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Khurshid K, Akram A, Ali A, Munir F, Gul A, Haider G, Qayyum Z, Amir R. Genome wide identification and characterization of nodulation related genes in Arachis hypogaea. PLoS One 2022; 17:e0273768. [PMID: 36084097 PMCID: PMC9462762 DOI: 10.1371/journal.pone.0273768] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2022] [Accepted: 08/16/2022] [Indexed: 11/18/2022] Open
Abstract
Nitrogen is an important plant nutrient that has a significant role in crop yield. Hence, to fulfill the needs of sustainable agriculture, it is necessary to improve biological nitrogen fixation in leguminous crops. Nod inducing gene families plays a crucial role in the interaction between rhizobia and legumes, leading to biological nitrogen fixation. However, nod inducing genes identification and characterization has not yet been performed in Arachis hypogaea. In this study, identification and genome-wide analysis of nod inducing genes are performed so that to explore their potential functions in the Arachis hypogaea for the first time. Nod genes were comprehensively analyzed by phylogenetic clustering analysis, gene structure determination, detection of conserved motifs, subcellular localization, conserved motifs, cis-acting elements and promoter region analysis. This study identified 42 Nod inducing genes in Arachis hypogaea, their sequences were submitted to NCBI and accession numbers were obtained. Potential involvement of these genes in biological nitrogen fixation has been unraveled, such as, phylogenetic analysis revealed that nod inducing genes evolved independently in Arachis hypogaea, the amino acid structures exhibited 20 highly conserved motifs, the proteins are present at different locations in cells and the gene structures revealed that all the genes are full-length genes with upstream intronic regions. Further, the promoter analysis determined a large number of cis-regulatory elements involved in nodulation. Moreover, this study not only provides identification and characterization of genes underlying developmental and functional stages of nodulation and biological nitrogen fixation but also lays the foundation for further revelation of nod inducing gene family. Besides, identification and structural analysis of these genes in Arachis hypogaea may provide a theoretical basis for the study of evolutionary relationships in future analysis.
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Affiliation(s)
- Kiran Khurshid
- Department of Plant Biotechnology, Atta-ur-Rahman School of Applied Biosciences (ASAB), National University of Sciences and Technology (NUST), Islamabad, Pakistan
| | - Anum Akram
- Department of Plant Biotechnology, Atta-ur-Rahman School of Applied Biosciences (ASAB), National University of Sciences and Technology (NUST), Islamabad, Pakistan
| | - Ahmad Ali
- Department of Plant Biotechnology, Atta-ur-Rahman School of Applied Biosciences (ASAB), National University of Sciences and Technology (NUST), Islamabad, Pakistan
| | - Faiza Munir
- Department of Plant Biotechnology, Atta-ur-Rahman School of Applied Biosciences (ASAB), National University of Sciences and Technology (NUST), Islamabad, Pakistan
| | - Alvina Gul
- Department of Plant Biotechnology, Atta-ur-Rahman School of Applied Biosciences (ASAB), National University of Sciences and Technology (NUST), Islamabad, Pakistan
| | - Ghulam Haider
- Department of Plant Biotechnology, Atta-ur-Rahman School of Applied Biosciences (ASAB), National University of Sciences and Technology (NUST), Islamabad, Pakistan
| | - Zuhra Qayyum
- Department of Plant Biotechnology, Atta-ur-Rahman School of Applied Biosciences (ASAB), National University of Sciences and Technology (NUST), Islamabad, Pakistan
| | - Rabia Amir
- Department of Plant Biotechnology, Atta-ur-Rahman School of Applied Biosciences (ASAB), National University of Sciences and Technology (NUST), Islamabad, Pakistan
- * E-mail: ,
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Leal-Bertioli SCM, Nascimento EFMB, Chavarro MCF, Custódio AR, Hopkins MS, Moretzsohn MC, Bertioli DJ, Araújo ACG. Spontaneous generation of diversity in Arachis neopolyploids (Arachis ipaënsis × Arachis duranensis)4x replays the early stages of peanut evolution. G3-GENES GENOMES GENETICS 2021; 11:6353644. [PMID: 34510200 PMCID: PMC8527490 DOI: 10.1093/g3journal/jkab289] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/04/2021] [Accepted: 08/01/2021] [Indexed: 02/05/2023]
Abstract
Polyploidy is considered a driving force in plant evolution and domestication. Although in the genus Arachis, several diploid species were traditionally cultivated for their seeds, only the allotetraploid peanut Arachis hypogaea became the successful, widely spread legume crop. This suggests that polyploidy has given selective advantage for domestication of peanut. Here, we study induced allotetraploid (neopolyploid) lineages obtained from crosses between the peanut's progenitor species, Arachis ipaënsis and Arachis duranensis, at earlier and later generations. We observed plant morphology, seed dimensions, and genome structure using cytogenetics (FISH and GISH) and SNP genotyping. The neopolyploid lineages show more variable fertility and seed morphology than their progenitors and cultivated peanut. They also showed sexual and somatic genome instability, evidenced by changes of number of detectable 45S rDNA sites, and extensive homoeologous recombination indicated by mosaic patterns of chromosomes and changes in dosage of SNP alleles derived from the diploid species. Genome instability was not randomly distributed across the genome: the more syntenic chromosomes, the higher homoeologous recombination. Instability levels are higher than observed on peanut lines, therefore it is likely that more unstable lines tend to perish. We conclude that early stages of the origin and domestication of the allotetraploid peanut involved two genetic bottlenecks: the first, common to most allotetraploids, is composed of the rare hybridization and polyploidization events, followed by sexual reproductive isolation from its wild diploid relatives. Here, we suggest a second bottleneck: the survival of the only very few lineages that had stronger mechanisms for limiting genomic instability.
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Affiliation(s)
- Soraya C M Leal-Bertioli
- Institute of Plant Breeding, Genetics and Genomics, Athens, GA 30602-6810, USA.,Department of Plant Pathology, University of Georgia, Athens, GA 30602, USA
| | - Eliza F M B Nascimento
- Embrapa Genetic Resources and Biotechnology, Brasília, 70770-917, Brazill.,Institute of Biological Sciences, University of Brasilia, Brasília, 70910-000, Brazil
| | | | - Adriana R Custódio
- Embrapa Genetic Resources and Biotechnology, Brasília, 70770-917, Brazill
| | - Mark S Hopkins
- Institute of Plant Breeding, Genetics and Genomics, Athens, GA 30602-6810, USA
| | | | - David J Bertioli
- Institute of Plant Breeding, Genetics and Genomics, Athens, GA 30602-6810, USA.,Department of Crop and Soil Science, University of Georgia, Athens, GA 30602-6810, USA
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Fu L, Wang Q, Li L, Lang T, Guo J, Wang S, Sun Z, Han S, Huang B, Dong W, Zhang X, Du P. Physical mapping of repetitive oligonucleotides facilitates the establishment of a genome map-based karyotype to identify chromosomal variations in peanut. BMC PLANT BIOLOGY 2021; 21:107. [PMID: 33610178 PMCID: PMC7896385 DOI: 10.1186/s12870-021-02875-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/23/2020] [Accepted: 02/04/2021] [Indexed: 06/12/2023]
Abstract
BACKGROUND Chromosomal variants play important roles in crop breeding and genetic research. The development of single-stranded oligonucleotide (oligo) probes simplifies the process of fluorescence in situ hybridization (FISH) and facilitates chromosomal identification in many species. Genome sequencing provides rich resources for the development of oligo probes. However, little progress has been made in peanut due to the lack of efficient chromosomal markers. Until now, the identification of chromosomal variants in peanut has remained a challenge. RESULTS A total of 114 new oligo probes were developed based on the genome-wide tandem repeats (TRs) identified from the reference sequences of the peanut variety Tifrunner (AABB, 2n = 4x = 40) and the diploid species Arachis ipaensis (BB, 2n = 2x = 20). These oligo probes were classified into 28 types based on their positions and overlapping signals in chromosomes. For each type, a representative oligo was selected and modified with green fluorescein 6-carboxyfluorescein (FAM) or red fluorescein 6-carboxytetramethylrhodamine (TAMRA). Two cocktails, Multiplex #3 and Multiplex #4, were developed by pooling the fluorophore conjugated probes. Multiplex #3 included FAM-modified oligo TIF-439, oligo TIF-185-1, oligo TIF-134-3 and oligo TIF-165. Multiplex #4 included TAMRA-modified oligo Ipa-1162, oligo Ipa-1137, oligo DP-1 and oligo DP-5. Each cocktail enabled the establishment of a genome map-based karyotype after sequential FISH/genomic in situ hybridization (GISH) and in silico mapping. Furthermore, we identified 14 chromosomal variants of the peanut induced by radiation exposure. A total of 28 representative probes were further chromosomally mapped onto the new karyotype. Among the probes, eight were mapped in the secondary constrictions, intercalary and terminal regions; four were B genome-specific; one was chromosome-specific; and the remaining 15 were extensively mapped in the pericentric regions of the chromosomes. CONCLUSIONS The development of new oligo probes provides an effective set of tools which can be used to distinguish the various chromosomes of the peanut. Physical mapping by FISH reveals the genomic organization of repetitive oligos in peanut chromosomes. A genome map-based karyotype was established and used for the identification of chromosome variations in peanut following comparisons with their reference sequence positions.
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Affiliation(s)
- Liuyang Fu
- School of Life Sciences, Zhengzhou University, Zhengzhou, 450001, Henan, China
- Henan Academy of Crop Molecular Breeding, Henan Academy of Agricultural Sciences/Key Laboratory of Oil Crops in Huang-Huai-Hai Plains, Ministry of Agriculture/Henan Provincial Key Laboratory for Oil Crops Improvement, Zhengzhou, 450002, Henan, China
| | - Qian Wang
- Henan Academy of Crop Molecular Breeding, Henan Academy of Agricultural Sciences/Key Laboratory of Oil Crops in Huang-Huai-Hai Plains, Ministry of Agriculture/Henan Provincial Key Laboratory for Oil Crops Improvement, Zhengzhou, 450002, Henan, China
| | - Lina Li
- Henan Academy of Crop Molecular Breeding, Henan Academy of Agricultural Sciences/Key Laboratory of Oil Crops in Huang-Huai-Hai Plains, Ministry of Agriculture/Henan Provincial Key Laboratory for Oil Crops Improvement, Zhengzhou, 450002, Henan, China
| | - Tao Lang
- Institute of Biotechnology and Nuclear Technology, Sichuan Academy of Agricultural Sciences, Chengdu, 610061, Sichuan, China
| | - Junjia Guo
- School of Life Sciences, Zhengzhou University, Zhengzhou, 450001, Henan, China
- Henan Academy of Crop Molecular Breeding, Henan Academy of Agricultural Sciences/Key Laboratory of Oil Crops in Huang-Huai-Hai Plains, Ministry of Agriculture/Henan Provincial Key Laboratory for Oil Crops Improvement, Zhengzhou, 450002, Henan, China
| | - Siyu Wang
- School of Life Sciences, Zhengzhou University, Zhengzhou, 450001, Henan, China
- Henan Academy of Crop Molecular Breeding, Henan Academy of Agricultural Sciences/Key Laboratory of Oil Crops in Huang-Huai-Hai Plains, Ministry of Agriculture/Henan Provincial Key Laboratory for Oil Crops Improvement, Zhengzhou, 450002, Henan, China
| | - Ziqi Sun
- Henan Academy of Crop Molecular Breeding, Henan Academy of Agricultural Sciences/Key Laboratory of Oil Crops in Huang-Huai-Hai Plains, Ministry of Agriculture/Henan Provincial Key Laboratory for Oil Crops Improvement, Zhengzhou, 450002, Henan, China
| | - Suoyi Han
- Henan Academy of Crop Molecular Breeding, Henan Academy of Agricultural Sciences/Key Laboratory of Oil Crops in Huang-Huai-Hai Plains, Ministry of Agriculture/Henan Provincial Key Laboratory for Oil Crops Improvement, Zhengzhou, 450002, Henan, China
| | - Bingyan Huang
- Henan Academy of Crop Molecular Breeding, Henan Academy of Agricultural Sciences/Key Laboratory of Oil Crops in Huang-Huai-Hai Plains, Ministry of Agriculture/Henan Provincial Key Laboratory for Oil Crops Improvement, Zhengzhou, 450002, Henan, China
| | - Wenzhao Dong
- Henan Academy of Crop Molecular Breeding, Henan Academy of Agricultural Sciences/Key Laboratory of Oil Crops in Huang-Huai-Hai Plains, Ministry of Agriculture/Henan Provincial Key Laboratory for Oil Crops Improvement, Zhengzhou, 450002, Henan, China
| | - Xinyou Zhang
- Henan Academy of Crop Molecular Breeding, Henan Academy of Agricultural Sciences/Key Laboratory of Oil Crops in Huang-Huai-Hai Plains, Ministry of Agriculture/Henan Provincial Key Laboratory for Oil Crops Improvement, Zhengzhou, 450002, Henan, China.
| | - Pei Du
- Henan Academy of Crop Molecular Breeding, Henan Academy of Agricultural Sciences/Key Laboratory of Oil Crops in Huang-Huai-Hai Plains, Ministry of Agriculture/Henan Provincial Key Laboratory for Oil Crops Improvement, Zhengzhou, 450002, Henan, China.
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Nascimento EFDMBD, Leal-Bertioli SCDM, Bertioli DJ, Chavarro C, Freitas FO, Moretzsohn MDC, Guimarães PM, Valls JFM, Araujo ACGD. Brazilian Kayabi Indian accessions of peanut, Arachis hypogaea (Fabales, Fabaceae): origin, diversity and evolution. Genet Mol Biol 2020; 43:e20190418. [PMID: 33174976 PMCID: PMC7644258 DOI: 10.1590/1678-4685-gmb-2019-0418] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2020] [Accepted: 08/26/2020] [Indexed: 11/22/2022] Open
Abstract
Peanut is a crop of the Kayabi tribe, inhabiting the Xingu Indigenous Park, Brazil. Morphological analysis of Xingu accessions showed variation exceeding that described for cultivated peanuts. This raised questions as to the origin of the Xingu accessions: are they derived from different species, or is their diversity a result of different evolutionary and selection processes? To answer these questions, cytogenetic and genotyping analyses were conducted. The karyotypes of Xingu accessions analyzed are very similar to each other, to an A. hypogaea subsp. fastigiata accession and to the wild allotetraploid A. monticola. The accessions share the number and general morphology of the chromosomes; DAPI+ bands; 5S and 45S rDNA loci distribution and a high genomic affinity with A. duranensis and A. ipaënsis genomic probes. However, the number of CMA3+ bands differs from those determined for A. hypogaea and A. monticola, which are also different from each other. SNP genotyping grouped all Arachis allotetraploids into four taxonomic groups: Xingu accessions were closer to A. monticola and A. hypogaea subsp. hypogaea. Our data suggests that the morphological diversity within these accessions is not associated with a different origin and can be attributed to morphological plasticity and different selection by the Indian tribes.
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Affiliation(s)
| | | | - David John Bertioli
- University of Georgia, Center for Applied Genetic Technologies, Athens, GA, USA
| | - Carolina Chavarro
- University of Georgia, Center for Applied Genetic Technologies, Athens, GA, USA
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Silvestri MC, Ortiz AM, Robledo GA, Lavia GI. Chromosome diversity in species of the genus Arachis, revealed by FISH and CMA/DAPI banding, and inferences about their karyotype differentiation. AN ACAD BRAS CIENC 2020; 92:e20191364. [PMID: 32901677 DOI: 10.1590/0001-3765202020191364] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2018] [Accepted: 03/11/2019] [Indexed: 11/22/2022] Open
Abstract
The species of the genus Arachis (Leguminosae) are ordered into nine sections. The assignment of genome types in this genus has been based on cross-compatibility analysis and molecular cytogenetic studies. The latter has also allowed karyotypically establishing well-defined genomes and reassigning the genome of several species. However, most of these studies have been focused mainly on the sections Arachis and Rhizomatosae. To increase the knowledge about the chromosome diversity of the whole genus, here we performed a detailed karyotype characterization of representative species of most of the sections and genomes of Arachis. This characterization included chromosome morphology, CMA/DAPI chromosome banding, and chromosome marker localization (rDNAloci and one satDNA sequence) by fluorescent in situ hybridization (FISH). Based on the data obtained and other previously published data, we established the karyotype similarities by cluster analysis and defined eleven karyotype groups. The grouping was partly coincident with the traditional genome assignment, except for some groups and some individual species. Karyotype similarities among some genomes were also found. The main characteristics of each karyotype group of Arachis were summarized. Together, our results provide information that may be beneficial for future cytogenetic and evolutionary studies, and also contribute to the identification of interspecific hybrids.
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Affiliation(s)
- MarÍa C Silvestri
- Instituto de Botánica del Nordeste (CONICET-UNNE, Fac. Cs. Agrarias), Sargento Cabral 2131, C.C. 209, 3400 Corrientes, Argentina
| | - Alejandra M Ortiz
- Instituto de Botánica del Nordeste (CONICET-UNNE, Fac. Cs. Agrarias), Sargento Cabral 2131, C.C. 209, 3400 Corrientes, Argentina
| | - GermÁn A Robledo
- Instituto de Botánica del Nordeste (CONICET-UNNE, Fac. Cs. Agrarias), Sargento Cabral 2131, C.C. 209, 3400 Corrientes, Argentina.,Facultad de Ciencias Exactas y Naturales y Agrimensura, UNNE, Av. Libertad 5460, 3400 Corrientes, Argentina
| | - Graciela I Lavia
- Instituto de Botánica del Nordeste (CONICET-UNNE, Fac. Cs. Agrarias), Sargento Cabral 2131, C.C. 209, 3400 Corrientes, Argentina.,Facultad de Ciencias Exactas y Naturales y Agrimensura, UNNE, Av. Libertad 5460, 3400 Corrientes, Argentina
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Li L, Hu B, Li X, Li L. Characterization of mTERF family in allotetraploid peanut and their expression levels in response to dehydration stress. BIOTECHNOL BIOTEC EQ 2020. [DOI: 10.1080/13102818.2020.1825121] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022] Open
Affiliation(s)
- Limei Li
- Guangdong Provincial Key Laboratory of Biotechnology for Plant Development, School of Life Science, South China Normal University, Guangzhou, Guangdong, PR China
| | - Bo Hu
- Guangdong Provincial Key Laboratory of Biotechnology for Plant Development, School of Life Science, South China Normal University, Guangzhou, Guangdong, PR China
| | - Xiaoyun Li
- Guangdong Provincial Key Laboratory of Biotechnology for Plant Development, School of Life Science, South China Normal University, Guangzhou, Guangdong, PR China
| | - Ling Li
- Guangdong Provincial Key Laboratory of Biotechnology for Plant Development, School of Life Science, South China Normal University, Guangzhou, Guangdong, PR China
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Samoluk SS, Chalup LMI, Chavarro C, Robledo G, Bertioli DJ, Jackson SA, Seijo G. Heterochromatin evolution in Arachis investigated through genome-wide analysis of repetitive DNA. PLANTA 2019; 249:1405-1415. [PMID: 30680457 DOI: 10.1007/s00425-019-03096-4] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/30/2018] [Accepted: 01/18/2019] [Indexed: 05/21/2023]
Abstract
The most conspicuous difference among chromosomes and genomes in Arachis species, the patterns of heterochromatin, was mainly modeled by differential amplification of different members of one superfamily of satellite DNAs. Divergence in repetitive DNA is a primary driving force for genome and chromosome evolution. Section Arachis is karyotypically diverse and has six different genomes. Arachis glandulifera (D genome) has the most asymmetric karyotype and the highest reproductive isolation compared to the well-known A and B genome species. These features make A. glandulifera an interesting model species for studying the main repetitive components that accompanied the genome and chromosome diversification in the section. Here, we performed a genome-wide analysis of repetitive sequences in A. glandulifera and investigated the chromosome distribution of the identified satellite DNA sequences (satDNAs). LTR retroelements, mainly the Ty3-gypsy families "Fidel/Feral" and "Pipoka/Pipa", were the most represented. Comparative analyses with the A and B genomes showed that many of the previously described transposable elements (TEs) were differently represented in the D genome, and that this variation accompanied changes in DNA content. In addition, four major satDNAs were characterized. Agla_CL8sat was the major component of pericentromeric heterochromatin, while Agla_CL39sat, Agla_CL69sat, and Agla_CL122sat were found in heterochromatic and/or euchromatic regions. Even though Agla_CL8sat belong to a different family than that of the major satDNA (ATR-2) found in the heterochromatin of the A, K, and F genomes, both satDNAs are members of the same superfamily. This finding suggests that closely related satDNAs of an ancestral library were differentially amplified leading to the major changes in the heterochromatin patterns that accompanied the karyotype and genome differentiation in Arachis.
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Affiliation(s)
- Sergio S Samoluk
- Facultad de Ciencias Agrarias, Instituto de Botánica del Nordeste (UNNE-CONICET), Corrientes, Argentina.
| | - Laura M I Chalup
- Facultad de Ciencias Agrarias, Instituto de Botánica del Nordeste (UNNE-CONICET), Corrientes, Argentina
| | - Carolina Chavarro
- Center for Applied Genetic Technologies, University of Georgia, Athens, GA, USA
| | - Germán Robledo
- Facultad de Ciencias Agrarias, Instituto de Botánica del Nordeste (UNNE-CONICET), Corrientes, Argentina
- Facultad de Ciencias Exactas y Naturales y Agrimensura, Universidad Nacional del Nordeste, Corrientes, Argentina
| | - David J Bertioli
- Center for Applied Genetic Technologies, University of Georgia, Athens, GA, USA
| | - Scott A Jackson
- Center for Applied Genetic Technologies, University of Georgia, Athens, GA, USA
| | - Guillermo Seijo
- Facultad de Ciencias Agrarias, Instituto de Botánica del Nordeste (UNNE-CONICET), Corrientes, Argentina
- Facultad de Ciencias Exactas y Naturales y Agrimensura, Universidad Nacional del Nordeste, Corrientes, Argentina
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Chu Y, Chee P, Culbreath A, Isleib TG, Holbrook CC, Ozias-Akins P. Major QTLs for Resistance to Early and Late Leaf Spot Diseases Are Identified on Chromosomes 3 and 5 in Peanut ( Arachis hypogaea). FRONTIERS IN PLANT SCIENCE 2019; 10:883. [PMID: 31333711 PMCID: PMC6625158 DOI: 10.3389/fpls.2019.00883] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/22/2018] [Accepted: 06/20/2019] [Indexed: 05/21/2023]
Abstract
Early and late leaf spots (LLSs) are the major foliar diseases of peanut responsible for severely decreased yield in the absence of intensive fungicide spray programs. Pyramiding host resistance to leaf spots in elite cultivars is a sustainable solution to mitigate the diseases. In order to determine the genetic control of leaf spot disease resistance in peanut, a recombinant inbred line population (Florida-07 × GP-NC WS16) segregating for resistance to both diseases was used to construct a SNP-based linkage map consisting of 855 loci. QTL mapping revealed three resistance QTLs for LLS qLLSA05 (phenotypic variation explained, PVE = 7-10%), qLLSB03 (PVE = 5-7%), and qLLSB05 (PVE = 15-41%) that were consistently expressed over multi-year analysis. Two QTL, qLLSA05 and qLLSB05, confirmed our previously published QTL-seq results. For early leaf spot, three resistance QTLs were identified in multiple years, two on chromosome A03 (PVE = 8-12%) and one on chromosome B03 (PVE = 13-20%), with the locus qELSA03_1.1 coinciding with the previously published genomic region for LLS resistance in GPBD4. Comparative analysis of the genomic regions spanning the QTLs suggests that resistance to early and LLSs are largely genetically independent. In addition, QTL analysis on yield showed that the presence of resistance allele in qLLSB03 and qLLSB05 loci might result in protection from yield loss caused by LLS disease damage. Finally, post hoc analysis of the RIL subpopulation that was not utilized in the QTL mapping revealed that the flanking markers for these QTLs can successfully select for resistant and susceptible lines, confirming the effectiveness of pyramiding these resistance loci to improve host-plant resistance in peanut breeding programs using marker-assisted selection.
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Affiliation(s)
- Ye Chu
- Department of Horticulture, The University of Georgia Tifton Campus, Tifton, GA, United States
| | - Peng Chee
- Department of Crop and Soil Sciences, The University of Georgia Tifton Campus, Tifton, GA, United States
- Institute of Plant Breeding, Genetics and Genomics, The University of Georgia Tifton Campus, Tifton, GA, United States
| | - Albert Culbreath
- Department of Plant Pathology, University of Georgia, Tifton, GA, United States
| | - Thomas G. Isleib
- Department of Crop and Soil Sciences, North Carolina State University, Raleigh, NC, United States
| | - C. Corley Holbrook
- Institute of Plant Breeding, Genetics and Genomics, The University of Georgia Tifton Campus, Tifton, GA, United States
- United States Department of Agriculture (USDA), Agricultural Research Service, Crop Genetics and Breeding Research Unit, Tifton, GA, United States
| | - Peggy Ozias-Akins
- Department of Horticulture, The University of Georgia Tifton Campus, Tifton, GA, United States
- Institute of Plant Breeding, Genetics and Genomics, The University of Georgia Tifton Campus, Tifton, GA, United States
- *Correspondence: Peggy Ozias-Akins,
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