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Cui Y, Xiao X, Wang M, Zhu M, Yuyama N, Zheng J, Xiong C, Liu J, Wang S, Yang Y, Chen J, Cai H. The construction of a maize-teosinte introgression population and quantitative trait loci analysis of their 21 agronomic traits. PLANT SCIENCE : AN INTERNATIONAL JOURNAL OF EXPERIMENTAL PLANT BIOLOGY 2024; 348:112226. [PMID: 39153574 DOI: 10.1016/j.plantsci.2024.112226] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/10/2024] [Revised: 08/03/2024] [Accepted: 08/12/2024] [Indexed: 08/19/2024]
Abstract
Teosinte is a progenitor species of maize (Zea mays ssp. mays) that retains a significant reservoir of genetic resources unaltered via the domestication process. To harness and explore the genetic reservoirs inherent in teosinte, we used the cultivated publicly inbred line H95 and wild species PI566673 (Zea mays ssp. mexicana) to develop a set of introgression lines (ILs), including 366 BC2F5 lines. Using these lines, 12481 high-quality polymorphic homozygous single nucleotide polymorphisms were converted into 2358 bin markers based on Genotyping by Target Sequencing technology. The homozygous introgression ratio in the ILs was approximately 12.1 % and the heterozygous introgression ratio was approximately 5.7 %. Based on the population phenotypic data across 21 important agronomic traits collected in Sanya and Beijing, 185 and 156 quantitative trait loci (QTLs) were detected in Sanya and Beijing, respectively, with 64 stable QTLs detected in both locations. We detected 12 QTL clusters spanning 10 chromosomes consisting of diverse QTLs related to yield traits such as grain size and weight. In addition, we identified useful materials in the ILs for further gene cloning of related variations. For example, some heterogeneous inbred families with superior genetic purity, shorter target heterozygotes, and some ILs exhibit clear morphological variation associated with plant growth, development, and domestication, manifesting traits such as white stalks, sharp seeds, and cob shattering. In conclusion, our results provide a robust foundation for delving into the genetic reservoirs of teosinte, presenting a wealth of genetic resources and offering insight into the genetic architecture underlying maize agronomic traits.
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Affiliation(s)
- Yiping Cui
- College of Agronomy and Biotechnology, China Agricultural University, Beijing 100193, China
| | - Xin Xiao
- College of Agronomy and Biotechnology, China Agricultural University, Beijing 100193, China
| | - Mumu Wang
- Crop Research Institute, Shandong Academy of Agricultural Sciences, Jinan 250100, China
| | - Mengjiao Zhu
- College of Agronomy and Biotechnology, China Agricultural University, Beijing 100193, China
| | - Nana Yuyama
- Forage Crop Research Institute, Japan Grassland Agricultural and Forage Seed Association, 388-5 Higashiakada, Nasushiobara, Tochigi 329-2742, Japan
| | - Jingru Zheng
- College of Grassland Science and Technology, China Agricultural University, Beijing 100193, China
| | - Candong Xiong
- College of Grassland Science and Technology, China Agricultural University, Beijing 100193, China
| | - Jiangjiang Liu
- College of Agronomy and Biotechnology, China Agricultural University, Beijing 100193, China
| | - Sumeng Wang
- College of Agronomy and Biotechnology, China Agricultural University, Beijing 100193, China
| | - Yuru Yang
- College of Grassland Science and Technology, China Agricultural University, Beijing 100193, China
| | - Jun Chen
- College of Agronomy and Biotechnology, China Agricultural University, Beijing 100193, China.
| | - Hongwei Cai
- College of Agronomy and Biotechnology, China Agricultural University, Beijing 100193, China; Forage Crop Research Institute, Japan Grassland Agricultural and Forage Seed Association, 388-5 Higashiakada, Nasushiobara, Tochigi 329-2742, Japan.
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2
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Cannon EK, Portwood JL, Hayford RK, Haley OC, Gardiner JM, Andorf CM, Woodhouse MR. Enhanced pan-genomic resources at the maize genetics and genomics database. Genetics 2024; 227:iyae036. [PMID: 38577974 DOI: 10.1093/genetics/iyae036] [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: 11/13/2023] [Accepted: 01/13/2024] [Indexed: 04/06/2024] Open
Abstract
Pan-genomes, encompassing the entirety of genetic sequences found in a collection of genomes within a clade, are more useful than single reference genomes for studying species diversity. This is especially true for a species like Zea mays, which has a particularly diverse and complex genome. Presenting pan-genome data, analyses, and visualization is challenging, especially for a diverse species, but more so when pan-genomic data is linked to extensive gene model and gene data, including classical gene information, markers, insertions, expression and proteomic data, and protein structures as is the case at MaizeGDB. Here, we describe MaizeGDB's expansion to include the genic subset of the Zea pan-genome in a pan-gene data center featuring the maize genomes hosted at MaizeGDB, and the outgroup teosinte Zea genomes from the Pan-Andropoganeae project. The new data center offers a variety of browsing and visualization tools, including sequence alignment visualization, gene trees and other tools, to explore pan-genes in Zea that were calculated by the pipeline Pandagma. Combined, these data will help maize researchers study the complexity and diversity of Zea, and to use the comparative functions to validate pan-gene relationships for a selected gene model.
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Affiliation(s)
- Ethalinda K Cannon
- USDA-ARS, Corn Insects and Crop Genetics Research Unit, Ames, IA 50011, USA
| | - John L Portwood
- USDA-ARS, Corn Insects and Crop Genetics Research Unit, Ames, IA 50011, USA
| | - Rita K Hayford
- USDA-ARS, Corn Insects and Crop Genetics Research Unit, Ames, IA 50011, USA
| | - Olivia C Haley
- USDA-ARS, Corn Insects and Crop Genetics Research Unit, Ames, IA 50011, USA
| | - Jack M Gardiner
- Division of Animal Sciences, University of Missouri, Columbia, MO 65211, USA
| | - Carson M Andorf
- USDA-ARS, Corn Insects and Crop Genetics Research Unit, Ames, IA 50011, USA
- Department of Computer Science, Iowa State University, Ames, IA 50011, USA
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3
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Gepts P. Biocultural diversity and crop improvement. Emerg Top Life Sci 2023; 7:151-196. [PMID: 38084755 PMCID: PMC10754339 DOI: 10.1042/etls20230067] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2023] [Revised: 11/26/2023] [Accepted: 11/27/2023] [Indexed: 12/30/2023]
Abstract
Biocultural diversity is the ever-evolving and irreplaceable sum total of all living organisms inhabiting the Earth. It plays a significant role in sustainable productivity and ecosystem services that benefit humanity and is closely allied with human cultural diversity. Despite its essentiality, biodiversity is seriously threatened by the insatiable and inequitable human exploitation of the Earth's resources. One of the benefits of biodiversity is its utilization in crop improvement, including cropping improvement (agronomic cultivation practices) and genetic improvement (plant breeding). Crop improvement has tended to decrease agricultural biodiversity since the origins of agriculture, but awareness of this situation can reverse this negative trend. Cropping improvement can strive to use more diverse cultivars and a broader complement of crops on farms and in landscapes. It can also focus on underutilized crops, including legumes. Genetic improvement can access a broader range of biodiversity sources and, with the assistance of modern breeding tools like genomics, can facilitate the introduction of additional characteristics that improve yield, mitigate environmental stresses, and restore, at least partially, lost crop biodiversity. The current legal framework covering biodiversity includes national intellectual property and international treaty instruments, which have tended to limit access and innovation to biodiversity. A global system of access and benefit sharing, encompassing digital sequence information, would benefit humanity but remains an elusive goal. The Kunming-Montréal Global Biodiversity Framework sets forth an ambitious set of targets and goals to be accomplished by 2030 and 2050, respectively, to protect and restore biocultural diversity, including agrobiodiversity.
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Affiliation(s)
- Paul Gepts
- Department of Plant Sciences, Section of Crop and Ecosystem Sciences, University of California, Davis, CA 95616-8780, U.S.A
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4
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Cagirici HB, Andorf CM, Sen TZ. Co-expression pan-network reveals genes involved in complex traits within maize pan-genome. BMC PLANT BIOLOGY 2022; 22:595. [PMID: 36529716 PMCID: PMC9762053 DOI: 10.1186/s12870-022-03985-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/15/2022] [Accepted: 12/07/2022] [Indexed: 06/17/2023]
Abstract
BACKGROUND With the advances in the high throughput next generation sequencing technologies, genome-wide association studies (GWAS) have identified a large set of variants associated with complex phenotypic traits at a very fine scale. Despite the progress in GWAS, identification of genotype-phenotype relationship remains challenging in maize due to its nature with dozens of variants controlling the same trait. As the causal variations results in the change in expression, gene expression analyses carry a pivotal role in unraveling the transcriptional regulatory mechanisms behind the phenotypes. RESULTS To address these challenges, we incorporated the gene expression and GWAS-driven traits to extend the knowledge of genotype-phenotype relationships and transcriptional regulatory mechanisms behind the phenotypes. We constructed a large collection of gene co-expression networks and identified more than 2 million co-expressing gene pairs in the GWAS-driven pan-network which contains all the gene-pairs in individual genomes of the nested association mapping (NAM) population. We defined four sub-categories for the pan-network: (1) core-network contains the highest represented ~ 1% of the gene-pairs, (2) near-core network contains the next highest represented 1-5% of the gene-pairs, (3) private-network contains ~ 50% of the gene pairs that are unique to individual genomes, and (4) the dispensable-network contains the remaining 50-95% of the gene-pairs in the maize pan-genome. Strikingly, the private-network contained almost all the genes in the pan-network but lacked half of the interactions. We performed gene ontology (GO) enrichment analysis for the pan-, core-, and private- networks and compared the contributions of variants overlapping with genes and promoters to the GWAS-driven pan-network. CONCLUSIONS Gene co-expression networks revealed meaningful information about groups of co-regulated genes that play a central role in regulatory processes. Pan-network approach enabled us to visualize the global view of the gene regulatory network for the studied system that could not be well inferred by the core-network alone.
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Affiliation(s)
- H Busra Cagirici
- US Department of Agriculture - Agricultural Research Service, Crop Improvement Genetics Research Unit, Western Regional Research Center, 800 Buchanan St, Albany, CA, 94710, USA
| | - Carson M Andorf
- US Department of Agriculture - Agricultural Research Service, Corn Insects and Crop Genetics Research Unit, Iowa State University, Ames, IA, 50011, USA.
- Department of Computer Science, Iowa State University, Ames, IA, 50011, USA.
| | - Taner Z Sen
- US Department of Agriculture - Agricultural Research Service, Crop Improvement Genetics Research Unit, Western Regional Research Center, 800 Buchanan St, Albany, CA, 94710, USA.
- Department of Bioengineering, University of California, Berkeley, CA, 94720, USA.
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5
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Sardos J, Breton C, Perrier X, Van den Houwe I, Carpentier S, Paofa J, Rouard M, Roux N. Hybridization, missing wild ancestors and the domestication of cultivated diploid bananas. FRONTIERS IN PLANT SCIENCE 2022; 13:969220. [PMID: 36275535 PMCID: PMC9586208 DOI: 10.3389/fpls.2022.969220] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/14/2022] [Accepted: 09/05/2022] [Indexed: 06/08/2023]
Abstract
Hybridization and introgressions are important evolutionary forces in plants. They contribute to the domestication of many species, including understudied clonal crops. Here, we examine their role in the domestication of a clonal crop of outmost importance, banana (Musa ssp.). We used genome-wide SNPs generated for 154 diploid banana cultivars and 68 samples of the wild M. acuminata to estimate and geo-localize the contribution of the different subspecies of M. acuminata to cultivated banana. We further investigated the wild to domesticate transition in New Guinea, an important domestication center. We found high levels of admixture in many cultivars and confirmed the existence of unknown wild ancestors with unequal contributions to cultivated diploid. In New Guinea, cultivated accessions exhibited higher diversity than their direct wild ancestor, the latter recovering from a bottleneck. Introgressions, balancing selection and positive selection were identified as important mechanisms for banana domestication. Our results shed new lights on the radiation of M. acuminata subspecies and on how they shaped banana domestication. They point candidate regions of origin for two unknown ancestors and suggest another contributor in New Guinea. This work feed research on the evolution of clonal crops and has direct implications for conservation, collection, and breeding.
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Affiliation(s)
- Julie Sardos
- Bioversity International, Parc Scientifique Agropolis II, Montpellier, France
| | - Catherine Breton
- Bioversity International, Parc Scientifique Agropolis II, Montpellier, France
| | - Xavier Perrier
- CIRAD, UMR AGAP Institut, Montpellier, France
- UMR AGAP Institut, Univ Montpellier, CIRAD, INRAE, Institut Agro, Montpellier, France
| | | | | | - Janet Paofa
- Papua New Guinea (PNG) National Agricultural Research Institute, Southern Regional Centre, Laloki, Port Moresby, Papua New Guinea
| | - Mathieu Rouard
- Bioversity International, Parc Scientifique Agropolis II, Montpellier, France
| | - Nicolas Roux
- Bioversity International, Parc Scientifique Agropolis II, Montpellier, France
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Blanco Pastor JL. Alternative modes of introgression-mediated selection shaped crop adaptation to novel climates. Genome Biol Evol 2022; 14:6647590. [PMID: 35859297 PMCID: PMC9348624 DOI: 10.1093/gbe/evac107] [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] [Accepted: 07/11/2022] [Indexed: 11/16/2022] Open
Abstract
Recent plant genomic studies provide fine-grained details on the evolutionary consequences of adaptive introgression during crop domestication. Modern genomic approaches and analytical methods now make it possible to better separate the introgression signal from the demographic signal thus providing a more comprehensive and complex picture of the role of introgression in local adaptation. Adaptive introgression has been fundamental for crop expansion and has involved complex patterns of gene flow. In addition to providing new and more favorable alleles of large effect, introgression during the early stages of domestication also increased allelic diversity at adaptive loci. Previous studies have largely underestimated the effect of such increased diversity following introgression. Recent genomic studies in wheat, potato, maize, grapevine, and ryegrass show that introgression of multiple genes, of as yet unknown effect, increased the effectiveness of purifying selection, and promoted disruptive or fluctuating selection in early cultivars and landraces. Historical selection processes associated with introgression from crop wild relatives provide an instructive analog for adaptation to current climate change and offer new avenues for crop breeding research that are expected to be instrumental for strengthening food security in the coming years.
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An adaptive teosinte mexicana introgression modulates phosphatidylcholine levels and is associated with maize flowering time. Proc Natl Acad Sci U S A 2022; 119:e2100036119. [PMID: 35771940 PMCID: PMC9271162 DOI: 10.1073/pnas.2100036119] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
Native Americans domesticated maize (Zea mays ssp. mays) from lowland teosinte parviglumis (Zea mays ssp. parviglumis) in the warm Mexican southwest and brought it to the highlands of Mexico and South America where it was exposed to lower temperatures that imposed strong selection on flowering time. Phospholipids are important metabolites in plant responses to low-temperature and phosphorus availability and have been suggested to influence flowering time. Here, we combined linkage mapping with genome scans to identify High PhosphatidylCholine 1 (HPC1), a gene that encodes a phospholipase A1 enzyme, as a major driver of phospholipid variation in highland maize. Common garden experiments demonstrated strong genotype-by-environment interactions associated with variation at HPC1, with the highland HPC1 allele leading to higher fitness in highlands, possibly by hastening flowering. The highland maize HPC1 variant resulted in impaired function of the encoded protein due to a polymorphism in a highly conserved sequence. A meta-analysis across HPC1 orthologs indicated a strong association between the identity of the amino acid at this position and optimal growth in prokaryotes. Mutagenesis of HPC1 via genome editing validated its role in regulating phospholipid metabolism. Finally, we showed that the highland HPC1 allele entered cultivated maize by introgression from the wild highland teosinte Zea mays ssp. mexicana and has been maintained in maize breeding lines from the Northern United States, Canada, and Europe. Thus, HPC1 introgressed from teosinte mexicana underlies a large metabolic QTL that modulates phosphatidylcholine levels and has an adaptive effect at least in part via induction of early flowering time.
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Alonso‐Nieves AL, Salazar‐Vidal MN, Torres‐Rodríguez JV, Pérez‐Vázquez LM, Massange‐Sánchez JA, Gillmor CS, Sawers RJH. The pho1;2a'-m1.1 allele of Phosphate1 conditions misregulation of the phosphorus starvation response in maize ( Zea mays ssp. mays L.). PLANT DIRECT 2022; 6:e416. [PMID: 35844781 PMCID: PMC9277030 DOI: 10.1002/pld3.416] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/14/2022] [Revised: 06/12/2022] [Accepted: 06/13/2022] [Indexed: 06/15/2023]
Abstract
Plant PHO1 proteins play a central role in the translocation and sensing of inorganic phosphate. The maize (Zea mays ssp. mays) genome encodes two co-orthologs of the Arabidopsis PHO1 gene, designated ZmPho1;2a and ZmPho1;2b. Here, we report the characterization of the transposon footprint allele Zmpho1;2a'-m1.1, which we refer to hereafter as pho1;2a. The pho1;2a allele is a stable derivative formed by excision of an Activator transposable element from the ZmPho1;2a gene. The pho1;2a allele contains an 8-bp insertion at the point of transposon excision that disrupts the reading frame and is predicted to generate a premature translational stop. We show that the pho1;2a allele is linked to a dosage-dependent reduction in Pho1;2a transcript accumulation and a mild reduction in seedling growth. Characterization of shoot and root transcriptomes under full nutrient, low nitrogen, low phosphorus, and combined low nitrogen and low phosphorus conditions identified 1100 differentially expressed genes between wild-type plants and plants carrying the pho1;2a mutation. Of these 1100 genes, 966 were upregulated in plants carrying pho1;2a, indicating the wild-type PHO1;2a to predominantly impact negative gene regulation. Gene set enrichment analysis of the pho1;2a-misregulated genes revealed associations with phytohormone signaling and the phosphate starvation response. In roots, differential expression was broadly consistent across all nutrient conditions. In leaves, differential expression was largely specific to low phosphorus and combined low nitrogen and low phosphorus conditions. Of 276 genes upregulated in the leaves of pho1;2a mutants in the low phosphorus condition, 153 were themselves induced in wild-type plants with respect to the full nutrient condition. Our observations suggest that Pho1;2a functions in the fine-tuning of the transcriptional response to phosphate starvation through maintenance and/or sensing of plant phosphate status.
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Affiliation(s)
- Ana Laura Alonso‐Nieves
- Langebio, Unidad de Genómica AvanzadaCentro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional (CINVESTAV‐IPN)IrapuatoMexico
| | - M. Nancy Salazar‐Vidal
- Langebio, Unidad de Genómica AvanzadaCentro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional (CINVESTAV‐IPN)IrapuatoMexico
- Department of Evolution and EcologyUniversity of California, DavisDavisCaliforniaUSA
- Division of Plant SciencesUniversity of MissouriColumbiaMissouriUSA
| | - J. Vladimir Torres‐Rodríguez
- Langebio, Unidad de Genómica AvanzadaCentro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional (CINVESTAV‐IPN)IrapuatoMexico
- Center for Plant Science InnovationUniversity of Nebraska‐LincolnLincolnNebraskaUSA
| | - Leonardo M. Pérez‐Vázquez
- Langebio, Unidad de Genómica AvanzadaCentro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional (CINVESTAV‐IPN)IrapuatoMexico
| | - Julio A. Massange‐Sánchez
- Langebio, Unidad de Genómica AvanzadaCentro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional (CINVESTAV‐IPN)IrapuatoMexico
- Unidad de Biotecnología VegetalCentro de Investigación y Asistencia en Tecnología y Diseño del Estado de Jalisco A.C. (CIATEJ) Subsede ZapopanGuadalajaraMexico
| | - C. Stewart Gillmor
- Langebio, Unidad de Genómica AvanzadaCentro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional (CINVESTAV‐IPN)IrapuatoMexico
| | - Ruairidh J. H. Sawers
- Langebio, Unidad de Genómica AvanzadaCentro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional (CINVESTAV‐IPN)IrapuatoMexico
- Department of Plant ScienceThe Pennsylvania State UniversityState CollegePennsylvaniaUSA
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Filyushin MA, Khatefov EB, Kochieva EZ, Shchennikova AV. Comparative Analysis of Transcription Factor Genes liguleless1 and liguleless1-like in Teosinte and Modern Maize Accessions. RUSS J GENET+ 2022. [DOI: 10.1134/s102279542203005x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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10
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Perez-Limón S, Li M, Cintora-Martinez GC, Aguilar-Rangel MR, Salazar-Vidal MN, González-Segovia E, Blöcher-Juárez K, Guerrero-Zavala A, Barrales-Gamez B, Carcaño-Macias J, Costich DE, Nieto-Sotelo J, Martinez de la Vega O, Simpson J, Hufford MB, Ross-Ibarra J, Flint-Garcia S, Diaz-Garcia L, Rellán-Álvarez R, Sawers RJH. A B73×Palomero Toluqueño mapping population reveals local adaptation in Mexican highland maize. G3 (BETHESDA, MD.) 2022; 12:jkab447. [PMID: 35100386 PMCID: PMC8896015 DOI: 10.1093/g3journal/jkab447] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/14/2021] [Accepted: 12/16/2021] [Indexed: 01/31/2023]
Abstract
Generations of farmer selection in the central Mexican highlands have produced unique maize varieties adapted to the challenges of the local environment. In addition to possessing great agronomic and cultural value, Mexican highland maize represents a good system for the study of local adaptation and acquisition of adaptive phenotypes under cultivation. In this study, we characterize a recombinant inbred line population derived from the B73 reference line and the Mexican highland maize variety Palomero Toluqueño. B73 and Palomero Toluqueño showed classic rank-changing differences in performance between lowland and highland field sites, indicative of local adaptation. Quantitative trait mapping identified genomic regions linked to effects on yield components that were conditionally expressed depending on the environment. For the principal genomic regions associated with ear weight and total kernel number, the Palomero Toluqueño allele conferred an advantage specifically in the highland site, consistent with local adaptation. We identified Palomero Toluqueño alleles associated with expression of characteristic highland traits, including reduced tassel branching, increased sheath pigmentation and the presence of sheath macrohairs. The oligogenic architecture of these three morphological traits supports their role in adaptation, suggesting they have arisen from consistent directional selection acting at distinct points across the genome. We discuss these results in the context of the origin of phenotypic novelty during selection, commenting on the role of de novo mutation and the acquisition of adaptive variation by gene flow from endemic wild relatives.
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Affiliation(s)
- Sergio Perez-Limón
- Laboratorio Nacional de Genómica para la Biodiversidad/Unidad de Genómica Avanzada, Centro de Investigación y de Estudios Avanzados, Instituto Politécnico Nacional (CINVESTAV-IPN), Irapuato, Guanajuato 36821, México
- Department of Plant Science, The Pennsylvania State University, State College, PA 16802, USA
| | - Meng Li
- Department of Plant Science, The Pennsylvania State University, State College, PA 16802, USA
| | - G Carolina Cintora-Martinez
- Laboratorio Nacional de Genómica para la Biodiversidad/Unidad de Genómica Avanzada, Centro de Investigación y de Estudios Avanzados, Instituto Politécnico Nacional (CINVESTAV-IPN), Irapuato, Guanajuato 36821, México
| | - M Rocio Aguilar-Rangel
- Laboratorio Nacional de Genómica para la Biodiversidad/Unidad de Genómica Avanzada, Centro de Investigación y de Estudios Avanzados, Instituto Politécnico Nacional (CINVESTAV-IPN), Irapuato, Guanajuato 36821, México
| | - M Nancy Salazar-Vidal
- Laboratorio Nacional de Genómica para la Biodiversidad/Unidad de Genómica Avanzada, Centro de Investigación y de Estudios Avanzados, Instituto Politécnico Nacional (CINVESTAV-IPN), Irapuato, Guanajuato 36821, México
- Department of Evolution and Ecology, UC Davis, CA 95616 USA
| | - Eric González-Segovia
- Laboratorio Nacional de Genómica para la Biodiversidad/Unidad de Genómica Avanzada, Centro de Investigación y de Estudios Avanzados, Instituto Politécnico Nacional (CINVESTAV-IPN), Irapuato, Guanajuato 36821, México
- Department of Botany, University of British Columbia, Vancouver, BC V6T 1Z4, Canada
| | - Karla Blöcher-Juárez
- Laboratorio Nacional de Genómica para la Biodiversidad/Unidad de Genómica Avanzada, Centro de Investigación y de Estudios Avanzados, Instituto Politécnico Nacional (CINVESTAV-IPN), Irapuato, Guanajuato 36821, México
| | - Alejandro Guerrero-Zavala
- Laboratorio Nacional de Genómica para la Biodiversidad/Unidad de Genómica Avanzada, Centro de Investigación y de Estudios Avanzados, Instituto Politécnico Nacional (CINVESTAV-IPN), Irapuato, Guanajuato 36821, México
| | - Benjamin Barrales-Gamez
- Laboratorio Nacional de Genómica para la Biodiversidad/Unidad de Genómica Avanzada, Centro de Investigación y de Estudios Avanzados, Instituto Politécnico Nacional (CINVESTAV-IPN), Irapuato, Guanajuato 36821, México
| | - Jessica Carcaño-Macias
- Laboratorio Nacional de Genómica para la Biodiversidad/Unidad de Genómica Avanzada, Centro de Investigación y de Estudios Avanzados, Instituto Politécnico Nacional (CINVESTAV-IPN), Irapuato, Guanajuato 36821, México
| | - Denise E Costich
- International Center for Maize and Wheat Improvement (CIMMyT), De México 56237, México
| | - Jorge Nieto-Sotelo
- Jardín Botánico, Instituto de Biología, Universidad Nacional Autónoma de México, Ciudad de México 04510, México
| | - Octavio Martinez de la Vega
- Laboratorio Nacional de Genómica para la Biodiversidad/Unidad de Genómica Avanzada, Centro de Investigación y de Estudios Avanzados, Instituto Politécnico Nacional (CINVESTAV-IPN), Irapuato, Guanajuato 36821, México
| | - June Simpson
- Laboratorio Nacional de Genómica para la Biodiversidad/Unidad de Genómica Avanzada, Centro de Investigación y de Estudios Avanzados, Instituto Politécnico Nacional (CINVESTAV-IPN), Irapuato, Guanajuato 36821, México
| | - Matthew B Hufford
- Department of Ecology, Evolution, and Organismal Biology, Iowa State University, Ames, IA 50011, USA
| | - Jeffrey Ross-Ibarra
- Department of Evolution and Ecology, UC Davis, CA 95616 USA
- Center for Population Biology, and Genome Center, UC Davis, Davis, CA 95616, USA
| | - Sherry Flint-Garcia
- U.S. Department of Agriculture, Agricultural Research Service Plant Genetics Research Unit, Columbia, MO 65211, USA
| | - Luis Diaz-Garcia
- Campo Experimental Pabellón-INIFAP. Carretera Aguascalientes-Zacatecas, Aguascalientes, CP 20660, México
| | - Rubén Rellán-Álvarez
- Laboratorio Nacional de Genómica para la Biodiversidad/Unidad de Genómica Avanzada, Centro de Investigación y de Estudios Avanzados, Instituto Politécnico Nacional (CINVESTAV-IPN), Irapuato, Guanajuato 36821, México
- Department of Molecular and Structural Biochemistry, North Carolina State University, Raleigh, NC 27695, USA
| | - Ruairidh J H Sawers
- Laboratorio Nacional de Genómica para la Biodiversidad/Unidad de Genómica Avanzada, Centro de Investigación y de Estudios Avanzados, Instituto Politécnico Nacional (CINVESTAV-IPN), Irapuato, Guanajuato 36821, México
- Department of Plant Science, The Pennsylvania State University, State College, PA 16802, USA
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11
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Toulotte JM, Pantazopoulou CK, Sanclemente MA, Voesenek LACJ, Sasidharan R. Water stress resilient cereal crops: Lessons from wild relatives. JOURNAL OF INTEGRATIVE PLANT BIOLOGY 2022; 64:412-430. [PMID: 35029029 PMCID: PMC9255596 DOI: 10.1111/jipb.13222] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/30/2021] [Accepted: 01/10/2022] [Indexed: 05/20/2023]
Abstract
Cereal crops are significant contributors to global diets. As climate change disrupts weather patterns and wreaks havoc on crops, the need for generating stress-resilient, high-yielding varieties is more urgent than ever. One extremely promising avenue in this regard is to exploit the tremendous genetic diversity expressed by the wild ancestors of current day crop species. These crop wild relatives thrive in a range of environments and accordingly often harbor an array of traits that allow them to do so. The identification and introgression of these traits into our staple cereal crops can lessen yield losses in stressful environments. In the last decades, a surge in extreme drought and flooding events have severely impacted cereal crop production. Climate models predict a persistence of this trend, thus reinforcing the need for research on water stress resilience. Here we review: (i) how water stress (drought and flooding) impacts crop performance; and (ii) how identification of tolerance traits and mechanisms from wild relatives of the main cereal crops, that is, rice, maize, wheat, and barley, can lead to improved survival and sustained yields in these crops under water stress conditions.
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Affiliation(s)
- Justine M. Toulotte
- Department of Biology, Plant Ecophysiology, Institute of Environmental BiologyUtrecht UniversityUtrecht3584 CHThe Netherlands
| | - Chrysoula K. Pantazopoulou
- Department of Biology, Plant Ecophysiology, Institute of Environmental BiologyUtrecht UniversityUtrecht3584 CHThe Netherlands
| | - Maria Angelica Sanclemente
- Department of Biology, Plant Ecophysiology, Institute of Environmental BiologyUtrecht UniversityUtrecht3584 CHThe Netherlands
| | - Laurentius A. C. J. Voesenek
- Department of Biology, Plant Ecophysiology, Institute of Environmental BiologyUtrecht UniversityUtrecht3584 CHThe Netherlands
| | - Rashmi Sasidharan
- Department of Biology, Plant Ecophysiology, Institute of Environmental BiologyUtrecht UniversityUtrecht3584 CHThe Netherlands
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12
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Calfee E, Gates D, Lorant A, Perkins MT, Coop G, Ross-Ibarra J. Selective sorting of ancestral introgression in maize and teosinte along an elevational cline. PLoS Genet 2021; 17:e1009810. [PMID: 34634032 PMCID: PMC8530355 DOI: 10.1371/journal.pgen.1009810] [Citation(s) in RCA: 28] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2021] [Revised: 10/21/2021] [Accepted: 09/07/2021] [Indexed: 12/02/2022] Open
Abstract
While often deleterious, hybridization can also be a key source of genetic variation and pre-adapted haplotypes, enabling rapid evolution and niche expansion. Here we evaluate these opposing selection forces on introgressed ancestry between maize (Zea mays ssp. mays) and its wild teosinte relative, mexicana (Zea mays ssp. mexicana). Introgression from ecologically diverse teosinte may have facilitated maize's global range expansion, in particular to challenging high elevation regions (> 1500 m). We generated low-coverage genome sequencing data for 348 maize and mexicana individuals to evaluate patterns of introgression in 14 sympatric population pairs, spanning the elevational range of mexicana, a teosinte endemic to the mountains of Mexico. While recent hybrids are commonly observed in sympatric populations and mexicana demonstrates fine-scale local adaptation, we find that the majority of mexicana ancestry tracts introgressed into maize over 1000 generations ago. This mexicana ancestry seems to have maintained much of its diversity and likely came from a common ancestral source, rather than contemporary sympatric populations, resulting in relatively low FST between mexicana ancestry tracts sampled from geographically distant maize populations. Introgressed mexicana ancestry in maize is reduced in lower-recombination rate quintiles of the genome and around domestication genes, consistent with pervasive selection against introgression. However, we also find mexicana ancestry increases across the sampled elevational gradient and that high introgression peaks are most commonly shared among high-elevation maize populations, consistent with introgression from mexicana facilitating adaptation to the highland environment. In the other direction, we find patterns consistent with adaptive and clinal introgression of maize ancestry into sympatric mexicana at many loci across the genome, suggesting that maize also contributes to adaptation in mexicana, especially at the lower end of its elevational range. In sympatric maize, in addition to high introgression regions we find many genomic regions where selection for local adaptation maintains steep gradients in introgressed mexicana ancestry across elevation, including at least two inversions: the well-characterized 14 Mb Inv4m on chromosome 4 and a novel 3 Mb inversion Inv9f surrounding the macrohairless1 locus on chromosome 9. Most outlier loci with high mexicana introgression show no signals of sweeps or local sourcing from sympatric populations and so likely represent ancestral introgression sorted by selection, resulting in correlated but distinct outcomes of introgression in different contemporary maize populations.
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Affiliation(s)
- Erin Calfee
- Center for Population Biology, University of California, Davis, California, United States of America
- Department of Evolution and Ecology, University of California, Davis, California, United States of America
| | - Daniel Gates
- Department of Evolution and Ecology, University of California, Davis, California, United States of America
| | - Anne Lorant
- Department of Plant Sciences, University of California, Davis, California, United States of America
| | - M. Taylor Perkins
- Department of Evolution and Ecology, University of California, Davis, California, United States of America
| | - Graham Coop
- Center for Population Biology, University of California, Davis, California, United States of America
- Department of Evolution and Ecology, University of California, Davis, California, United States of America
| | - Jeffrey Ross-Ibarra
- Center for Population Biology, University of California, Davis, California, United States of America
- Department of Evolution and Ecology, University of California, Davis, California, United States of America
- Genome Center, University of California, Davis, California, United States of America
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13
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Morales-Cruz A, Aguirre-Liguori JA, Zhou Y, Minio A, Riaz S, Walker AM, Cantu D, Gaut BS. Introgression among North American wild grapes (Vitis) fuels biotic and abiotic adaptation. Genome Biol 2021; 22:254. [PMID: 34479604 PMCID: PMC8414701 DOI: 10.1186/s13059-021-02467-z] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2021] [Accepted: 08/12/2021] [Indexed: 01/27/2023] Open
Abstract
BACKGROUND Introgressive hybridization can reassort genetic variants into beneficial combinations, permitting adaptation to new ecological niches. To evaluate evolutionary patterns and dynamics that contribute to introgression, we investigate six wild Vitis species that are native to the Southwestern United States and useful for breeding grapevine (V. vinifera) rootstocks. RESULTS By creating a reference genome assembly from one wild species, V. arizonica, and by resequencing 130 accessions, we focus on identifying putatively introgressed regions (pIRs) between species. We find six species pairs with signals of introgression between them, comprising up to ~ 8% of the extant genome for some pairs. The pIRs tend to be gene poor, located in regions of high recombination and enriched for genes implicated in disease resistance functions. To assess potential pIR function, we explore SNP associations to bioclimatic variables and to bacterial levels after infection with the causative agent of Pierce's disease (Xylella fastidiosa). pIRs are enriched for SNPs associated with both climate and bacterial levels, suggesting that introgression is driven by adaptation to biotic and abiotic stressors. CONCLUSIONS Altogether, this study yields insights into the genomic extent of introgression, potential pressures that shape adaptive introgression, and the evolutionary history of economically important wild relatives of a critical crop.
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Affiliation(s)
- Abraham Morales-Cruz
- Department of Ecology and Evolutionary Biology, University of California Irvine, Irvine, CA USA
| | | | - Yongfeng Zhou
- Department of Ecology and Evolutionary Biology, University of California Irvine, Irvine, CA USA
| | - Andrea Minio
- Department of Viticulture and Enology, University of California, Davis, Davis, CA USA
| | - Summaira Riaz
- Department of Viticulture and Enology, University of California, Davis, Davis, CA USA
| | - Andrew M. Walker
- Department of Viticulture and Enology, University of California, Davis, Davis, CA USA
| | - Dario Cantu
- Department of Viticulture and Enology, University of California, Davis, Davis, CA USA
| | - Brandon S. Gaut
- Department of Ecology and Evolutionary Biology, University of California Irvine, Irvine, CA USA
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14
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Woodhouse MR, Cannon EK, Portwood JL, Harper LC, Gardiner JM, Schaeffer ML, Andorf CM. A pan-genomic approach to genome databases using maize as a model system. BMC PLANT BIOLOGY 2021; 21:385. [PMID: 34416864 PMCID: PMC8377966 DOI: 10.1186/s12870-021-03173-5] [Citation(s) in RCA: 76] [Impact Index Per Article: 25.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/28/2021] [Accepted: 08/11/2021] [Indexed: 05/21/2023]
Abstract
Research in the past decade has demonstrated that a single reference genome is not representative of a species' diversity. MaizeGDB introduces a pan-genomic approach to hosting genomic data, leveraging the large number of diverse maize genomes and their associated datasets to quickly and efficiently connect genomes, gene models, expression, epigenome, sequence variation, structural variation, transposable elements, and diversity data across genomes so that researchers can easily track the structural and functional differences of a locus and its orthologs across maize. We believe our framework is unique and provides a template for any genomic database poised to host large-scale pan-genomic data.
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Affiliation(s)
| | - Ethalinda K Cannon
- Corn Insects and Crop Genetics Research Unit, USDA-ARS, Ames, IA, 50011, USA
| | - John L Portwood
- Corn Insects and Crop Genetics Research Unit, USDA-ARS, Ames, IA, 50011, USA
| | - Lisa C Harper
- Corn Insects and Crop Genetics Research Unit, USDA-ARS, Ames, IA, 50011, USA
| | - Jack M Gardiner
- Division of Animal Sciences, University of Missouri, 65211, Columbia, MO, USA
| | - Mary L Schaeffer
- Division of Plant Sciences, University of Missouri, 65211, Columbia, MO, USA
| | - Carson M Andorf
- Corn Insects and Crop Genetics Research Unit, USDA-ARS, Ames, IA, 50011, USA
- Department of Computer Science, Iowa State University, Ames, IA, 50011, USA
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15
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Genetic diversity and selection signatures in maize landraces compared across 50 years of in situ and ex situ conservation. Heredity (Edinb) 2021; 126:913-928. [PMID: 33785893 PMCID: PMC8178342 DOI: 10.1038/s41437-021-00423-y] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2020] [Revised: 02/28/2021] [Accepted: 02/28/2021] [Indexed: 02/01/2023] Open
Abstract
Genomics-based, longitudinal comparisons between ex situ and in situ agrobiodiversity conservation strategies can contribute to a better understanding of their underlying effects. However, landrace designations, ambiguous common names, and gaps in sampling information complicate the identification of matching ex situ and in situ seed lots. Here we report a 50-year longitudinal comparison of the genetic diversity of a set of 13 accessions from the state of Morelos, Mexico, conserved ex situ since 1967 and retrieved in situ from the same donor families in 2017. We interviewed farmer families who donated in situ landraces to understand their germplasm selection criteria. Samples were genotyped by sequencing, producing 74,739 SNPs. Comparing the two sample groups, we show that ex situ and in situ genome-wide diversity was similar. In situ samples had 3.1% fewer SNPs and lower pairwise genetic distances (Fst 0.008-0.113) than ex situ samples (Fst 0.031-0.128), but displayed the same heterozygosity. Despite genome-wide similarities across samples, we could identify several loci under selection when comparing in situ and ex situ seed lots, suggesting ongoing evolution in farmer fields. Eight loci in chromosomes 3, 5, 6, and 10 showed evidence of selection in situ that could be related with farmers' selection criteria surveyed with focus groups and interviews at the sampling site in 2017, including wider kernels and larger ear size. Our results have implications for ex situ collection resampling strategies and the in situ conservation of threatened landraces.
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16
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A comparison of the direct and indirect defence abilities of cultivated maize versus perennial and annual teosintes. CHEMOECOLOGY 2020. [DOI: 10.1007/s00049-020-00329-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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17
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Adaptive introgression from maize has facilitated the establishment of teosinte as a noxious weed in Europe. Proc Natl Acad Sci U S A 2020; 117:25618-25627. [PMID: 32989136 DOI: 10.1073/pnas.2006633117] [Citation(s) in RCA: 42] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Global trade has considerably accelerated biological invasions. The annual tropical teosintes, the closest wild relatives of maize, were recently reported as new agricultural weeds in two European countries, Spain and France. Their prompt settlement under climatic conditions differing drastically from that of their native range indicates rapid genetic evolution. We performed a phenotypic comparison of French and Mexican teosintes under European conditions and showed that only the former could complete their life cycle during maize cropping season. To test the hypothesis that crop-to-wild introgression triggered such rapid adaptation, we used single nucleotide polymorphisms to characterize patterns of genetic variation in French, Spanish, and Mexican teosintes as well as in maize germplasm. We showed that both Spanish and French teosintes originated from Zea mays ssp. mexicana race "Chalco," a weedy teosinte from the Mexican highlands. However, introduced teosintes differed markedly from their Mexican source by elevated levels of genetic introgression from the high latitude Dent maize grown in Europe. We identified a clear signature of divergent selection in a region of chromosome 8 introgressed from maize and encompassing ZCN8, a major flowering time gene associated with adaptation to high latitudes. Moreover, herbicide assays and sequencing revealed that French teosintes have acquired herbicide resistance via the introgression of a mutant herbicide-target gene (ACC1) present in herbicide-resistant maize cultivars. Altogether, our results demonstrate that adaptive crop-to-wild introgression has triggered both rapid adaptation to a new climatic niche and acquisition of herbicide resistance, thereby fostering the establishment of an emerging noxious weed.
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18
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Baiakhmetov E, Nowak A, Gudkova PD, Nobis M. Morphological and genome-wide evidence for natural hybridisation within the genus Stipa (Poaceae). Sci Rep 2020; 10:13803. [PMID: 32796878 PMCID: PMC7427808 DOI: 10.1038/s41598-020-70582-1] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2020] [Accepted: 07/31/2020] [Indexed: 11/17/2022] Open
Abstract
Hybridisation in the wild between closely related species is a common mechanism of speciation in the plant kingdom and, in particular, in the grass family. Here we explore the potential for natural hybridisation in Stipa (one of the largest genera in Poaceae) between genetically distant species at their distribution edges in Mountains of Central Asia using integrative taxonomy. Our research highlights the applicability of classical morphological and genome reduction approaches in studies on wild plant species. The obtained results revealed a new nothospecies, Stipa × lazkovii, which exhibits intermediate characters to S. krylovii and S. bungeana. A high-density DArTseq assay disclosed that S. × lazkovii is an F1 hybrid, and established that the plastid and mitochondrial DNA was inherited from S. bungeana. In addition, molecular markers detected a hybridisation event between morphologically and genetically distant species S. bungeana and probably S. glareosa. Moreover, our findings demonstrated an uncertainty on the taxonomic status of S. bungeana that currently belongs to the section Leiostipa, but it is genetically closer to S. breviflora from the section Barbatae. Finally, we noticed a discrepancy between the current molecular data with the previous findings on S. capillata and S. sareptana.
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Affiliation(s)
- Evgenii Baiakhmetov
- Institute of Botany, Faculty of Biology, Jagiellonian University, Gronostajowa 3, 30-387, Kraków, Poland. .,Research Laboratory 'Herbarium', National Research Tomsk State University, Lenin 36 Ave, 634050, Tomsk, Russia.
| | - Arkadiusz Nowak
- Botanical Garden-Centre for Biological Diversity Conservation, Polish Academy of Sciences, Prawdziwka 2, 02-973, Warszawa, Poland.,Institute of Biology, Opole University, Oleska 22, 45-052, Opole, Poland
| | - Polina D Gudkova
- Research Laboratory 'Herbarium', National Research Tomsk State University, Lenin 36 Ave, 634050, Tomsk, Russia.,Department of Biology, Altai State University, Lenin 61 Ave, 656049, Barnaul, Russia
| | - Marcin Nobis
- Institute of Botany, Faculty of Biology, Jagiellonian University, Gronostajowa 3, 30-387, Kraków, Poland.
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19
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Moreno-Letelier A, Aguirre-Liguori JA, Piñero D, Vázquez-Lobo A, Eguiarte LE. The relevance of gene flow with wild relatives in understanding the domestication process. ROYAL SOCIETY OPEN SCIENCE 2020; 7:191545. [PMID: 32431864 PMCID: PMC7211868 DOI: 10.1098/rsos.191545] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/18/2019] [Accepted: 02/27/2020] [Indexed: 05/06/2023]
Abstract
The widespread use of genomic tools has allowed for a deeper understanding of the genetics and the evolutionary dynamics of domestication. Recent studies have suggested that multiple domestications and introgression are more common than previously thought. However, the ability to correctly infer the many aspects of domestication process depends on having an adequate representation of wild relatives. Cultivated maize (Zea mays ssp. mays) is one of the most important crops in the world, with a long and a relatively well-documented history of domestication. The current consensus points towards a single domestication event from teosinte Zea mays ssp. parviglumis from the Balsas Basin in Southwestern Mexico. However, the underlying diversity of teosintes from Z. mays ssp. parviglumis and Zea mays ssp. mexicana was not taken into account in early studies. We used 32 739 single nucleotide polymorphisms (SNPs) obtained from 29 teosinte populations and 43 maize landraces to explore the relationship between wild and cultivated members of Zea. We then inferred the levels of gene flow among teosinte populations and maize, the degree of population structure of Zea mays subspecies, and the potential domestication location of maize. We confirmed a strong geographic structure within Z. mays ssp. parviglumis and documented multiple gene flow events with other members of the genus, including an event between Z. mays ssp. mexicana and maize. Our results suggest that the likely ancestor of maize may have been domesticated in Jalisco or in the southern Pacific Coast and not in the Balsas Basin as previously thought. In this context, different populations of both teosinte subspecies have contributed to modern maize's gene pool. Our results point towards a long period of domestication marked by gene flow with wild relatives, confirming domestication as long and ongoing process.
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Affiliation(s)
- Alejandra Moreno-Letelier
- Jardín Botánico, Instituto de Biología, Universidad Nacional Autónoma de México, Ciudad de México, México
| | - Jonás A. Aguirre-Liguori
- Departamento de Ecología Evolutiva, Instituto de Ecología, Universidad Nacional Autónoma de México, Ciudad de México, México
| | - Daniel Piñero
- Departamento de Ecología Evolutiva, Instituto de Ecología, Universidad Nacional Autónoma de México, Ciudad de México, México
| | - Alejandra Vázquez-Lobo
- Centro de Investigación en Biodiversidad y Conservación, Universidad Autónoma del Estado de Morelos. Av. Universidad 1001 Cuernavaca, Morelos, 62209, México
| | - Luis E. Eguiarte
- Departamento de Ecología Evolutiva, Instituto de Ecología, Universidad Nacional Autónoma de México, Ciudad de México, México
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