP Wheat Septoria Precision Phenotyping Platform, Tunis, Tunisia
- Borlaug Training Foundation, Colorado State University, Fort Collins, CO, United States
| | - Stephen E. Strelkov
- Department of Agricultural, Food and Nutritional Science, University of Alberta, Edmonton, AB, Canada
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Navathe S, He X, Kamble U, Kumar M, Patial M, Singh G, Singh GP, Joshi AK, Singh PK. Assessment of Indian wheat germplasm for Septoria nodorum blotch and tan spot reveals new QTLs conferring resistance along with recessive alleles of Tsn1 and Snn3. FRONTIERS IN PLANT SCIENCE 2023; 14:1223959. [PMID: 37881616 PMCID: PMC10597639 DOI: 10.3389/fpls.2023.1223959] [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: 05/16/2023] [Accepted: 09/20/2023] [Indexed: 10/27/2023]
Abstract
The leaf blight diseases, Septoria nodorum blotch (SNB), and tan spot (TS) are emerging due to changing climatic conditions in the northern parts of India. We screened 296 bread wheat cultivars released in India over the past 20 years for seedling resistance against SNB (three experiments) and TS (two experiments). According to a genome-wide association study, six QTLs on chromosome arms 1BL, 2AS, 5BL, and 6BL were particularly significant for SNB across all three years, of which Q.CIM.snb.1BL, Q.CIM.snb.2AS1, Q.CIM.snb.2AS.2, and Q.CIM.snb.6BL appeared novel. In contrast, those on 5BS and 5BL may correspond to Snn3 and Tsn1, respectively. The allelic combination of tsn1/snn3 conferred resistance to SNB, whereas that of Tsn1/Snn3 conferred high susceptibility. As for TS, Tsn1 was the only stably significant locus identified in this panel. Several varieties like PBW 771, DBW 277, and HD 3319, were identified as highly resistant to both diseases that can be used in future wheat improvement programs as resistant donors.
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Affiliation(s)
- Sudhir Navathe
- Genetics and Plant Breeding Group, Agharkar Research Institute, Pune, India
| | - Xinyao He
- Global Wheat Program, International Maize and Wheat Improvement Centre (CIMMYT), Texcoco, Mexico
| | - Umesh Kamble
- Division of Crop Improvement, ICAR-Indian Institute of Wheat and Barley Research, Karnal, India
| | - Manjeet Kumar
- Division of Genetics, ICAR-Indian Agricultural Research Institute, New Delhi, India
| | - Madhu Patial
- Division of Genetics, ICAR-Indian Agricultural Research Institute, New Delhi, India
| | - Gyanendra Singh
- Division of Crop Improvement, ICAR-Indian Institute of Wheat and Barley Research, Karnal, India
| | - Gyanendra Pratap Singh
- Indian Council of Agricultural Research (ICAR)-National Bureau of Plant Genetic Resources, New Delhi, India
| | - Arun Kumar Joshi
- International Maize and Wheat Improvement Centre (CIMMYT) & Borlaug Institute for South Asia (BISA), New Delhi, India
| | - Pawan Kumar Singh
- Global Wheat Program, International Maize and Wheat Improvement Centre (CIMMYT), Texcoco, Mexico
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Peters Haugrud AR, Shi G, Seneviratne S, Running KLD, Zhang Z, Singh G, Szabo-Hever A, Acharya K, Friesen TL, Liu Z, Faris JD. Genome-wide association mapping of resistance to the foliar diseases septoria nodorum blotch and tan spot in a global winter wheat collection. MOLECULAR BREEDING : NEW STRATEGIES IN PLANT IMPROVEMENT 2023; 43:54. [PMID: 37337566 PMCID: PMC10276793 DOI: 10.1007/s11032-023-01400-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/07/2023] [Accepted: 06/02/2023] [Indexed: 06/21/2023]
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. Supplementary Information The online version contains supplementary material available at 10.1007/s11032-023-01400-5.
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Affiliation(s)
- Amanda R. Peters Haugrud
- Cereal Crops Research Unit, Edward T. Schafer Agricultural Research Center, Agricultural Research Service, United States Department of Agriculture, , Fargo, ND 58102 USA
| | - Gongjun Shi
- Department of Plant Pathology, North Dakota State University, Fargo, ND 58102 USA
| | - Sudeshi Seneviratne
- Department of Plant Sciences, North Dakota State University, Fargo, ND 58102 USA
| | | | - Zengcui Zhang
- Cereal Crops Research Unit, Edward T. Schafer Agricultural Research Center, Agricultural Research Service, United States Department of Agriculture, , Fargo, ND 58102 USA
| | - Gurminder Singh
- Department of Plant Sciences, North Dakota State University, Fargo, ND 58102 USA
| | - Agnes Szabo-Hever
- Cereal Crops Research Unit, Edward T. Schafer Agricultural Research Center, Agricultural Research Service, United States Department of Agriculture, , Fargo, ND 58102 USA
| | - Krishna Acharya
- Department of Plant Sciences, North Dakota State University, Fargo, ND 58102 USA
| | - Timothy L. Friesen
- Cereal Crops Research Unit, Edward T. Schafer Agricultural Research Center, Agricultural Research Service, United States Department of Agriculture, , Fargo, ND 58102 USA
| | - Zhaohui Liu
- Department of Plant Pathology, North Dakota State University, Fargo, ND 58102 USA
| | - Justin D. Faris
- Cereal Crops Research Unit, Edward T. Schafer Agricultural Research Center, Agricultural Research Service, United States Department of Agriculture, , Fargo, ND 58102 USA
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García-Barrios G, Crossa J, Cruz-Izquierdo S, Aguilar-Rincón VH, Sandoval-Islas JS, Corona-Torres T, Lozano-Ramírez N, Dreisigacker S, He X, Singh PK, Pacheco-Gil RA. Genomic Prediction of Resistance to Tan Spot, Spot Blotch and Septoria Nodorum Blotch in Synthetic Hexaploid Wheat. Int J Mol Sci 2023; 24:10506. [PMID: 37445683 DOI: 10.3390/ijms241310506] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2023] [Revised: 06/09/2023] [Accepted: 06/20/2023] [Indexed: 07/15/2023] Open
Abstract
Genomic prediction combines molecular and phenotypic data in a training population to predict the breeding values of individuals that have only been genotyped. The use of genomic information in breeding programs helps to increase the frequency of favorable alleles in the populations of interest. This study evaluated the performance of BLUP (Best Linear Unbiased Prediction) in predicting resistance to tan spot, spot blotch and Septoria nodorum blotch in synthetic hexaploid wheat. BLUP was implemented in single-trait and multi-trait models with three variations: (1) the pedigree relationship matrix (A-BLUP), (2) the genomic relationship matrix (G-BLUP), and (3) a combination of the two matrices (A+G BLUP). In all three diseases, the A-BLUP model had a lower performance, and the G-BLUP and A+G BLUP were statistically similar (p ≥ 0.05). The prediction accuracy with the single trait was statistically similar (p ≥ 0.05) to the multi-trait accuracy, possibly due to the low correlation of severity between the diseases.
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Affiliation(s)
- Guillermo García-Barrios
- Postgrado en Recursos Genéticos y Productividad-Genética, Colegio de Postgraduados, Campus Montecillo, Texcoco 56264, Estado de México, Mexico
| | - José Crossa
- International Maize and Wheat Improvement Center (CIMMYT), Km 35 Carretera México-Veracruz, Texcoco 56237, Estado de México, Mexico
- Postgrado en Socioeconomía, Estadística e Informática, Colegio de Postgraduados, Campus Montecillo, Texcoco 56264, Estado de México, Mexico
| | - Serafín Cruz-Izquierdo
- Postgrado en Recursos Genéticos y Productividad-Genética, Colegio de Postgraduados, Campus Montecillo, Texcoco 56264, Estado de México, Mexico
| | - Víctor Heber Aguilar-Rincón
- Postgrado en Recursos Genéticos y Productividad-Genética, Colegio de Postgraduados, Campus Montecillo, Texcoco 56264, Estado de México, Mexico
| | - J Sergio Sandoval-Islas
- Postgrado en Fitosanidad, Colegio de Postgraduados, Campus Montecillo, Texcoco 56264, Estado de México, Mexico
| | - Tarsicio Corona-Torres
- Postgrado en Recursos Genéticos y Productividad-Genética, Colegio de Postgraduados, Campus Montecillo, Texcoco 56264, Estado de México, Mexico
| | - Nerida Lozano-Ramírez
- International Maize and Wheat Improvement Center (CIMMYT), Km 35 Carretera México-Veracruz, Texcoco 56237, Estado de México, Mexico
| | - Susanne Dreisigacker
- International Maize and Wheat Improvement Center (CIMMYT), Km 35 Carretera México-Veracruz, Texcoco 56237, Estado de México, Mexico
| | - Xinyao He
- International Maize and Wheat Improvement Center (CIMMYT), Km 35 Carretera México-Veracruz, Texcoco 56237, Estado de México, Mexico
| | - Pawan Kumar Singh
- International Maize and Wheat Improvement Center (CIMMYT), Km 35 Carretera México-Veracruz, Texcoco 56237, Estado de México, Mexico
| | - Rosa Angela Pacheco-Gil
- International Maize and Wheat Improvement Center (CIMMYT), Km 35 Carretera México-Veracruz, Texcoco 56237, Estado de México, Mexico
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7
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Taylor J, Jorgensen D, Moffat CS, Chalmers KJ, Fox R, Hollaway GJ, Cook MJ, Neate SM, See PT, Shankar M. An international wheat diversity panel reveals novel sources of genetic resistance to tan spot in Australia. TAG. THEORETICAL AND APPLIED GENETICS. THEORETISCHE UND ANGEWANDTE GENETIK 2023; 136:61. [PMID: 36912976 PMCID: PMC10011302 DOI: 10.1007/s00122-023-04332-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/18/2022] [Accepted: 02/23/2023] [Indexed: 06/18/2023]
Abstract
Novel sources of genetic resistance to tan spot in Australia have been discovered using one-step GWAS and genomic prediction models that accounts for additive and non-additive genetic variation. Tan spot is a foliar disease in wheat caused by the fungal pathogen Pyrenophora tritici-repentis (Ptr) and has been reported to generate up to 50% yield losses under favourable disease conditions. Although farming management practices are available to reduce disease, the most economically sustainable approach is establishing genetic resistance through plant breeding. To further understand the genetic basis for disease resistance, we conducted a phenotypic and genetic analysis study using an international diversity panel of 192 wheat lines from the Maize and Wheat Improvement Centre (CIMMYT), the International Centre for Agriculture in the Dry Areas (ICARDA) and Australian (AUS) wheat research programmes. The panel was evaluated using Australian Ptr isolates in 12 experiments conducted in three Australian locations over two years, with assessment for tan spot symptoms at various plant development stages. Phenotypic modelling indicated high heritability for nearly all tan spot traits with ICARDA lines displaying the greatest average resistance. We then conducted a one-step whole-genome analysis of each trait using a high-density SNP array, revealing a large number of highly significant QTL exhibiting a distinct lack of repeatability across the traits. To better summarise the genetic resistance of the lines, a one-step genomic prediction of each tan spot trait was conducted by combining the additive and non-additive predicted genetic effects of the lines. This revealed multiple CIMMYT lines with broad genetic resistance across the developmental stages of the plant which can be utilised in Australian wheat breeding programmes to improve tan spot disease resistance.
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Affiliation(s)
- Julian Taylor
- School of Agriculture, Food and Wine, Waite Research Institute, University of Adelaide, Glen Osmond, SA, 5064, Australia.
| | - Dorthe Jorgensen
- Department of Primary Industries and Regional Development, Agriculture and Food, 3 Baron Hay Ct, South Perth, WA, 6151, Australia
| | - Caroline S Moffat
- Centre for Crop Disease and Management, School of Molecular and Life Sciences, Curtin University, Kent St, Bentley, WA, 6102, Australia
| | - Ken J Chalmers
- School of Agriculture, Food and Wine, Waite Research Institute, University of Adelaide, Glen Osmond, SA, 5064, Australia
| | - Rebecca Fox
- School of Agriculture, Food and Wine, Waite Research Institute, University of Adelaide, Glen Osmond, SA, 5064, Australia
| | - Grant J Hollaway
- Agriculture Victoria, Private Bag 260, Horsham, VIC, 3401, Australia
| | - Melissa J Cook
- Agriculture Victoria, Private Bag 260, Horsham, VIC, 3401, Australia
| | - Stephen M Neate
- Centre for Crop Health, University of Southern Queensland, Toowoomba, QLD, 4350, Australia
| | - Pao Theen See
- Centre for Crop Disease and Management, School of Molecular and Life Sciences, Curtin University, Kent St, Bentley, WA, 6102, Australia
| | - Manisha Shankar
- Department of Primary Industries and Regional Development, Agriculture and Food, 3 Baron Hay Ct, South Perth, WA, 6151, Australia.
- School of Agriculture and Environment, University of Western Australia, 35 Stirling Hwy, Crawley, WA, 6009, Australia.
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8
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Genome-Wide Association Study for Spot Blotch Resistance in Synthetic Hexaploid Wheat. Genes (Basel) 2022; 13:genes13081387. [PMID: 36011298 PMCID: PMC9407756 DOI: 10.3390/genes13081387] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2022] [Revised: 07/20/2022] [Accepted: 07/22/2022] [Indexed: 12/04/2022] Open
Abstract
Spot blotch (SB) caused by Bipolaris sorokiniana (Sacc.) Shoem is a destructive fungal disease affecting wheat and many other crops. Synthetic hexaploid wheat (SHW) offers opportunities to explore new resistance genes for SB for introgression into elite bread wheat. The objectives of our study were to evaluate a collection of 441 SHWs for resistance to SB and to identify potential new genomic regions associated with the disease. The panel exhibited high SB resistance, with 250 accessions showing resistance and 161 showing moderate resistance reactions. A genome-wide association study (GWAS) revealed a total of 41 significant marker–trait associations for resistance to SB, being located on chromosomes 1B, 1D, 2A, 2B, 2D, 3A, 3B, 3D, 4A, 4D, 5A, 5D, 6D, 7A, and 7D; yet none of them exhibited a major phenotypic effect. In addition, a partial least squares regression was conducted to validate the marker–trait associations, and 15 markers were found to be most important for SB resistance in the panel. To our knowledge, this is the first GWAS to investigate SB resistance in SHW that identified markers and resistant SHW lines to be utilized in wheat breeding.
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