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Kaur R, Vasistha NK, Ravat VK, Mishra VK, Sharma S, Joshi AK, Dhariwal R. Genome-Wide Association Study Reveals Novel Powdery Mildew Resistance Loci in Bread Wheat. PLANTS (BASEL, SWITZERLAND) 2023; 12:3864. [PMID: 38005757 PMCID: PMC10675159 DOI: 10.3390/plants12223864] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/28/2023] [Revised: 10/24/2023] [Accepted: 10/26/2023] [Indexed: 11/26/2023]
Abstract
Powdery mildew (PM), caused by the fungal pathogen Blumeria graminis f. sp. tritici (Bgt), significantly threatens global bread wheat production. Although the use of resistant cultivars is an effective strategy for managing PM, currently available wheat cultivars lack sufficient levels of resistance. To tackle this challenge, we conducted a comprehensive genome-wide association study (GWAS) using a diverse panel of 286 bread wheat genotypes. Over three consecutive years (2020-2021, 2021-2022, and 2022-2023), these genotypes were extensively evaluated for PM severity under field conditions following inoculation with virulent Bgt isolates. The panel was previously genotyped using the Illumina 90K Infinium iSelect assay to obtain genome-wide single-nucleotide polymorphism (SNP) marker coverage. By applying FarmCPU, a multilocus mixed model, we identified a total of 113 marker-trait associations (MTAs) located on chromosomes 1A, 1B, 2B, 3A, 3B, 4A, 4B, 5A, 5B, 6B, 7A, and 7B at a significance level of p ≤ 0.001. Notably, four novel MTAs on chromosome 6B were consistently detected in 2020-2021 and 2021-2022. Furthermore, within the confidence intervals of the identified SNPs, we identified 96 candidate genes belonging to different proteins including 12 disease resistance/host-pathogen interaction-related protein families. Among these, protein kinases, leucine-rich repeats, and zinc finger proteins were of particular interest due to their potential roles in PM resistance. These identified loci can serve as targets for breeding programs aimed at developing disease-resistant wheat cultivars.
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Affiliation(s)
- Ramandeep Kaur
- Department of Genetics-Plant Breeding and Biotechnology, Dr. Khem Sigh Gill Akal College of Agriculture, Eternal University, Baru Sahib, Sirmour 173101, India
| | - Neeraj Kumar Vasistha
- Department of Genetics-Plant Breeding and Biotechnology, Dr. Khem Sigh Gill Akal College of Agriculture, Eternal University, Baru Sahib, Sirmour 173101, India
- Department of Genetics and Plant Breeding, Rajiv Gandhi University, Rono Hills, Itanagar 791112, India
| | - Vikas Kumar Ravat
- Department of Plant Pathology, Rajiv Gandhi University, Rono Hills, Itanagar 791112, India
| | - Vinod Kumar Mishra
- Department of Genetics and Plant Breeding, Institute of Agricultural Sciences, Banaras Hindu University, Varanasi 221005, India
| | - Sandeep Sharma
- Department of Genetics and Plant Breeding, Institute of Agricultural Sciences, Banaras Hindu University, Varanasi 221005, India
| | - Arun Kumar Joshi
- Borlaug Institute for South Asia (BISA), NASC Complex, DPS Marg, New Delhi 110012, India
- International Maize and Wheat Improvement Center (CIMMYT) Regional Office, NASC Complex, DPS Marg, New Delhi 110012, India
| | - Raman Dhariwal
- Agriculture and Agri-Food Canada, Lethbridge Research and Development Centre, 5403 1 Avenue South, Lethbridge, AB T1J 4B1, Canada
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Hinterberger V, Douchkov D, Lück S, Kale S, Mascher M, Stein N, Reif JC, Schulthess AW. Mining for New Sources of Resistance to Powdery Mildew in Genetic Resources of Winter Wheat. FRONTIERS IN PLANT SCIENCE 2022; 13:836723. [PMID: 35300015 PMCID: PMC8922026 DOI: 10.3389/fpls.2022.836723] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/15/2021] [Accepted: 01/31/2022] [Indexed: 05/02/2023]
Abstract
Genetic pathogen control is an economical and sustainable alternative to the use of chemicals. In order to breed resistant varieties, information about potentially unused genetic resistance mechanisms is of high value. We phenotyped 8,316 genotypes of the winter wheat collection of the German Federal ex situ gene bank for Agricultural and Horticultural Crops, Germany, for resistance to powdery mildew (PM), Blumeria graminis f. sp. tritici, one of the most important biotrophic pathogens in wheat. To achieve this, we used a semi-automatic phenotyping facility to perform high-throughput detached leaf assays. This data set, combined with genotyping-by-sequencing (GBS) marker data, was used to perform a genome-wide association study (GWAS). Alleles of significantly associated markers were compared with SNP profiles of 171 widely grown wheat varieties in Germany to identify currently unexploited resistance conferring genes. We also used the Chinese Spring reference genome annotation and various domain prediction algorithms to perform a domain enrichment analysis and produced a list of candidate genes for further investigation. We identified 51 significantly associated regions. In most of these, the susceptible allele was fixed in the tested commonly grown wheat varieties. Eleven of these were located on chromosomes for which no resistance conferring genes have been previously reported. In addition to enrichment of leucine-rich repeats (LRR), we saw enrichment of several domain types so far not reported as relevant to PM resistance, thus, indicating potentially novel candidate genes for the disease resistance research and prebreeding in wheat.
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Affiliation(s)
| | - Dimitar Douchkov
- Leibniz Institute of Plant Genetics and Crop Plant Research (IPK), Seeland, Germany
| | - Stefanie Lück
- Leibniz Institute of Plant Genetics and Crop Plant Research (IPK), Seeland, Germany
| | - Sandip Kale
- Leibniz Institute of Plant Genetics and Crop Plant Research (IPK), Seeland, Germany
| | - Martin Mascher
- Leibniz Institute of Plant Genetics and Crop Plant Research (IPK), Seeland, Germany
- German Centre for Integrative Biodiversity Research (iDiv) Halle-Jena-Leipzig, Leipzig, Germany
| | - Nils Stein
- Leibniz Institute of Plant Genetics and Crop Plant Research (IPK), Seeland, Germany
- Center for Integrated Breeding Research (CiBreed), Georg-August-University, Göttingen, Germany
| | - Jochen C. Reif
- Leibniz Institute of Plant Genetics and Crop Plant Research (IPK), Seeland, Germany
| | - Albert W. Schulthess
- Leibniz Institute of Plant Genetics and Crop Plant Research (IPK), Seeland, Germany
- *Correspondence: Albert W. Schulthess
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Mapping Powdery Mildew ( Blumeria graminis f. sp. tritici) Resistance in Wild and Cultivated Tetraploid Wheats. Int J Mol Sci 2020; 21:ijms21217910. [PMID: 33114422 PMCID: PMC7662567 DOI: 10.3390/ijms21217910] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2020] [Revised: 10/19/2020] [Accepted: 10/20/2020] [Indexed: 01/22/2023] Open
Abstract
Wheat is the most widely grown crop and represents the staple food for one third of the world’s population. Wheat is attacked by a large variety of pathogens and the use of resistant cultivars is an effective and environmentally safe strategy for controlling diseases and eliminating the use of fungicides. In this study, a collection of wild and cultivated tetraploid wheats (Triticum turgidum) were evaluated for seedling resistance (SR) and adult plant resistance (APR) to powdery mildew (Blumeria graminis) and genotyped with a 90K single nucleotide polymorphism (SNP) array to identify new sources of resistance genes. The genome-wide association mapping detected 18 quantitative trait loci (QTL) for APR and 8 QTL for SR, four of which were identical or at least closely linked to four QTL for APR. Thirteen candidate genes, containing nucleotide binding sites and leucine-rich repeats, were localized in the confidence intervals of the QTL-tagging SNPs. The marker IWB6155, associated to QPm.mgb-1AS, was located within the gene TRITD1Av1G004560 coding for a disease resistance protein. While most of the identified QTL were described previously, five QTL for APR (QPm.mgb-1AS, QPm.mgb-2BS, QPm.mgb-3BL.1, QPm.mgb-4BL, QPm.mgb-7BS.1) and three QTL for SR (QPm.mgb-3BL.3, QPm.mgb-5AL.2, QPm.mgb-7BS.2) were mapped on chromosome regions where no resistance gene was reported before. The novel QTL/genes can contribute to enriching the resistance sources available to breeders.
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Li Y, Shi X, Hu J, Wu P, Qiu D, Qu Y, Xie J, Wu Q, Zhang H, Yang L, Liu H, Zhou Y, Liu Z, Li H. Identification of a Recessive Gene PmQ Conferring Resistance to Powdery Mildew in Wheat Landrace Qingxinmai Using BSR-Seq Analysis. PLANT DISEASE 2020; 104:743-751. [PMID: 31967507 DOI: 10.1094/pdis-08-19-1745-re] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/07/2023]
Abstract
Wheat powdery mildew is caused by Blumeria graminis f. sp. tritici (Bgt), a biotrophic fungal species. It is very important to mine new powdery mildew (Pm) resistance genes for developing resistant wheat cultivars to reduce the deleterious effects of the disease. This study was carried out to characterize the Pm gene in Qingxinmai, a winter wheat landrace from Xinjiang, China. Qingxinmai is resistant to many Bgt isolates collected from different wheat fields in China. F1, F2, and F2:3 generations of the cross between Qingxinmai and powdery mildew susceptible line 041133 were developed. It was confirmed that a single recessive gene, PmQ, conferred the seedling resistance to a Bgt isolate in Qingxinmai. Bulked segregant analysis-RNA-Seq (BSR-Seq) was performed on the bulked homozygous resistant and susceptible F2:3 families, which detected 57 single nucleotide polymorphism (SNP) variants that were enriched in a 40 Mb genomic interval on chromosome arm 2BL. Based on the flanking sequences of the candidate SNPs extracted from the Chinese Spring reference genome, 485 simple sequence repeat (SSR) markers were designed. Six polymorphic SSR markers, together with nine markers that were anchored on chromosome arm 2BL, were used to construct a genetic linkage map for PmQ. This gene was placed in a 1.4 cM genetic interval between markers Xicsq405 and WGGBH913 corresponding to 4.9 Mb physical region in the Chinese Spring reference genome. PmQ differed from most of the other Pm genes identified on chromosome arm 2BL based on its position and/or origin. However, this gene and Pm63 from an Iranian common wheat landrace were located in a similar genomic region, so they may be allelic.
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Affiliation(s)
- Yahui Li
- The National Engineering Laboratory of Crop Molecular Breeding, Institute of Crop Sciences, Chinese Academy of Agricultural Sciences, Beijing 100081, China
| | - Xiaohan Shi
- The National Engineering Laboratory of Crop Molecular Breeding, Institute of Crop Sciences, Chinese Academy of Agricultural Sciences, Beijing 100081, China
| | - Jinghuang Hu
- The National Engineering Laboratory of Crop Molecular Breeding, Institute of Crop Sciences, Chinese Academy of Agricultural Sciences, Beijing 100081, China
| | - Peipei Wu
- The National Engineering Laboratory of Crop Molecular Breeding, Institute of Crop Sciences, Chinese Academy of Agricultural Sciences, Beijing 100081, China
| | - Dan Qiu
- The National Engineering Laboratory of Crop Molecular Breeding, Institute of Crop Sciences, Chinese Academy of Agricultural Sciences, Beijing 100081, China
| | - Yunfeng Qu
- The National Engineering Laboratory of Crop Molecular Breeding, Institute of Crop Sciences, Chinese Academy of Agricultural Sciences, Beijing 100081, China
| | - Jingzhong Xie
- Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China
| | - Qiuhong Wu
- Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China
| | - Hongjun Zhang
- The National Engineering Laboratory of Crop Molecular Breeding, Institute of Crop Sciences, Chinese Academy of Agricultural Sciences, Beijing 100081, China
| | - Li Yang
- The National Engineering Laboratory of Crop Molecular Breeding, Institute of Crop Sciences, Chinese Academy of Agricultural Sciences, Beijing 100081, China
| | - Hongwei Liu
- The National Engineering Laboratory of Crop Molecular Breeding, Institute of Crop Sciences, Chinese Academy of Agricultural Sciences, Beijing 100081, China
| | - Yang Zhou
- The National Engineering Laboratory of Crop Molecular Breeding, Institute of Crop Sciences, Chinese Academy of Agricultural Sciences, Beijing 100081, China
| | - Zhiyong Liu
- Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China
| | - Hongjie Li
- The National Engineering Laboratory of Crop Molecular Breeding, Institute of Crop Sciences, Chinese Academy of Agricultural Sciences, Beijing 100081, China
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Li H, Dong Z, Ma C, Tian X, Xiang Z, Xia Q, Ma P, Liu W. Discovery of powdery mildew resistance gene candidates from Aegilops biuncialis chromosome 2Mb based on transcriptome sequencing. PLoS One 2019; 14:e0220089. [PMID: 31710598 PMCID: PMC6844473 DOI: 10.1371/journal.pone.0220089] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2019] [Accepted: 10/23/2019] [Indexed: 01/07/2023] Open
Abstract
Powdery mildew is one of the most widespread diseases of wheat. The development and deployment of resistant varieties are one of the most economical and effective methods to manage this disease. Our previous study showed that the gene(s) at 2Mb in Chinese Spring (CS)-Aegilops biuncialis 2Mb disomic addition line TA7733 conferred a high level of resistance to powdery mildew of wheat. In this study, resistance spectrum of TA7733 was assayed by using 15 Blumeria graminis f. sp. tritici (Bgt) isolates prevalent in different regions of China. The result indicated that TA7733 was highly resistant to all tested Bgt isolates and the gene(s) on chromosome 2Mb conferred broad-spectrum resistance to powdery mildew. In order to characterize mechanism of powdery mildew resistance by identifying candidates R-genes derived from Ae. biuncialis chromosome 2Mb and develop 2Mb-specific molecular markers, we performed RNA-seq analysis on TA7733 and CS. In total we identified 7,278 unigenes that showed specific expression in TA7733 pre and post Bgt-infection when compared to CS. Of these 7,278 unigenes, 295 were annotated as putative resistance (R) genes. Comparatively analysis of R-gene sequences from TA7733 and CS and integration CS Ref Seq v1.0 were used to develop R-gene specific primers. Of 295 R-genes we identified 53 R-genes were specific to 2Mb and could be involved in powdery mildew resistance. Functional annotation of majority of the 53 R-genes encoded nucleotide binding leucine rich repeat (NLR) protein. The broad-spectrum resistance to powdery mildew in TA7733 and availability of 2Mb-derived putative candidate R-gene specific molecular markers identified in this study will lay foundations for transferring powdery mildew resistance from 2Mb to common wheat by inducing CS-Ae. biuncialis homoeologous recombination. Our study also provides useful candidates for further isolation and cloning of powdery mildew resistance gene(s) from Ae. biuncialis chromosome 2Mb.
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Affiliation(s)
- Huanhuan Li
- College of Life Sciences, Henan Agricultural University, Zhengzhou, Henan Province, China
| | - Zhenjie Dong
- College of Life Sciences, Henan Agricultural University, Zhengzhou, Henan Province, China
| | - Chao Ma
- College of Life Sciences, Henan Agricultural University, Zhengzhou, Henan Province, China
| | - Xiubin Tian
- College of Life Sciences, Henan Agricultural University, Zhengzhou, Henan Province, China
| | - Zhiguo Xiang
- Wheat Research Center, Henan Academy of Agricultural Sciences, Zhengzhou, Henan Province, China
| | - Qing Xia
- College of Life Sciences, Henan Agricultural University, Zhengzhou, Henan Province, China
| | - Pengtao Ma
- College of Life Sciences, Yantai University, Yantai, Shandong Province, China
| | - Wenxuan Liu
- College of Life Sciences, Henan Agricultural University, Zhengzhou, Henan Province, China
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Qie Y, Sheng Y, Xu H, Jin Y, Ma F, Li L, Li X, An D. Identification of a New Powdery Mildew Resistance Gene pmDHT at or Closely Linked to the Pm5 Locus in the Chinese Wheat Landrace Dahongtou. PLANT DISEASE 2019; 103:2645-2651. [PMID: 31453747 DOI: 10.1094/pdis-02-19-0401-re] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
Chinese wheat landrace Dahongtou was resistant to 35 of 38 tested Chinese isolates of Blumeria graminis f. sp. tritici at the seedling stage. Genetic analysis of the F2 populations and their derived F2:3 families of crosses of Dahongtou with the susceptible varieties Mingxian 169 and Huixianhong indicated that the resistance of Dahongtou to B. graminis f. sp. tritici isolate E09 was conferred by a single recessive gene, tentatively designated as pmDHT. The gene was mapped to chromosome arm 7BL and flanked by markers Xwmc526/XBE443877 and Xgwm611/Xwmc511 at genetic distances of 0.8 and 0.3 cM, respectively. The chromosomal position of pmDHT was similar to the multi-allelic Pm5 locus on 7BL. Allelism tests with crosses of Dahongtou with Fuzhuang 30 (Pm5e) and Xiaobaidong (mlxbd) indicated that pmDHT was allelic to both Pm5e and mlxbd. However, pmDHT showed a different pattern of resistance to the 38 B. graminis f. sp. tritici isolates compared with wheat lines with Pm5a, Pm5b, Pm5e, mlxbd, and PmHYM and also differed from PmSGA. Thus, pmDHT was identified most likely as a new allele or at least a closely linked gene of the Pm5 locus. This gene can be transferred into susceptible wheat cultivars/lines and pyramided with other resistance genes through marker-assisted selection to improve powdery mildew resistance.
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Affiliation(s)
- Yanmin Qie
- Center for Agricultural Resources Research, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Shijiazhuang, Hebei 050021, China
| | - Yuan Sheng
- Center for Agricultural Resources Research, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Shijiazhuang, Hebei 050021, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Hongxing Xu
- Center for Agricultural Resources Research, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Shijiazhuang, Hebei 050021, China
| | - Yuli Jin
- Center for Agricultural Resources Research, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Shijiazhuang, Hebei 050021, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Feifei Ma
- Center for Agricultural Resources Research, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Shijiazhuang, Hebei 050021, China
| | - Lihui Li
- National Key Facility for Crop Gene Resources and Genetic Improvement, Institute of Crop Science, Chinese Academy of Agricultural Sciences, Beijing 100081, China
| | - Xiuquan Li
- National Key Facility for Crop Gene Resources and Genetic Improvement, Institute of Crop Science, Chinese Academy of Agricultural Sciences, Beijing 100081, China
| | - Diaoguo An
- Center for Agricultural Resources Research, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Shijiazhuang, Hebei 050021, China
- The Innovative Academy of Seed Design, Chinese Academy of Sciences, Beijing, China
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Li G, Cowger C, Wang X, Carver BF, Xu X. Characterization of Pm65, a new powdery mildew resistance gene on chromosome 2AL of a facultative wheat cultivar. TAG. THEORETICAL AND APPLIED GENETICS. THEORETISCHE UND ANGEWANDTE GENETIK 2019; 132:2625-2632. [PMID: 31214740 DOI: 10.1007/s00122-019-03377-2] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/09/2019] [Accepted: 06/09/2019] [Indexed: 05/18/2023]
Abstract
A new powdery mildew resistance gene that can be readily used in wheat breeding, Pm65, was identified in the facultative wheat cultivar Xinmai 208 and mapped to the terminal region of chromosome 2AL. Wheat powdery mildew, a widely occurring disease caused by the biotrophic fungus Blumeriagraminis f. sp. tritici (Bgt), poses a serious threat to wheat production. A high breeding priority is to identify powdery mildew resistance genes that can be readily used either alone or in gene complexes involving other disease resistance genes. An F2 population and 227 F2:3 families derived from the cross Xinmai 208 × Stardust were generated to map a powdery mildew resistance gene in Xinmai 208, a high-yielding Chinese wheat cultivar. Genetic analysis indicated that Xinmai 208 carries a single dominant powdery mildew resistance gene, designated herein Pm65, and linkage analysis delimited Pm65 to a 0.5 cM interval covering 531.8 Kb (763,289,667-763,821,463 bp) on chromosome 2AL in the Chinese Spring reference sequence. An allelism test indicated that Pm65 is a new gene about 10.3 cM distal to the Pm4 locus. Pm65 was 0.3 cM proximal to Xstars355 and 0.2 cM distal to Xstars356. It conferred near-immunity to 19 of 20 Bgt isolates collected from different wheat-growing regions of the USA. Coming from a high-yield potential cultivar, Pm65 can be directly used to enhance powdery mildew resistance in wheat. The newly developed SSR markers Xstars355 and Xstars356 have the potential to tag Pm65 for wheat improvement.
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Affiliation(s)
- Genqiao Li
- Wheat, Peanut, and Other Field Crops Research Unit, USDA-ARS, Stillwater, OK, 74075, USA
- Plant and Soil Science Department, Oklahoma State University, Stillwater, OK, 74078, USA
| | | | - Xuewen Wang
- Genetics Department, The University of Georgia, Athens, GA, 30602, USA
| | - Brett F Carver
- Plant and Soil Science Department, Oklahoma State University, Stillwater, OK, 74078, USA
| | - Xiangyang Xu
- Wheat, Peanut, and Other Field Crops Research Unit, USDA-ARS, Stillwater, OK, 74075, USA.
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Genetic Dissection of Resistance to the Three Fungal Plant Pathogens Blumeria graminis, Zymoseptoria tritici, and Pyrenophora tritici-repentis Using a Multiparental Winter Wheat Population. G3-GENES GENOMES GENETICS 2019; 9:1745-1757. [PMID: 30902891 PMCID: PMC6505172 DOI: 10.1534/g3.119.400068] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Bread wheat (Triticum aestivum L.) is one of the world’s most important crop species. The development of new varieties resistant to multiple pathogens is an ongoing task in wheat breeding, especially in times of increasing demand for sustainable agricultural practices. Despite this, little is known about the relations between various fungal disease resistances at the genetic level, and the possible consequences for wheat breeding strategies. As a first step to fill this gap, we analyzed the genetic relations of resistance to the three fungal diseases – powdery mildew (PM), septoria tritici blotch (STB), and tan spot (TS) – using a winter wheat multiparent advanced generation intercross population. Six, seven, and nine QTL for resistance to PM, STB, and TS, respectively, were genetically mapped. Additionally, 15 QTL were identified for the three agro-morphological traits plant height, ear emergence time, and leaf angle distribution. Our results suggest that resistance to STB and TS on chromosome 2B is conferred by the same genetic region. Furthermore, we identified two genetic regions on chromosome 1AS and 7AL, which are associated with all three diseases, but not always in a synchronal manner. Based on our results, we conclude that parallel marker-assisted breeding for resistance to the fungal diseases PM, STB, and TS appears feasible. Knowledge of the genetic co-localization of alleles with contrasting effects for different diseases, such as on chromosome 7AL, allows the trade-offs of selection of these regions to be better understood, and ultimately determined at the genic level.
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Development of SNP, KASP, and SSR Markers by BSR-Seq Technology for Saturation of Genetic Linkage Map and Efficient Detection of Wheat Powdery Mildew Resistance Gene Pm61. Int J Mol Sci 2019; 20:ijms20030750. [PMID: 30754626 PMCID: PMC6387370 DOI: 10.3390/ijms20030750] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2018] [Accepted: 01/29/2019] [Indexed: 11/17/2022] Open
Abstract
The gene Pm61 that confers powdery mildew resistance has been previously identified on chromosome arm 4AL in Chinese wheat landrace Xuxusanyuehuang (XXSYH). To facilitate the use of Pm61 in breeding practices, the bulked segregant analysis-RNA-Seq (BSR-Seq) analysis, in combination with the information on the Chinese Spring reference genome sequence, was performed in the F2:3 mapping population of XXSYH × Zhongzuo 9504. Two single nucleotide polymorphism (SNP), two Kompetitive Allele Specific PCR (KASP), and six simple sequence repeat (SSR) markers, together with previously identified polymorphic markers, saturated the genetic linkage map for Pm61, especially in the proximal side of the target gene that was short of gene-linked markers. In the newly established genetic linkage map, Pm61 was located in a 0.71 cM genetic interval and can be detected in a high throughput scale by the KASP markers Xicsk8 and Xicsk13 or by the standard PCR-based markers Xicscx497 and Xicsx538. The newly saturated genetic linkage map will be useful in molecular marker assisted-selection of Pm61 in breeding for disease resistant cultivar and in its map-based cloning.
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Dong J, Xu J, Xu X, Xu Q, Chen X. Inheritance and Quantitative Trait Locus Mapping of Fusarium Wilt Resistance in Cucumber. FRONTIERS IN PLANT SCIENCE 2019; 10:1425. [PMID: 31850001 PMCID: PMC6900741 DOI: 10.3389/fpls.2019.01425] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/14/2019] [Accepted: 10/14/2019] [Indexed: 05/15/2023]
Abstract
Fusarium wilt (FW) is a very serious soil-borne disease worldwide, which usually results in huge yield losses in cucumber production. However, the inheritance and molecular mechanism of the response to FW are still unknown in cucumber (Cucumis sativus L.). In this study, two inbred cucumber lines Superina (P1) and Rijiecheng (P2) were used as the sensitive and resistant lines, respectively. A mixed major gene plus polygene inheritance model was used to analyze the resistance to FW in different generations of cucumber, namely, P1, P2, F1 (P1×P2), B1, and B2, obtained by backcrossing F1 plants with Superina (B1) or Rijiecheng (B2), and F2, obtained by self-crossing the F1 plants. After screening 18 genetic models, we chose the E-1 model, which included two pairs of additive-dominance-epistatic major genes and additive-dominance polygenes, as the optimal model for resistance to FW on the basis of fitness tests. The major effect quantitative trait locus (QTL) fw2.1 was detected in a 1.91-Mb-long region of chromosome 2 by bulked-segregant analysis. We used five insertion/deletion markers to fine-map the fw2.1 to a 0.60 Mb interval from 1,248,093 to 1,817,308 bp on chromosome 2 that contained 80 candidate genes. We also used the transcriptome data of Rijiecheng inoculated with Fusarium oxysporum f. sp. cucumerinum (Foc) to screen the candidate genes. Twelve differentially expressed genes were detected in fw2.1, and five of them were significantly induced by FW. The expression levels of the five genes were higher in FW-resistant Rijiecheng inoculated with Foc than in the control inoculated with water. Our results will contribute to a better understanding of the genetic basis of FW resistance in cucumber, which may help in breeding FW-resistant cucumber lines in the future.
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