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Abeyratne CR, Macaya-Sanz D, Zhou R, Barry KW, Daum C, Haiby K, Lipzen A, Stanton B, Yoshinaga Y, Zane M, Tuskan GA, DiFazio SP. High-resolution mapping reveals hotspots and sex-biased recombination in Populus trichocarpa. G3 (BETHESDA, MD.) 2023; 13:jkac269. [PMID: 36250890 PMCID: PMC9836356 DOI: 10.1093/g3journal/jkac269] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/10/2022] [Accepted: 09/28/2022] [Indexed: 12/14/2022]
Abstract
Fine-scale meiotic recombination is fundamental to the outcome of natural and artificial selection. Here, dense genetic mapping and haplotype reconstruction were used to estimate recombination for a full factorial Populus trichocarpa cross of 7 males and 7 females. Genomes of the resulting 49 full-sib families (N = 829 offspring) were resequenced, and high-fidelity biallelic SNP/INDELs and pedigree information were used to ascertain allelic phase and impute progeny genotypes to recover gametic haplotypes. The 14 parental genetic maps contained 1,820 SNP/INDELs on average that covered 376.7 Mb of physical length across 19 chromosomes. Comparison of parental and progeny haplotypes allowed fine-scale demarcation of cross-over regions, where 38,846 cross-over events in 1,658 gametes were observed. Cross-over events were positively associated with gene density and negatively associated with GC content and long-terminal repeats. One of the most striking findings was higher rates of cross-overs in males in 8 out of 19 chromosomes. Regions with elevated male cross-over rates had lower gene density and GC content than windows showing no sex bias. High-resolution analysis identified 67 candidate cross-over hotspots spread throughout the genome. DNA sequence motifs enriched in these regions showed striking similarity to those of maize, Arabidopsis, and wheat. These findings, and recombination estimates, will be useful for ongoing efforts to accelerate domestication of this and other biomass feedstocks, as well as future studies investigating broader questions related to evolutionary history, perennial development, phenology, wood formation, vegetative propagation, and dioecy that cannot be studied using annual plant model systems.
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Affiliation(s)
| | - David Macaya-Sanz
- Department of Forest Ecology & Genetics, CIFOR-INIA, CSIC, Madrid 28040, Spain
| | - Ran Zhou
- Warnell School of Forestry and Natural Resources, Department of Genetics, and Department of Plant Biology, University of Georgia, Athens, GA 30602, USA
| | - Kerrie W Barry
- Department of Energy Joint Genome Institute, Berkeley, CA 94720, USA
| | - Christopher Daum
- Department of Energy Joint Genome Institute, Berkeley, CA 94720, USA
| | | | - Anna Lipzen
- Department of Energy Joint Genome Institute, Berkeley, CA 94720, USA
| | | | - Yuko Yoshinaga
- Department of Energy Joint Genome Institute, Berkeley, CA 94720, USA
| | - Matthew Zane
- Department of Energy Joint Genome Institute, Berkeley, CA 94720, USA
| | - Gerald A Tuskan
- Biosciences Division, Center for Bioenergy Innovation, Oak Ridge National Laboratory, Oak Ridge, TN 37830, USA
| | - Stephen P DiFazio
- Department of Biology, West Virginia University, Morgantown, WV 26506, USA
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2
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Liu Y. Conservation prioritization based on past cascading climatic effects on genetic diversity and population size dynamics: Insights from a temperate tree species. DIVERS DISTRIB 2022. [DOI: 10.1111/ddi.13490] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Affiliation(s)
- Yang Liu
- Department of Forest and Conservation Sciences University of British Columbia Vancouver British Columbia Canada
- Department of Archaeology University of Cambridge Cambridge UK
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New developments in the field of genomic technologies and their relevance to conservation management. CONSERV GENET 2021. [DOI: 10.1007/s10592-021-01415-5] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
AbstractRecent technological advances in the field of genomics offer conservation managers and practitioners new tools to explore for conservation applications. Many of these tools are well developed and used by other life science fields, while others are still in development. Considering these technological possibilities, choosing the right tool(s) from the toolbox is crucial and can pose a challenging task. With this in mind, we strive to inspire, inform and illuminate managers and practitioners on how conservation efforts can benefit from the current genomic and biotechnological revolution. With inspirational case studies we show how new technologies can help resolve some of the main conservation challenges, while also informing how implementable the different technologies are. We here focus specifically on small population management, highlight the potential for genetic rescue, and discuss the opportunities in the field of gene editing to help with adaptation to changing environments. In addition, we delineate potential applications of gene drives for controlling invasive species. We illuminate that the genomic toolbox offers added benefit to conservation efforts, but also comes with limitations for the use of these novel emerging techniques.
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Klocko AL, Lu H, Magnuson A, Brunner AM, Ma C, Strauss SH. Phenotypic Expression and Stability in a Large-Scale Field Study of Genetically Engineered Poplars Containing Sexual Containment Transgenes. Front Bioeng Biotechnol 2018; 6:100. [PMID: 30123794 PMCID: PMC6085431 DOI: 10.3389/fbioe.2018.00100] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2018] [Accepted: 06/26/2018] [Indexed: 01/12/2023] Open
Abstract
Genetic engineering (GE) has the potential to help meet demand for forest products and ecological services. However, high research and development costs, market restrictions, and regulatory obstacles to performing field tests have severely limited the extent and duration of field research. There is a notable paucity of field studies of flowering GE trees due to the time frame required and regulatory constraints. Here we summarize our findings from field testing over 3,300 GE poplar trees and 948 transformation events in a single, 3.6 hectare field trial for seven growing seasons; this trial appears to be the largest field-based scientific study of GE forest trees in the world. The goal was to assess a diversity of approaches for obtaining bisexual sterility by modifying RNA expression or protein function of floral regulatory genes, including LEAFY, AGAMOUS, APETALA1, SHORT VEGETATIVE PHASE, and FLOWERING LOCUS T. Two female and one male clone were transformed with up to 23 different genetic constructs designed to obtain sterile flowers or delay onset of flowering. To prevent gene flow by pollen and facilitate regulatory approval, the test genotypes chosen were incompatible with native poplars in the area. We monitored tree survival, growth, floral onset, floral abundance, pollen production, seed formation and seed viability. Tree survival was above 95%, and variation in site conditions generally had a larger impact on vegetative performance and onset of flowering than did genetic constructs. Floral traits, when modified, were stable over three to five flowering seasons, and we successfully identified RNAi or overexpression constructs that either postponed floral onset or led to sterile flowers. There was an absence of detectable somaclonal variation; no trees were identified that showed vegetative or floral modifications that did not appear to be related to the transgene added. Surveys for seedling and sucker establishment both within and around the plantation identified small numbers of vegetative shoots (root sprouts) but no seedlings, indicative of a lack of establishment of trees via seeds in the area. Overall, this long term study showed that GE containment traits can be obtained which are effective, stable, and not associated with vegetative abnormalities or somaclonal variation.
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Affiliation(s)
| | | | | | | | | | - Steven H. Strauss
- Department of Forest Ecosystems and Society, Oregon State University, Corvallis, OR, United States
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Pan Y, Chu J, Yang H. Conservation choice on the rare endangered plants Glehnia littoralis. CONSERVATION PHYSIOLOGY 2018; 6:coy002. [PMID: 29399363 PMCID: PMC5788067 DOI: 10.1093/conphys/coy002] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/30/2017] [Revised: 11/26/2017] [Accepted: 01/07/2018] [Indexed: 06/07/2023]
Abstract
The coastal herbs Glehnia littoralis have been domesticated as traditional medicines for many centuries. The domestication may have caused changes or declines of cultivated G. littoralis (CGL) relative to wild G. littoralis (WGL). By comparing fruit properties of CGL and WGL, we tested the hypothesis that domesticated G. littoralis have suffered major declines, and human cultivation cannot be sufficient to conserve this species. We collected fruits of CGL and WGL in the Shandong peninsula, China, and compared their buoyancy in seawater, germination potential after seawater immersion, and thousand-grain weights. Float rates of the WGL and CGL fruits were 95.6 (mean) ± 2.6% (standard deviation) and 30.0 ± 7.1%, respectively. The germination potential of CGL was significantly reduced, although the thousand-grain weights of CGL (21.85 ± 0.17 g) were higher than those of the WGL fruits (14.73 ± 0.21 g). These results suggest that the CGL have experienced significant declines relative to the WGL, presumably due to the loss of seawater inundation, selection and dispersal. These declines disfavour the persistence of CGL, and human domestication and cultivation are believed to be insufficient for conserving G. littoralis. Sand coasts where WGL still persists should be designated timely as nature reserves to conserve this species.
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Affiliation(s)
- Yanxia Pan
- Qingdao Agricultural University, Changcheng Road, Chengyang, Qingdao, Shandong Province 266109, China
| | - Jianmin Chu
- Key Laboratory of Tree Breeding and Cultivation, State Forestry Administration, Research Institute of Forestry, Chinese Academy of Forestry, Beijing 100091, China
| | - Hongxiao Yang
- Qingdao Agricultural University, Changcheng Road, Chengyang, Qingdao, Shandong Province 266109, China
- Qingdao Engineering Research Center for Rural Environment, Chengyang, Qingdao, Shandong Province 266109, China
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Semizer-Cuming D, Kjær ED, Finkeldey R. Gene flow of common ash (Fraxinus excelsior L.) in a fragmented landscape. PLoS One 2017; 12:e0186757. [PMID: 29053740 PMCID: PMC5650178 DOI: 10.1371/journal.pone.0186757] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2017] [Accepted: 10/06/2017] [Indexed: 12/24/2022] Open
Abstract
Gene flow dynamics of common ash (Fraxinus excelsior L.) is affected by several human activities in Central Europe, including habitat fragmentation, agroforestry expansion, controlled and uncontrolled transfer of reproductive material, and a recently introduced emerging infectious disease, ash dieback, caused by Hymenoscyphus fraxineus. Habitat fragmentation may alter genetic connectivity and effective population size, leading to loss of genetic diversity and increased inbreeding in ash populations. Gene flow from cultivated trees in landscapes close to their native counterparts may also influence the adaptability of future generations. The devastating effects of ash dieback have already been observed in both natural and managed populations in continental Europe. However, potential long-term effects of genetic bottlenecks depend on gene flow across fragmented landscapes. For this reason, we studied the genetic connectivity of ash trees in an isolated forest patch of a fragmented landscape in Rösenbeck, Germany. We applied two approaches to parentage analysis to estimate gene flow patterns at the study site. We specifically investigated the presence of background pollination at the landscape level and the degree of genetic isolation between native and cultivated trees. Local meteorological data was utilized to understand the effect of wind on the pollen and seed dispersal patterns. Gender information of the adult trees was considered for calculating the dispersal distances. We found that the majority of the studied seeds (55-64%) and seedlings (75-98%) in the forest patch were fathered and mothered by the trees within the same patch. However, we determined a considerable amount of pollen flow (26-45%) from outside of the study site, representing background pollination at the landscape level. Limited pollen flow was observed from neighbouring cultivated trees (2%). Both pollen and seeds were dispersed in all directions in accordance with the local wind directions. Whereas there was no positive correlation between pollen dispersal distance and wind speed, the correlation between seed dispersal distance and wind speed was significant (0.71, p < 0.001), indicating that strong wind favours long-distance dispersal of ash seeds. Finally, we discussed the implications of establishing gene conservation stands and the use of enrichment planting in the face of ash dieback.
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Affiliation(s)
- Devrim Semizer-Cuming
- Department of Forest Genetics and Forest Tree Breeding, Faculty of Forest Sciences and Forest Ecology, University of Göttingen, Göttingen, Germany
- Department of Geosciences and Natural Resource Management, University of Copenhagen, Copenhagen, Denmark
| | - Erik Dahl Kjær
- Department of Geosciences and Natural Resource Management, University of Copenhagen, Copenhagen, Denmark
| | - Reiner Finkeldey
- Department of Forest Genetics and Forest Tree Breeding, Faculty of Forest Sciences and Forest Ecology, University of Göttingen, Göttingen, Germany
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7
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Strauss SH, Jones KN, Lu H, Petit JD, Klocko AL, Betts MG, Brosi BJ, Fletcher RJ, Needham MD. Reproductive modification in forest plantations: impacts on biodiversity and society. THE NEW PHYTOLOGIST 2017; 213:1000-1021. [PMID: 28079940 DOI: 10.1111/nph.14374] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/17/2016] [Accepted: 10/26/2016] [Indexed: 05/20/2023]
Abstract
1000 I. 1000 II. 1001 III. 1014 IV. 1015 V. 1016 1016 References 1016 SUMMARY: Genetic engineering (GE) can be used to improve forest plantation productivity and tolerance of biotic and abiotic stresses. However, gene flow from GE forest plantations is a large source of ecological, social and legal controversy. The use of genetic technologies to mitigate or prevent gene flow has been discussed widely and should be technically feasible in a variety of plantation taxa. However, potential ecological effects of such modifications, and their social acceptability, are not well understood. Focusing on Eucalyptus, Pinus, Populus and Pseudotsuga - genera that represent diverse modes of pollination and seed dispersal - we conducted in-depth reviews of ecological processes associated with reproductive tissues. We also explored potential impacts of various forms of reproductive modification at stand and landscape levels, and means for mitigating impacts. We found little research on potential reactions by the public and other stakeholders to reproductive modification in forest plantations. However, there is considerable research on related areas that suggest key dimensions of concern and support. We provide detailed suggestions for research to understand the biological and social dimensions of containment technologies, and consider the role of regulatory and market restrictions that obstruct necessary ecological and genetic research.
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Affiliation(s)
- Steven H Strauss
- Department of Forest Ecosystems and Society, Oregon State University, Corvallis, OR, 97331, USA
| | - Kristin N Jones
- Department of Forest Ecosystems and Society, Oregon State University, Corvallis, OR, 97331, USA
| | - Haiwei Lu
- Department of Forest Ecosystems and Society, Oregon State University, Corvallis, OR, 97331, USA
| | - Joshua D Petit
- Department of Forest Ecosystems and Society, Oregon State University, Corvallis, OR, 97331, USA
| | - Amy L Klocko
- Department of Forest Ecosystems and Society, Oregon State University, Corvallis, OR, 97331, USA
| | - Matthew G Betts
- Forest Biodiversity Research Network, Department of Forest Ecosystems and Society, Oregon State University, Corvallis, OR, 97331, USA
| | - Berry J Brosi
- Department of Environmental Sciences, Emory University, Atlanta, GA, 30322, USA
| | - Robert J Fletcher
- Department of Wildlife Ecology and Conservation, University of Florida, Gainesville, FL, 32611, USA
| | - Mark D Needham
- Department of Forest Ecosystems and Society, Oregon State University, Corvallis, OR, 97331, USA
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8
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Hu J, Zhang J, Chen X, Lv J, Jia H, Zhao S, Lu M. An Empirical Assessment of Transgene Flow from a Bt Transgenic Poplar Plantation. PLoS One 2017; 12:e0170201. [PMID: 28085955 PMCID: PMC5234794 DOI: 10.1371/journal.pone.0170201] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2016] [Accepted: 01/01/2017] [Indexed: 11/18/2022] Open
Abstract
To assess the possible impact of transgenic poplar plantations on the ecosystem, we analyzed the frequency and distance of gene flow from a mature male transgenic Populus nigra plantation carrying the Bacillus thuringiensis toxin gene (Bt poplar) and the survival of Bt poplar seeds. The resultant Bt poplar seeds occurred at a frequency of ~0.15% at 0 m to ~0.02% at 500 m from the Bt poplar plantation. The germination of Bt poplar seeds diminished within three weeks in the field (germination rate from 68% to 0%) compared to 48% after three weeks of storage at 4°C. The survival rate of seedlings in the field was 0% without any treatment but increased to 1.7% under the addition of four treatments (cleaning and trimming, watering, weeding, and covering with plastic film to maintain moisture) after being seeded in the field for eight weeks. The results of this study indicate that gene flow originating from the Bt poplar plantation occurred at an extremely low level through pollen or seeds under natural conditions. This study provides first-hand field data on the extent of transgene flow in poplar plantations and offers guidance for the risk assessment of transgenic poplar plantations.
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Affiliation(s)
- Jianjun Hu
- State Key Laboratory of Tree Genetics and Breeding, Key Laboratory of Tree Breeding and Cultivation of State Forestry Administration, Research Institute of Forestry, Chinese Academy of Forestry, Beijing, China
- Collaborative Innovation Center of Sustainable Forestry in Southern China, Nanjing Forestry University, Nanjing, China
| | - Jin Zhang
- State Key Laboratory of Tree Genetics and Breeding, Key Laboratory of Tree Breeding and Cultivation of State Forestry Administration, Research Institute of Forestry, Chinese Academy of Forestry, Beijing, China
- Collaborative Innovation Center of Sustainable Forestry in Southern China, Nanjing Forestry University, Nanjing, China
| | | | - Jinhui Lv
- State Key Laboratory of Tree Genetics and Breeding, Key Laboratory of Tree Breeding and Cultivation of State Forestry Administration, Research Institute of Forestry, Chinese Academy of Forestry, Beijing, China
| | - Huixia Jia
- State Key Laboratory of Tree Genetics and Breeding, Key Laboratory of Tree Breeding and Cultivation of State Forestry Administration, Research Institute of Forestry, Chinese Academy of Forestry, Beijing, China
- Collaborative Innovation Center of Sustainable Forestry in Southern China, Nanjing Forestry University, Nanjing, China
| | - Shutang Zhao
- State Key Laboratory of Tree Genetics and Breeding, Key Laboratory of Tree Breeding and Cultivation of State Forestry Administration, Research Institute of Forestry, Chinese Academy of Forestry, Beijing, China
- Collaborative Innovation Center of Sustainable Forestry in Southern China, Nanjing Forestry University, Nanjing, China
| | - Mengzhu Lu
- State Key Laboratory of Tree Genetics and Breeding, Key Laboratory of Tree Breeding and Cultivation of State Forestry Administration, Research Institute of Forestry, Chinese Academy of Forestry, Beijing, China
- Collaborative Innovation Center of Sustainable Forestry in Southern China, Nanjing Forestry University, Nanjing, China
- * E-mail:
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9
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Landscape Genomics of Angiosperm Trees: From Historic Roots to Discovering New Branches of Adaptive Evolution. COMPARATIVE AND EVOLUTIONARY GENOMICS OF ANGIOSPERM TREES 2017. [DOI: 10.1007/7397_2016_19] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
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10
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Li W, Hu W, Fang C, Chen L, Zhuang W, Katin‐Grazzini L, McAvoy RJ, Guillard K, Li Y. An AGAMOUS intron-driven cytotoxin leads to flowerless tobacco and produces no detrimental effects on vegetative growth of either tobacco or poplar. PLANT BIOTECHNOLOGY JOURNAL 2016; 14:2276-2287. [PMID: 27168170 PMCID: PMC5103258 DOI: 10.1111/pbi.12581] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/12/2016] [Revised: 05/01/2016] [Accepted: 05/04/2016] [Indexed: 05/22/2023]
Abstract
Flowerless trait is highly desirable for poplar because it can prevent pollen- and seed-mediated transgene flow. We have isolated the second intron of PTAG2, an AGAMOUS (AG) orthologue from Populus trichocarpa. By fusing this intron sequence to a minimal 35S promoter sequence, we created two artificial promoters, fPTAG2I (forward orientation of the PTAG2 intron sequence) and rPTAG2I (reverse orientation of the PTAG2 intron sequence). In tobacco, expression of the β-glucuronidase gene (uidA) demonstrates that the fPTAG2I promoter is non-floral-specific, while the rPTAG2I promoter is active in floral buds but with no detectable vegetative activity. Under glasshouse conditions, transgenic tobacco plants expressing the Diphtheria toxin A (DT-A) gene driven by the rPTAG2I promoter produced three floral ablation phenotypes: flowerless, neuter (stamenless and carpel-less) and carpel-less. Further, the vegetative growth of these transgenic lines was similar to that of the wild-type plants. In field trials during 2014 and 2015, the flowerless transgenic tobacco stably maintained its flowerless phenotype, and also produced more shoot and root biomass when compared to wild-type plants. In poplar, the rPTAG2I::GUS gene exhibited no detectable activity in vegetative organs. Under field conditions over two growing seasons (2014 to the end of 2015), vegetative growth of the rPTAG2I::DT-A transgenic poplar plants was similar to that of the wild-type plants. Our results demonstrate that the rPTAG2I artificial promoter has no detectable activities in vegetative tissues and organs, and the rPTAG2I::DT-A gene may be useful for producing flowerless poplar that retains normal vegetative growth.
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Affiliation(s)
- Wei Li
- Department of Plant Science and Landscape ArchitectureUniversity of ConnecticutStorrsCTUSA
| | - Wei Hu
- Department of Plant Science and Landscape ArchitectureUniversity of ConnecticutStorrsCTUSA
| | - Chu Fang
- Department of Plant Science and Landscape ArchitectureUniversity of ConnecticutStorrsCTUSA
| | - Longzheng Chen
- Department of Plant Science and Landscape ArchitectureUniversity of ConnecticutStorrsCTUSA
- Institute of Vegetable CropsJiangsu Academy of Agricultural SciencesNanjingChina
| | - Weibing Zhuang
- Department of Plant Science and Landscape ArchitectureUniversity of ConnecticutStorrsCTUSA
- College of Horticulture and State Key Laboratory of Crop Genetics and Germplasm EnhancementNanjing Agricultural UniversityNanjingChina
| | - Lorenzo Katin‐Grazzini
- Department of Plant Science and Landscape ArchitectureUniversity of ConnecticutStorrsCTUSA
| | - Richard J. McAvoy
- Department of Plant Science and Landscape ArchitectureUniversity of ConnecticutStorrsCTUSA
| | - Karl Guillard
- Department of Plant Science and Landscape ArchitectureUniversity of ConnecticutStorrsCTUSA
| | - Yi Li
- Department of Plant Science and Landscape ArchitectureUniversity of ConnecticutStorrsCTUSA
- College of Horticulture and State Key Laboratory of Crop Genetics and Germplasm EnhancementNanjing Agricultural UniversityNanjingChina
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12
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Brundu G, Richardson DM. Planted forests and invasive alien trees in Europe: A Code for managing existing and future plantings to mitigate the risk of negative impacts from invasions. NEOBIOTA 2016. [DOI: 10.3897/neobiota.30.7015] [Citation(s) in RCA: 100] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
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13
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Dong S, Liu Y, Yu C, Zhang Z, Chen M, Wang C. Investigating Pollen and Gene Flow of WYMV-Resistant Transgenic Wheat N12-1 Using a Dwarf Male-Sterile Line as the Pollen Receptor. PLoS One 2016; 11:e0151373. [PMID: 26975052 PMCID: PMC4790897 DOI: 10.1371/journal.pone.0151373] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2015] [Accepted: 02/27/2016] [Indexed: 12/01/2022] Open
Abstract
Pollen-mediated gene flow (PMGF) is the main mode of transgene flow in flowering plants. The study of pollen and gene flow of transgenic wheat can help to establish the corresponding strategy for preventing transgene escape and contamination between compatible genotypes in wheat. To investigate the pollen dispersal and gene flow frequency in various directions and distances around the pollen source and detect the association between frequency of transgene flow and pollen density from transgenic wheat, a concentric circle design was adopted to conduct a field experiment using transgenic wheat with resistance to wheat yellow mosaic virus (WYMV) as the pollen donor and dwarf male-sterile wheat as the pollen receptor. The results showed that the pollen and gene flow of transgenic wheat varied significantly among the different compass sectors. A higher pollen density and gene flow frequency was observed in the downwind SW and W sectors, with average frequencies of transgene flow of 26.37 and 23.69% respectively. The pollen and gene flow of transgenic wheat declined dramatically with increasing distance from its source. Most of the pollen grains concentrated within 5 m and only a few pollen grains were detected beyond 30 m. The percentage of transgene flow was the highest where adjacent to the pollen source, with an average of 48.24% for all eight compass directions at 0 m distance. Transgene flow was reduced to 50% and 95% between 1.61 to 3.15 m, and 10.71 to 20.93 m, respectively. Our results suggest that climate conditions, especially wind direction, may significantly affect pollen dispersal and gene flow of wheat. The isolation-by-distance model is one of the most effective methods for achieving stringent transgene confinement in wheat. The frequency of transgene flow is directly correlated with the relative density of GM pollen grains in air currents, and pollen competition may be a major factor influencing transgene flow.
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Affiliation(s)
- Shanshan Dong
- Nanjing Institute of Environmental Sciences, Ministry of Environmental Protection, Nanjing, China
- Key Laboratory on Biosafety of Environmental Protection, Ministry of Environmental Protection, Nanjing, China
| | - Yan Liu
- Nanjing Institute of Environmental Sciences, Ministry of Environmental Protection, Nanjing, China
- Key Laboratory on Biosafety of Environmental Protection, Ministry of Environmental Protection, Nanjing, China
| | - Cigang Yu
- Nanjing Institute of Environmental Sciences, Ministry of Environmental Protection, Nanjing, China
- Key Laboratory on Biosafety of Environmental Protection, Ministry of Environmental Protection, Nanjing, China
| | - Zhenhua Zhang
- Nanjing Institute of Environmental Sciences, Ministry of Environmental Protection, Nanjing, China
- Key Laboratory on Biosafety of Environmental Protection, Ministry of Environmental Protection, Nanjing, China
| | - Ming Chen
- Key Laboratory of Biology and Genetic Improvement of Triticeae Crops, Institute of Crop Sciences, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Changyong Wang
- Nanjing Institute of Environmental Sciences, Ministry of Environmental Protection, Nanjing, China
- Key Laboratory on Biosafety of Environmental Protection, Ministry of Environmental Protection, Nanjing, China
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Huang J, Smith AR, Zhang T, Zhao D. Creating Completely Both Male and Female Sterile Plants by Specifically Ablating Microspore and Megaspore Mother Cells. FRONTIERS IN PLANT SCIENCE 2016; 7:30. [PMID: 26870055 PMCID: PMC4740954 DOI: 10.3389/fpls.2016.00030] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/21/2015] [Accepted: 01/10/2016] [Indexed: 05/20/2023]
Abstract
Although genetically modified (GM) plants have improved commercially important traits, such as biomass and biofuel production, digestibility, bioremediation, ornamental value, and tolerance to biotic and abiotic stresses, there remain economic, political, or social concerns over potential ecological effects of transgene flow from GM plants. The current solution for preventing transgene flow from GM plants is genetically engineering sterility; however, approaches to generating both male and female sterility are limited. In addition, existing strategies for creating sterility lead to loss or modifications of entire flowers or floral organs. Here, we demonstrate that instead of the 1.5-kb promoter, the entire SOLO DANCERS (SDS) gene is required for its meiocyte-specific expression. We then developed an efficient method to specifically ablate microspore and megaspore mother cells using the SDS and BARNASE fusion gene, which resulted in complete sterility in both male and female reproductive organs in Arabidopsis (Arabidopsis thaliana) and tobacco (Nicotiana tabacum), but did not affect plant growth or development, including the formation of all flower organs. Therefore, our research provides a general and effective tool to prevent transgene flow in GM plants.
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15
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Gressel J. Dealing with transgene flow of crop protection traits from crops to their relatives. PEST MANAGEMENT SCIENCE 2015; 71:658-667. [PMID: 24977384 DOI: 10.1002/ps.3850] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/12/2014] [Revised: 06/22/2014] [Accepted: 06/24/2014] [Indexed: 06/03/2023]
Abstract
Genes regularly move within species, to/from crops, as well as to their con- specific progenitors, feral and weedy forms ('vertical' gene flow). Genes occasionally move to/from crops and their distantly related, hardly sexually interbreeding relatives, within a genus or among closely related genera (diagonal gene flow). Regulators have singled out transgene flow as an issue, yet non-transgenic herbicide resistance traits pose equal problems, which cannot be mitigated. The risks are quite different from genes flowing to natural (wild) ecosystems versus ruderal and agroecosystems. Transgenic herbicide resistance poses a major risk if introgressed into weedy relatives; disease and insect resistance less so. Technologies have been proposed to contain genes within crops (chloroplast transformation, male sterility) that imperfectly prevent gene flow by pollen to the wild. Containment does not prevent related weeds from pollinating crops. Repeated backcrossing with weeds as pollen parents results in gene establishment in the weeds. Transgenic mitigation relies on coupling crop protection traits in a tandem construct with traits that lower the fitness of the related weeds. Mitigation traits can be morphological (dwarfing, no seed shatter) or chemical (sensitivity to a chemical used later in a rotation). Tandem mitigation traits are genetically linked and will move together. Mitigation traits can also be spread by inserting them in multicopy transposons which disperse faster than the crop protection genes in related weeds. Thus, there are gene flow risks mainly to weeds from some crop protection traits; risks that can and should be dealt with.
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Lagache L, Klein EK, Ducousso A, Petit RJ. Distinct male reproductive strategies in two closely related oak species. Mol Ecol 2014; 23:4331-43. [DOI: 10.1111/mec.12766] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2013] [Revised: 03/12/2014] [Accepted: 04/08/2014] [Indexed: 11/30/2022]
Affiliation(s)
- Lélia Lagache
- INRA; UMR 1202 Biogeco; F-33610 Cestas France
- Univ. Bordeaux; UMR1202 Biogeco; F-33400 Talence France
| | - Etienne K. Klein
- Biostatistique et Processus Spatiaux (BioSP); INRA; UR546; F-84914 Avignon France
| | - Alexis Ducousso
- INRA; UMR 1202 Biogeco; F-33610 Cestas France
- Univ. Bordeaux; UMR1202 Biogeco; F-33400 Talence France
| | - Rémy J. Petit
- INRA; UMR 1202 Biogeco; F-33610 Cestas France
- Univ. Bordeaux; UMR1202 Biogeco; F-33400 Talence France
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Roe AD, MacQuarrie CJK, Gros-Louis MC, Simpson JD, Lamarche J, Beardmore T, Thompson SL, Tanguay P, Isabel N. Fitness dynamics within a poplar hybrid zone: II. Impact of exotic sex on native poplars in an urban jungle. Ecol Evol 2014; 4:1876-89. [PMID: 24963382 PMCID: PMC4063481 DOI: 10.1002/ece3.1028] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2013] [Revised: 12/20/2013] [Accepted: 12/31/2013] [Indexed: 01/11/2023] Open
Abstract
Trees bearing novel or exotic gene components are poised to contribute to the bioeconomy for a variety of purposes such as bioenergy production, phytoremediation, and carbon sequestration within the forestry sector, but sustainable release of trees with novel traits in large-scale plantations requires the quantification of risks posed to native tree populations. Over the last century, exotic hybrid poplars produced through artificial crosses were planted throughout eastern Canada as ornamentals or windbreaks and these exotics provide a proxy by which to examine the fitness of exotic poplar traits within the natural environment to assess risk of exotic gene escape, establishment, and spread into native gene pools. We assessed postzygotic fitness traits of native and exotic poplars within a naturally regenerated stand in eastern Canada (Quebec City, QC). Pure natives (P. balsamifera and P. deltoides spp. deltoides), native hybrids (P. deltoides × P. balsamifera), and exotic hybrids (trees bearing Populus nigra and P. maximowiczii genetic components) were screened for reproductive biomass, yield, seed germination, and fungal disease susceptibility. Exotic hybrids expressed fitness traits intermediate to pure species and were not significantly different from native hybrids. They formed fully viable seed and backcrossed predominantly with P. balsamifera. These data show that exotic hybrids were not unfit and were capable of establishing and competing within the native stand. Future research will seek to examine the impact of exotic gene regions on associated biotic communities to fully quantify the risk exotic poplars pose to native poplar forests.
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Affiliation(s)
- Amanda D Roe
- Natural Resources Canada, Canadian Forest ServiceQuébec, Québec, Canada
- Natural Resources Canada, Canadian Forest ServiceSault Ste. Marie, Ontario, Canada
| | - Chris JK MacQuarrie
- Natural Resources Canada, Canadian Forest ServiceSault Ste. Marie, Ontario, Canada
| | | | - J Dale Simpson
- Natural Resources Canada, Canadian Forest ServiceFredericton, New-Brunswick, Canada
| | - Josyanne Lamarche
- Natural Resources Canada, Canadian Forest ServiceSault Ste. Marie, Ontario, Canada
| | - Tannis Beardmore
- Natural Resources Canada, Canadian Forest ServiceFredericton, New-Brunswick, Canada
| | - Stacey L Thompson
- Natural Resources Canada, Canadian Forest ServiceQuébec, Québec, Canada
- Umeå University, Department of Ecology and Environmental Science, Umeå Plant Science CentreUmeå, Sweden
| | - Philippe Tanguay
- Natural Resources Canada, Canadian Forest ServiceQuébec, Québec, Canada
| | - Nathalie Isabel
- Natural Resources Canada, Canadian Forest ServiceQuébec, Québec, Canada
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Thomasset M, Hodkinson TR, Restoux G, Frascaria-Lacoste N, Douglas GC, Fernández-Manjarrés JF. Thank you for not flowering: conservation genetics and gene flow analysis of native and non-native populations of Fraxinus (Oleaceae) in Ireland. Heredity (Edinb) 2014; 112:596-606. [PMID: 24424162 DOI: 10.1038/hdy.2013.141] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2012] [Revised: 09/02/2013] [Accepted: 11/22/2013] [Indexed: 11/09/2022] Open
Abstract
The risks of gene flow between interfertile native and introduced plant populations are greatest when there is no spatial isolation of pollen clouds and phenological patterns overlap completely. Moreover, invasion probabilities are further increased if introduced populations are capable of producing seeds by selfing. Here we investigated the mating system and patterns of pollen-mediated gene flow among populations of native ash (Fraxinus excelsior) and mixed plantations of non-native ash (F. angustifolia and F. excelsior) as well as hybrid ash (F. excelsior × F. angustifolia) in Ireland. We analysed the flowering phenology of the mother trees and genotyped with six microsatellite loci in progeny arrays from 132 native and plantation trees (1493 seeds) and 444 potential parents. Paternity analyses suggested that plantation and native trees were pollinated by both native and introduced trees. No signs of significant selfing in the introduced trees were observed and no evidence of higher male reproductive success was found for introduced trees compared with native ones either. A small but significant genetic structure was found (φft=0.05) and did not correspond to an isolation-by-distance pattern. However, we observed a significant temporal genetic structure related to the different phenological groups, especially with early and late flowering native trees; each phenological group was pollinated with distinctive pollen sources. Implications of these results are discussed in relation to the conservation and invasiveness of ash and the spread of resistance genes against pathogens such as the fungus Chalara fraxinea that is destroying common ash forests in Europe.
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Affiliation(s)
- M Thomasset
- 1] School of Natural Sciences, Trinity College Dublin, Dublin, Ireland [2] Teagasc, Kinsealy Research Centre, Dublin, Ireland
| | - T R Hodkinson
- 1] School of Natural Sciences, Trinity College Dublin, Dublin, Ireland [2] Trinity Centre for Biodiversity Research, Trinity College Dublin, Dublin, Ireland
| | - G Restoux
- Laboratoire d'Ecologie Systématique et Evolution, UMR 8079, Université Paris-Sud, Orsay, France
| | - N Frascaria-Lacoste
- 1] Laboratoire d'Ecologie Systématique et Evolution, UMR 8079, Université Paris-Sud, Orsay, France [2] AgroParisTech, Paris, France [3] CNRS, UMR 8079, Orsay, France
| | - G C Douglas
- Teagasc, Kinsealy Research Centre, Dublin, Ireland
| | - J F Fernández-Manjarrés
- 1] Laboratoire d'Ecologie Systématique et Evolution, UMR 8079, Université Paris-Sud, Orsay, France [2] AgroParisTech, Paris, France [3] CNRS, UMR 8079, Orsay, France
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Scientific Research Related to Genetically Modified Trees. CHALLENGES AND OPPORTUNITIES FOR THE WORLD'S FORESTS IN THE 21ST CENTURY 2014. [DOI: 10.1007/978-94-007-7076-8_22] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
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20
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Ellstrand NC, Meirmans P, Rong J, Bartsch D, Ghosh A, de Jong TJ, Haccou P, Lu BR, Snow AA, Neal Stewart C, Strasburg JL, van Tienderen PH, Vrieling K, Hooftman D. Introgression of Crop Alleles into Wild or Weedy Populations. ANNUAL REVIEW OF ECOLOGY EVOLUTION AND SYSTEMATICS 2013. [DOI: 10.1146/annurev-ecolsys-110512-135840] [Citation(s) in RCA: 149] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Norman C. Ellstrand
- Department of Botany and Plant Sciences, University of California, Riverside, California 92521;
| | - Patrick Meirmans
- Instituut voor Biodiversiteit en Ecosysteem Dynamica, Universiteit van Amsterdam, 1098 XH Amsterdam, The Netherlands;
| | - Jun Rong
- Center for Watershed Ecology, Institute of Life Science and Key Laboratory of Poyang Lake Environment and Resource Utilization, Ministry of Education, Nanchang University, 330031 Honggutan Nanchang, People's Republic of China;
| | - Detlef Bartsch
- Federal Office of Consumer Protection and Food Safety, 10117 Berlin, Germany;
| | - Atiyo Ghosh
- Integrative Systems Biology, Okinawa Institute of Science and Technology, Okinawa 904-0495, Japan;
| | - Tom J. de Jong
- Institute of Biology, Leiden University, 2333 BE Leiden, The Netherlands; ,
| | - Patsy Haccou
- Leiden University College The Hague, Leiden University, 2514 EG The Hague, The Netherlands;
| | - Bao-Rong Lu
- Ministry of Education Key Laboratory for Biodiversity and Ecological Engineering, Department of Ecology and Evolutionary Biology, Fudan University, Shanghai 200433, People's Republic of China; ,
| | - Allison A. Snow
- Department of Evolution, Ecology, and Organismal Biology, The Ohio State University, Columbus, Ohio 43210;
| | - C. Neal Stewart
- Department of Plant Sciences, University of Tennessee, Knoxville, Tennessee 37996;
| | | | - Peter H. van Tienderen
- Instituut voor Biodiversiteit en Ecosysteem Dynamica, Universiteit van Amsterdam, 1090 GE Amsterdam, The Netherlands;
| | - Klaas Vrieling
- Institute of Biology, Leiden University, 2333 BE Leiden, The Netherlands; ,
| | - Danny Hooftman
- Center for Ecology and Hydrology, National Environmental Research Council, Wallingford, Oxfordshire OX10 8BB, United Kingdom;
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Zhao X, Tang T, Chen G, Liu F, Wang X, Bu C, Lu C. Rationalizing the isolation distance needed for field trials involving genetically modified rapeseed (Brassica napus L.) in China. ACTA ACUST UNITED AC 2012. [DOI: 10.1007/s11434-012-5595-z] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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Lagache L, Klein EK, Guichoux E, Petit RJ. Fine-scale environmental control of hybridization in oaks. Mol Ecol 2012; 22:423-36. [PMID: 23173566 DOI: 10.1111/mec.12121] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2012] [Revised: 08/31/2012] [Accepted: 09/11/2012] [Indexed: 12/14/2022]
Abstract
Natural hybridization is attracting much interest in modern speciation and conservation biology studies, but the underlying mechanisms remain poorly understood. In particular, it is unclear why environmental changes often increase hybridization rates. To study this question, we surveyed mating events in a mixed oak stand and developed a spatially explicit individual-based hybridization model. This model, where hybridization is frequency-dependent, pollen is nonlimiting and which allows immigrant pollen to compete with local pollen, takes into account species-specific pollen dispersal and sexual barriers to hybridization. The consequences of pollen limitation on hybridization were studied using another simple model. The results indicate that environmental changes could increase hybridization rates through two distinct mechanisms. First, by disrupting the spatial organization of communities, they should decrease the proportion of conspecific pollen available for mating, thus increasing hybridization rates. Second, by decreasing the density of conspecifics, they should increase pollen limitation and thus hybridization rates, as a consequence of chance pollination predominating over deterministic pollen competition. Altogether, our results point to a need for considering hybridization events at the appropriate level of organization and provide new insights into why hybridization rates generally increase in disturbed environments.
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Affiliation(s)
- Lélia Lagache
- INRA, UMR1202 Biogeco, F- 33610, Cestas, France; UMR1202 Biogeco, Univ. Bordeaux, F-33400, Talence, France
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Slavov GT, DiFazio SP, Martin J, Schackwitz W, Muchero W, Rodgers-Melnick E, Lipphardt MF, Pennacchio CP, Hellsten U, Pennacchio LA, Gunter LE, Ranjan P, Vining K, Pomraning KR, Wilhelm LJ, Pellegrini M, Mockler TC, Freitag M, Geraldes A, El-Kassaby YA, Mansfield SD, Cronk QCB, Douglas CJ, Strauss SH, Rokhsar D, Tuskan GA. Genome resequencing reveals multiscale geographic structure and extensive linkage disequilibrium in the forest tree Populus trichocarpa. THE NEW PHYTOLOGIST 2012; 196:713-725. [PMID: 22861491 DOI: 10.1111/j.1469-8137.2012.04258.x] [Citation(s) in RCA: 118] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
• Plant population genomics informs evolutionary biology, breeding, conservation and bioenergy feedstock development. For example, the detection of reliable phenotype-genotype associations and molecular signatures of selection requires a detailed knowledge about genome-wide patterns of allele frequency variation, linkage disequilibrium and recombination. • We resequenced 16 genomes of the model tree Populus trichocarpa and genotyped 120 trees from 10 subpopulations using 29,213 single-nucleotide polymorphisms. • Significant geographic differentiation was present at multiple spatial scales, and range-wide latitudinal allele frequency gradients were strikingly common across the genome. The decay of linkage disequilibrium with physical distance was slower than expected from previous studies in Populus, with r(2) dropping below 0.2 within 3-6 kb. Consistent with this, estimates of recent effective population size from linkage disequilibrium (N(e) ≈ 4000-6000) were remarkably low relative to the large census sizes of P. trichocarpa stands. Fine-scale rates of recombination varied widely across the genome, but were largely predictable on the basis of DNA sequence and methylation features. • Our results suggest that genetic drift has played a significant role in the recent evolutionary history of P. trichocarpa. Most importantly, the extensive linkage disequilibrium detected suggests that genome-wide association studies and genomic selection in undomesticated populations may be more feasible in Populus than previously assumed.
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Affiliation(s)
- Gancho T Slavov
- Department of Biology, West Virginia University, Morgantown, WV 26506-6057, USA
- Institute of Biological, Environmental and Rural Sciences, Aberystwyth University, Aberystwyth, SY23 3EB, UK
| | - Stephen P DiFazio
- Department of Biology, West Virginia University, Morgantown, WV 26506-6057, USA
| | - Joel Martin
- US Department of Energy Joint Genome Institute, Walnut Creek, CA 94598, USA
| | - Wendy Schackwitz
- US Department of Energy Joint Genome Institute, Walnut Creek, CA 94598, USA
| | - Wellington Muchero
- BioSciences Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
| | - Eli Rodgers-Melnick
- Department of Biology, West Virginia University, Morgantown, WV 26506-6057, USA
| | - Mindie F Lipphardt
- Department of Biology, West Virginia University, Morgantown, WV 26506-6057, USA
| | | | - Uffe Hellsten
- US Department of Energy Joint Genome Institute, Walnut Creek, CA 94598, USA
| | - Len A Pennacchio
- US Department of Energy Joint Genome Institute, Walnut Creek, CA 94598, USA
| | - Lee E Gunter
- BioSciences Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
| | - Priya Ranjan
- BioSciences Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
| | - Kelly Vining
- Department of Forest Ecosystems and Society, Oregon State University, Corvallis, OR 97331-5752, USA
| | - Kyle R Pomraning
- Department of Biochemistry and Biophysics, Oregon State University, Corvallis, OR 97331-7305, USA
| | | | - Matteo Pellegrini
- Department of Molecular, Cell and Developmental Biology, University of California, Los Angeles, CA 90095-1606, USA
| | - Todd C Mockler
- Donald Danforth Plant Science Center, Saint Louis, MO 63132, USA
| | - Michael Freitag
- Department of Biochemistry and Biophysics, Oregon State University, Corvallis, OR 97331-7305, USA
| | - Armando Geraldes
- Department of Botany, University of British Columbia, Vancouver, BC, Canada, V6T 1Z4
| | - Yousry A El-Kassaby
- Department of Forest Sciences, University of British Columbia, Vancouver, BC, Canada, V6T 1Z4
| | - Shawn D Mansfield
- Department of Wood Science, University of British Columbia, Vancouver, BC, Canada, V6T 1Z4
| | - Quentin C B Cronk
- Department of Botany, University of British Columbia, Vancouver, BC, Canada, V6T 1Z4
| | - Carl J Douglas
- Department of Botany, University of British Columbia, Vancouver, BC, Canada, V6T 1Z4
| | - Steven H Strauss
- Department of Forest Ecosystems and Society, Oregon State University, Corvallis, OR 97331-5752, USA
| | - Dan Rokhsar
- US Department of Energy Joint Genome Institute, Walnut Creek, CA 94598, USA
| | - Gerald A Tuskan
- BioSciences Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
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Vanden-Broeck A, Cox K, Michiels B, Verschelde P, Villar M. With a little help from my friends: hybrid fertility of exotic Populus x canadensis enhanced by related native Populus nigra. Biol Invasions 2012. [DOI: 10.1007/s10530-012-0180-6] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/14/2022]
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