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Abstract
Convincing evidence has accumulated that unintended transgene escape occurs in oilseed rape, maize, cotton and creeping bentgrass. The escaped transgenes are found in variant cultivars, in wild type plants as well as in hybrids of sexually compatible species. The fact that in some cases stacked events are present that have not been planted commercially, implies unintended recombination of transgenic traits. As the consequences of this continuous transgene escape for the ecosystem cannot be reliably predicted, I propose to use more sophisticated approaches of gene technology in future. If possible GM plants should be constructed using either site-directed mutagenesis or cisgenic strategies to avoid the problem of transgene escape. In cases where a transgenic trait is needed, efficient containment should be the standard approach. Various strategies available or in development are discussed. Such a cautious approach in developing novel types of GM crops will enhance the sustainable potential of GM crops and thus increase the public trust in green gene technology.
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Affiliation(s)
- Gerhart U Ryffel
- a Institut für Zellbiologie (Tumorforschung); Universitätsklinikum Essen ; Essen , Germany
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52
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Liu Y, Stewart CN, Li J, Huang H, Zhang X. The presence of Bt-transgenic oilseed rape in wild mustard populations affects plant growth. Transgenic Res 2015; 24:1043-53. [PMID: 26338267 DOI: 10.1007/s11248-015-9903-7] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2015] [Accepted: 08/28/2015] [Indexed: 12/21/2022]
Abstract
The adventitious presence of transgenic plants in wild plant populations is of ecological and regulatory concern, but the consequences of adventitious presence are not well understood. Here, we introduced Bacillus thuringiensis Cry1Ac (Bt)-transgenic oilseed rape (Bt OSR, Brassica napus) with various frequencies into wild mustard (Brassica juncea) populations. We sought to better understand the adventitious presence of this transgenic insecticidal crop in a wild-relative plant population. We assessed the factors of competition, resource availability and diamondback moth (Plutella xylostella) infestation on plant population dynamics. As expected, Bt OSR performed better than wild mustard in mixed populations under herbivore attack in habitats with enough resources, whereas wild mustard had higher fitness when Bt OSR was rarer in habitats with limited resources. Results suggest that the presence of insect-resistant transgenic plants could decrease the growth of wild mustard and Bt OSR plants and their populations, especially under high herbivore pressure.
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Affiliation(s)
- Yongbo Liu
- State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, 8 Dayangfang, Beijing, 100012, China.
| | - C Neal Stewart
- Department of Plant Sciences, University of Tennessee, 2431 Joe Johnson Drive, Knoxville, TN, 37996-4561, USA
| | - Junsheng Li
- State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, 8 Dayangfang, Beijing, 100012, China
| | - Hai Huang
- State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, 8 Dayangfang, Beijing, 100012, China
| | - Xitao Zhang
- State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, 8 Dayangfang, Beijing, 100012, China
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54
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Cheung KW, Razeq FM, Sauder CA, James T, Martin SL. Bidirectional but asymmetrical sexual hybridization between Brassica carinata and Sinapis arvensis (Brassicaceae). JOURNAL OF PLANT RESEARCH 2015; 128:469-480. [PMID: 25698113 DOI: 10.1007/s10265-015-0702-2] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/24/2014] [Accepted: 12/01/2014] [Indexed: 06/04/2023]
Abstract
With transgenic crop development it is important to evaluate the potential for transgenes to escape into populations of wild, weedy relatives. Ethiopian mustard (Brassica carinata, BBCC) is easily transformed and is being investigated for uses from biodiesel fuels to biopharmaceuticals. However, little work has been done evaluating its ability to cross with relatives such as wild mustard (Sinapsis arvensis, SrSr), an abundant, cosmopolitan weedy relative. Here we conducted bidirectional crosses with Ethiopian mustard as a maternal parent in 997 crosses and paternal parent in 1,109 crosses. Hybrids were confirmed using flow cytometry and species-specific ITS molecular markers and indicate a high hybridization rate of 6.43 % between Ethiopian mustard (♀) and wild mustard (♂) and a lower, but not insignificant, hybridization rate of 0.01 % in the reverse direction. The majority of the hybrids were homoploid (BCSr) with less than 1 % of pollen production of their parents and low seed production (0.26 seeds/pollination) in crosses and backcrosses indicating a potential for advanced generation hybrids. The accession used had a significant effect on hybrid seed production with different accessions of Ethopian mustard varying in their production of hybrid offspring from 2.69 to 16.34 % and one accession of wild mustard siring almost twice as many hybrid offspring per flower as the other. One pentaploid (BBCCSr) and one hexaploid (BBCCSrSr) hybrid were produced and had higher pollen viability, though no and low seed production, respectively. As wild mustard is self-incompatible and the outcrossing rate of Ethiopian mustard has been estimated as 30 % potential for hybrid production in the wild appears to be high, though the hybridization rate found here represents a worst case scenario as it does not incorporate pre-pollination barriers. Hybridization in the wild needs to be directly evaluated as does the propensity of Ethiopian mustard to volunteer.
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Affiliation(s)
- Kyle W Cheung
- Eastern Cereal and Oilseed Research Centre, 960 Carling Ave., Ottawa, ON, K1A 0C6, Canada
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55
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Liu Y, Ge F, Liang Y, Wu G, Li J. Characterization of competitive interactions in the coexistence of Bt-transgenic and conventional rice. BMC Biotechnol 2015; 15:27. [PMID: 25928331 PMCID: PMC4409737 DOI: 10.1186/s12896-015-0141-0] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2014] [Accepted: 04/13/2015] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Transgene flow through pollen and seeds leads to transgenic volunteers and feral populations in the nature, and consumer choice and economic incentives determine whether transgenic crops will be cultivated in the field. Transgenic and non-transgenic plants are likely to coexist in the field and natural habitats, but their competitive interactions are not well understood. METHODS Field experiments were conducted in an agricultural ecosystem with insecticide spraying and a natural ecosystem, using Bt-transgenic rice (Oryza sativa) and its non-transgenic counterpart in pure and mixed stands with a replacement series. RESULTS Insect damage and competition significantly decreased plant growth and reproduction under the coexistence of transgenic and conventional rice. Insect-resistant transgenic rice was not competitively superior to its counterpart under different densities in both agricultural and natural ecosystems, irrespective of insect infection. Fitness cost due to Bt-transgene expression occurred only in an agroecosystem, where the population yield decreased with increasing percentage of transgenic rice. The population yield fluctuated in a natural ecosystem, with slight differences among pure and mixed stands under plant competition or insect pressure. The presence of Chilo suppressalis infection increased the number of non-target insects. CONCLUSIONS Plant growth and reproduction patterns, relative competition ability and population yield indicate that Bt-transgenic and non-transgenic rice can coexist in agroecosystems, whereas in more natural habitats, transgenic rice is likely to outcompete non-transgenic rice.
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Affiliation(s)
- Yongbo Liu
- State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing, 100012, China.
| | - Feng Ge
- State Key Laboratory of Integrated Management of Pest and Rodents, Institute of Zoology, the Chinese Academy of Sciences, 8 Dayangfang, Beijing, 100101, China.
| | - Yuyong Liang
- Institute of Plant Protection, Jiangxi Academy of Agricultural Sciences, Nanchang, 330200, China.
| | - Gang Wu
- Hubei Insect Resources Utilization and Sustainable Pest Management Key Laboratory, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, 430070, China.
| | - Junsheng Li
- State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing, 100012, China.
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56
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Glaum P, Vandermeer J. Potential for and consequences of naturalized Bt products: Qualitative dynamics from indirect intransitivities. Ecol Modell 2015. [DOI: 10.1016/j.ecolmodel.2014.12.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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57
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Pace BA, Alexander HM, Emry JD, Mercer KL. Seed fates in crop-wild hybrid sunflower: crop allele and maternal effects. Evol Appl 2015; 8:121-32. [PMID: 25685189 PMCID: PMC4319861 DOI: 10.1111/eva.12236] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2014] [Accepted: 10/07/2014] [Indexed: 11/28/2022] Open
Abstract
Domestication has resulted in selection upon seed traits found in wild populations, yet crop-wild hybrids retain some aspects of both parental phenotypes. Seed fates of germination, dormancy, and mortality can influence the success of crop allele introgression in crop-wild hybrid zones, especially if crop alleles or crop-imparted seed coverings result in out-of-season germination. We performed a seed burial experiment using crop, wild, and diverse hybrid sunflower (Helianthus annuus) cross types to test how a cross type's maternal parent and nuclear genetic composition might affect its fate under field conditions. We observed higher maladaptive fall germination in the crop- and F1- produced seeds than wild-produced seeds and, due to an interaction with percent crop alleles, fall germination was higher for cross types with more crop-like nuclear genetics. By spring, crop-produced cross types had the highest overwintering mortality, primarily due to higher fall germination. Early spring germination was identical across maternal types, but germination continued for F1-produced seeds. In conclusion, the more wild-like the maternal parent or the less proportion of the cross type's genome contributed by the crop, the greater likelihood a seed will remain ungerminated than die. Wild-like dormancy may facilitate introgression through future recruitment from the soil seed bank.
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Affiliation(s)
- Brian A Pace
- Department of Horticulture and Crop Science, Ohio State University Columbus, OH, USA
| | - Helen M Alexander
- Department of Ecology and Evolutionary Biology, University of Kansas Lawrence, KS, USA
| | - Jason D Emry
- Department of Biology, Washburn University Topeka, KS, USA
| | - Kristin L Mercer
- Department of Horticulture and Crop Science, Ohio State University Columbus, OH, USA
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58
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Roumet M, Cayre A, Latreille M, Muller MH. Quantifying temporal isolation: a modelling approach assessing the effect of flowering time differences on crop-to-weed pollen flow in sunflower. Evol Appl 2015; 8:64-74. [PMID: 25667603 PMCID: PMC4310582 DOI: 10.1111/eva.12222] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2014] [Accepted: 09/15/2014] [Indexed: 01/08/2023] Open
Abstract
Flowering time divergence can be a crucial component of reproductive isolation between sympatric populations, but few studies have quantified its actual contribution to the reduction of gene flow. In this study, we aimed at estimating pollen-mediated gene flow between cultivated sunflower and a weedy conspecific sunflower population growing in the same field and at quantifying, how it is affected by the weeds' flowering time. For that purpose, we extended an existing mating model by including a temporal distance (i.e. flowering time difference between potential parents) effect on mating probabilities. Using phenological and genotypic data gathered on the crop and on a sample of the weedy population and its offspring, we estimated an average hybridization rate of approximately 10%. This rate varied strongly from 30% on average for weeds flowering at the crop flowering peak to 0% when the crop finished flowering and was affected by the local density of weeds. Our result also suggested the occurrence of other factors limiting crop-to-weed gene flow. This level of gene flow and its dependence on flowering time might influence the evolutionary fate of weedy sunflower populations sympatric to their crop relative.
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Affiliation(s)
- Marie Roumet
- INRA, UMR 1334, Amélioration Génétique et Adaptation des Plantes méditerranéennes et tropicales (AGAP) Montpellier Cedex 1, France ; ETH Zurich, Institute of Integrative Biology (IBZ) Zurich, Switzerland
| | - Adeline Cayre
- INRA, UMR 1334, Amélioration Génétique et Adaptation des Plantes méditerranéennes et tropicales (AGAP) Montpellier Cedex 1, France
| | - Muriel Latreille
- INRA, UMR 1334, Amélioration Génétique et Adaptation des Plantes méditerranéennes et tropicales (AGAP) Montpellier Cedex 1, France
| | - Marie-Hélène Muller
- INRA, UMR 1334, Amélioration Génétique et Adaptation des Plantes méditerranéennes et tropicales (AGAP) Montpellier Cedex 1, France
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Davidar P, Snow AA, Rajkumar M, Pasquet R, Daunay MC, Mutegi E. The potential for crop to wild hybridization in eggplant (Solanum melongena; Solanaceae) in southern India. AMERICAN JOURNAL OF BOTANY 2015; 102:129-39. [PMID: 25587155 DOI: 10.3732/ajb.1400404] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
UNLABELLED • PREMISE OF THE STUDY In India and elsewhere, transgenic Bt eggplant (Solanum melongena) has been developed to reduce insect herbivore damage, but published studies of the potential for pollen-mediated, crop- to- wild gene flow are scant. This information is useful for risk assessments as well as in situ conservation strategies for wild germplasm.• METHODS In 2010-2014, we surveyed 23 populations of wild/weedy eggplant (Solanum insanum; known as wild brinjal), carried out hand-pollination experiments, and observed pollinators to assess the potential for crop- to- wild gene flow in southern India.• KEY RESULTS Wild brinjal is a spiny, low-growing perennial commonly found in disturbed sites such as roadsides, wastelands, and sparsely vegetated areas near villages and agricultural fields. Fourteen of the 23 wild populations in our study occurred within 0.5 km of cultivated brinjal and at least nine flowered in synchrony with the crop. Hand crosses between wild and cultivated brinjal resulted in seed set and viable F1 progeny. Wild brinjal flowers that were bagged to exclude pollinators did not set fruit, and fruit set from manual self-pollination was low. The exserted stigmas of wild brinjal are likely to promote outcrossing. The most effective pollinators appeared to be bees (Amegilla, Xylocopa, Nomia, and Heterotrigona spp.), which also were observed foraging for pollen on crop brinjal.• CONCLUSION Our findings suggest that hybridization is possible between cultivated and wild brinjal in southern India. Thus, as part of the risk assessment process, we assume that transgenes from the crop could spread to wild brinjal populations that occur nearby.
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Affiliation(s)
- Priya Davidar
- Department of Ecology and Environmental Sciences, Pondicherry University, Kalapet, Pondicherry 605014, India
| | - Allison A Snow
- Department of Evolution, Ecology, and Organismal Biology, Ohio State University, 318 W. 12th Avenue, Columbus, Ohio 43210 USA
| | - Muthu Rajkumar
- Department of Ecology and Environmental Sciences, Pondicherry University, Kalapet, Pondicherry 605014, India
| | - Remy Pasquet
- IRD, UR 072, LEGS 91198 Gif-sur-yvette, France; Université Paris-Sud 11 91400 Orsay, France
| | - Marie-Christine Daunay
- INRA, Unité de Génétique & Amélioration des Fruits et Légumes, UR1052, Domaine St Maurice, CS 60094 F-84143 Montfavet cedex, France
| | - Evans Mutegi
- Department of Evolution, Ecology, and Organismal Biology, Ohio State University, 318 W. 12th Avenue, Columbus, Ohio 43210 USA
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Rapson S, Wu M, Okada S, Das A, Shrestha P, Zhou XR, Wood C, Green A, Singh S, Liu Q. A case study on the genetic origin of the high oleic acid trait through FAD2-1 DNA sequence variation in safflower (Carthamus tinctorius L.). FRONTIERS IN PLANT SCIENCE 2015; 6:691. [PMID: 26442008 PMCID: PMC4563165 DOI: 10.3389/fpls.2015.00691] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/15/2015] [Accepted: 08/21/2015] [Indexed: 05/15/2023]
Abstract
The safflower (Carthamus tinctorius L.) is considered a strongly domesticated species with a long history of cultivation. The hybridization of safflower with its wild relatives has played an important role in the evolution of cultivars and is of particular interest with regards to their production of high quality edible oils. Original safflower varieties were all rich in linoleic acid, while varieties rich in oleic acid have risen to prominence in recent decades. The high oleic acid trait is controlled by a partially recessive allele ol at a single locus OL. The ol allele was found to be a defective microsomal oleate desaturase FAD2-1. Here we present DNA sequence data and Southern blot analysis suggesting that there has been an ancient hybridization and introgression of the FAD2-1 gene into C. tinctorius from its wild relative C. palaestinus. It is from this gene that FAD2-1Δ was derived more recently. Identification and characterization of the genetic origin and diversity of FAD2-1 could aid safflower breeders in reducing population size and generations required for the development of new high oleic acid varieties by using perfect molecular marker-assisted selection.
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Affiliation(s)
- Sara Rapson
- Commonwealth Scientific and Industrial Research Organization AgricultureCanberra, ACT, Australia
| | - Man Wu
- Commonwealth Scientific and Industrial Research Organization AgricultureCanberra, ACT, Australia
- State Key Laboratory of Cotton Biology, Institute of Cotton Research of Chinese Academy of Agricultural SciencesAnyang, China
| | - Shoko Okada
- Commonwealth Scientific and Industrial Research Organization Land and WaterCanberra, ACT, Australia
| | - Alpana Das
- Commonwealth Scientific and Industrial Research Organization AgricultureCanberra, ACT, Australia
- Indian Council of Agricultural Research, Central Plantation Crops Research InstituteRC, Assam, India
| | - Pushkar Shrestha
- Commonwealth Scientific and Industrial Research Organization AgricultureCanberra, ACT, Australia
| | - Xue-Rong Zhou
- Commonwealth Scientific and Industrial Research Organization AgricultureCanberra, ACT, Australia
| | - Craig Wood
- Commonwealth Scientific and Industrial Research Organization AgricultureCanberra, ACT, Australia
| | - Allan Green
- Commonwealth Scientific and Industrial Research Organization Food and NutritionCanberra, ACT, Australia
| | - Surinder Singh
- Commonwealth Scientific and Industrial Research Organization AgricultureCanberra, ACT, Australia
| | - Qing Liu
- Commonwealth Scientific and Industrial Research Organization AgricultureCanberra, ACT, Australia
- *Correspondence: Qing Liu, Commonwealth Scientific and Industrial Research Organization Agriculture, PO Box 1600, Canberra, ACT 2601, Australia
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61
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Liu YB, Darmency H, Stewart CN, Wei W, Tang ZX, Ma KP. The effect of Bt-transgene introgression on plant growth and reproduction in wild Brassica juncea. Transgenic Res 2014; 24:537-47. [PMID: 25487040 DOI: 10.1007/s11248-014-9858-0] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2014] [Accepted: 12/02/2014] [Indexed: 10/24/2022]
Abstract
This study aims to investigate the relative plant growth and reproduction of insect-resistant and susceptible plants following the introgression of an insect-resistance Bt-transgene from Brassica napus, oilseed rape, to wild Brassica juncea. The second backcrossed generation (BC2) from a single backcross family was grown in pure and mixed stands of Bt-transgenic and non-transgenic siblings under two insect treatments. Various proportions of Bt-transgenic plants were employed in mixed stands to study the interaction between resistant and susceptible plants. In the pure stands, Bt-transgenic BC2 plants performed better than non-transgenic plants with or without insect treatments. In mixed stands, Bt-transgenic BC2 plants produced fewer seeds than their non-Bt counterparts at low proportions of Bt-transgenic BC2 plants in the absence of insects. Reproductive allocation of non-transgenic plants marginally increased with increasing proportions of Bt-transgenic plants under herbivore pressure, which resulted in increased total biomass and seed production per stand. The results showed that the growth of non-transgenic plants was protected by Bt-transgenic plants under herbivore pressure. The Bt-transgene might not be advantageous in mixed stands of backcrossed hybrids; thus transgene introgression would not be facilitated when herbivorous insects are not present. However, a relatively large initial population of Bt-transgenic plants might result in transgene persistence when target herbivores are present.
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Affiliation(s)
- Yong-Bo Liu
- State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Sciences, 20 Nanxincun, Beijing, 100093, China
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Schulze J, Frauenknecht T, Brodmann P, Bagutti C. Unexpected diversity of feral genetically modified oilseed rape (Brassica napus L.) despite a cultivation and import ban in Switzerland. PLoS One 2014; 9:e114477. [PMID: 25464509 PMCID: PMC4252112 DOI: 10.1371/journal.pone.0114477] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2014] [Accepted: 11/10/2014] [Indexed: 11/18/2022] Open
Abstract
Despite cultivation and seed import bans of genetically modified (GM) oilseed rape (Brassica napus L.), feral GM plants were found growing along railway lines and in port areas at four sites in Switzerland in 2011 and 2012. All GM plants were identified as glyphosate-resistant GM event GT73 (Roundup Ready, Monsanto). The most affected sites were the Rhine port of Basel and the St. Johann freight railway station in Basel. To assess the distribution and intra- and interspecific outcrossing of GM oilseed rape in more detail, we monitored these two sites in 2013. Leaves and seed pods of feral oilseed rape plants, their possible hybridization partners and putative hybrid plants were sampled in monthly intervals and analysed for the presence of transgenes by real-time PCR. Using flow cytometry, we measured DNA contents of cell nuclei to confirm putative hybrids. In total, 2787 plants were sampled. The presence of GT73 oilseed rape could be confirmed at all previously documented sampling locations and was additionally detected at one new sampling location within the Rhine port. Furthermore, we found the glufosinate-resistant GM events MS8xRF3, MS8 and RF3 (all traded as InVigor, Bayer) at five sampling locations in the Rhine port. To our knowledge, this is the first time that feral MS8xRF3, MS8 or RF3 plants were detected in Europe. Real-time PCR analyses of seeds showed outcrossing of GT73 into two non-GM oilseed rape plants, but no outcrossing of transgenes into related wild species was observed. We found no hybrids between oilseed rape and related species. GM plants most frequently occurred at unloading sites for ships, indicating that ship cargo traffic is the main entry pathway for GM oilseed rape. In the future, it will be of major interest to determine the source of GM oilseed rape seeds.
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Affiliation(s)
- Juerg Schulze
- State Laboratory Basel-City, Biosafety Laboratory, Basel, Switzerland
| | - Tina Frauenknecht
- State Laboratory Basel-City, Biosafety Laboratory, Basel, Switzerland
| | - Peter Brodmann
- State Laboratory Basel-City, Biosafety Laboratory, Basel, Switzerland
| | - Claudia Bagutti
- State Laboratory Basel-City, Biosafety Laboratory, Basel, Switzerland
- * E-mail:
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Pajkovic M, Lappe S, Barman R, Parisod C, Neuenschwander S, Goudet J, Alvarez N, Guadagnuolo R, Felber F, Arrigo N. Wheat alleles introgress into selfing wild relatives: empirical estimates from approximate Bayesian computation inAegilops triuncialis. Mol Ecol 2014; 23:5089-101. [DOI: 10.1111/mec.12918] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2014] [Revised: 09/03/2014] [Accepted: 09/10/2014] [Indexed: 11/26/2022]
Affiliation(s)
- Mila Pajkovic
- Department of Ecology and Evolution; University of Lausanne; Lausanne CH-1015 Switzerland
| | - Sylvain Lappe
- Laboratory of Evolutionary Botany; Institute of Biology; University of Neuchatel; Emile-Argand 11 Neuchatel CH-2001 Switzerland
| | - Rachel Barman
- Department of Ecology and Evolution; University of Lausanne; Lausanne CH-1015 Switzerland
| | - Christian Parisod
- Laboratory of Evolutionary Botany; Institute of Biology; University of Neuchatel; Emile-Argand 11 Neuchatel CH-2001 Switzerland
| | - Samuel Neuenschwander
- Department of Ecology and Evolution; University of Lausanne; Lausanne CH-1015 Switzerland
- Vital-IT; Swiss Institute of Bioinformatics; University of Lausanne; Lausanne Switzerland
| | - Jerome Goudet
- Department of Ecology and Evolution; University of Lausanne; Lausanne CH-1015 Switzerland
- Vital-IT; Swiss Institute of Bioinformatics; University of Lausanne; Lausanne Switzerland
| | - Nadir Alvarez
- Department of Ecology and Evolution; University of Lausanne; Lausanne CH-1015 Switzerland
| | - Roberto Guadagnuolo
- Laboratory of Evolutionary Botany; Institute of Biology; University of Neuchatel; Emile-Argand 11 Neuchatel CH-2001 Switzerland
| | - François Felber
- Musée et Jardins botaniques cantonaux vaudois; Lausanne CH-1007 Switzerland
| | - Nils Arrigo
- Department of Ecology and Evolution; University of Lausanne; Lausanne CH-1015 Switzerland
- Laboratory of Evolutionary Botany; Institute of Biology; University of Neuchatel; Emile-Argand 11 Neuchatel CH-2001 Switzerland
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Cao D, Stewart CN, Zheng M, Guan Z, Tang ZX, Wei W, Ma KP. Stable Bacillus thuringiensis transgene introgression from Brassica napus to wild mustard B. juncea. PLANT SCIENCE : AN INTERNATIONAL JOURNAL OF EXPERIMENTAL PLANT BIOLOGY 2014; 227:45-50. [PMID: 25219305 DOI: 10.1016/j.plantsci.2014.06.018] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/29/2014] [Revised: 06/27/2014] [Accepted: 06/28/2014] [Indexed: 06/03/2023]
Abstract
Transgenic canola (Brassica napus) with a Bacillus thuringiensis cry1Ac gene and a green fluorescent protein (GFP) marker gene was used in hybridization experiments with wild Brassica juncea. Hybrid F1 and successive five backcross generations were obtained. The pod-set frequency on backcrossed B. juncea plants was over 66%, which suggested relatively high crossing compatibility between the hybrids and wild species. The seed setting in BC1 was the least of all generations tested, and then increased at the BC2 generation for which the thousand-seed weight was the highest of all generations. Seed size in backcrossed generations eventually approached that of the wild parent. The plants in all backcrossed generations were consistent with the expected 1:1 segregation ratio of the transgenes. The Bt Cry1Ac protein concentrations at bolting and flowering stages was higher compared to the 4-5-leaf and pod-formation stages. Nonetheless, the Bt toxin in the fifth backcrossing generation (BC5) was sufficient to kill both polyphagous (Helicoverpa armigera) and oligophagous (Plutella xylostella) Lepidoptera. As a consequence, the subsequent generations harboring the transgene from F1 to BC5 could have selection advantage against insect pests. The result is useful in understanding gene flow from transgenic crops and the followed transgene introgression into wild.
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Affiliation(s)
- Di Cao
- State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Sciences, 20 Nanxincun, Beijing 100093, China
| | - C Neal Stewart
- Department of Plant Sciences, University of Tennessee, 2431 Joe Johnson Drive, Knoxville, TN 37996-4561, USA
| | - Min Zheng
- State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Sciences, 20 Nanxincun, Beijing 100093, China
| | - Zhengjun Guan
- State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Sciences, 20 Nanxincun, Beijing 100093, China
| | - Zhi-Xi Tang
- State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Sciences, 20 Nanxincun, Beijing 100093, China
| | - Wei Wei
- State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Sciences, 20 Nanxincun, Beijing 100093, China.
| | - Ke-Ping Ma
- State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Sciences, 20 Nanxincun, Beijing 100093, China
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Bagavathiannan MV, Norsworthy JK. Pollen-mediated transfer of herbicide resistance in Echinochloa crus-galli. PEST MANAGEMENT SCIENCE 2014; 70:1425-1431. [PMID: 24623467 DOI: 10.1002/ps.3775] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/07/2013] [Revised: 12/23/2013] [Indexed: 06/03/2023]
Abstract
BACKGROUND Pollen-mediated gene flow (PMGF) can facilitate the dispersal and spread of herbicide resistance from one weed population to another within an agricultural landscape. The aim of this study was to quantify the extent of PMGF in Echinochloa crus-galli (barnyardgrass), an important herbicide-resistant weed species in the United States and across the world. RESULTS Gene flow declined exponentially with distance, and the double exponential decay model predicted an average gene flow of 5.6% when the pollen donor and recipient plants were at a close distance of 0.25 m from each other (12.5% at 0 m). Gene flow declined by 90% at 0.9 m from the pollen source, yet gene flow was detected as far as 50 m (the farthest distance studied). The farthest gene flow occurred in directions of the fastest wind events, but mean gene flow levels were similar among the directions. CONCLUSION Results indicate that long-distance, landscape-scale PMGF is unlikely in barnyardgrass, but gene flow is likely to occur between adjacent fields at levels greater than initial frequencies of resistance alleles in natural, unselected populations. Thus, any resistance management strategy should consider the likelihood that PMGF can contribute to the spread of herbicide resistance between production fields.
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66
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Uecker H, Setter D, Hermisson J. Adaptive gene introgression after secondary contact. J Math Biol 2014; 70:1523-80. [PMID: 24992884 PMCID: PMC4426140 DOI: 10.1007/s00285-014-0802-y] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2013] [Revised: 05/21/2014] [Indexed: 11/09/2022]
Abstract
By hybridization and backcrossing, alleles can surmount species boundaries and be incorporated into the genome of a related species. This introgression of genes is of particular evolutionary relevance if it involves the transfer of adaptations between populations. However, any beneficial allele will typically be associated with other alien alleles that are often deleterious and hamper the introgression process. In order to describe the introgression of an adaptive allele, we set up a stochastic model with an explicit genetic makeup of linked and unlinked deleterious alleles. Based on the theory of reducible multitype branching processes, we derive a recursive expression for the establishment probability of the beneficial allele after a single hybridization event. We furthermore study the probability that slightly deleterious alleles hitchhike to fixation. The key to the analysis is a split of the process into a stochastic phase in which the advantageous alleles establishes and a deterministic phase in which it sweeps to fixation. We thereafter apply the theory to a set of biologically relevant scenarios such as introgression in the presence of many unlinked or few closely linked deleterious alleles. A comparison to computer simulations shows that the approximations work well over a large parameter range.
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Affiliation(s)
- Hildegard Uecker
- Mathematics and Biosciences Group, Faculty of Mathematics and Max F. Perutz Laboratories, University of Vienna, 1090 , Vienna, Austria,
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67
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Goldstein DA. Tempest in a tea pot: How did the public conversation on genetically modified crops drift so far from the facts? J Med Toxicol 2014; 10:194-201. [PMID: 24798648 PMCID: PMC4057531 DOI: 10.1007/s13181-014-0402-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/04/2022] Open
Abstract
The debate over genetically modified (GM) crops has raged in Europe since 1996, but had barely risen above a whisper in the USA until recent labeling debates raised public attention. This article will explain GM crops and traits discuss safety assessment provide a view on safety from authoritative organizations discuss selected issues of current debate, and provide the author's perspective as to why the public debate has drifted so far from scientific reality. The economic and environmental benefits of GM crops are beyond scope, but references are provided. GM food and feed undergo comprehensive assessments using recognized approaches to assure they are as safe as the conventional congener. Issues of food safety and nutrition, unrelated to the GM process, may arise when GM foods display novel components or composition. Unanticipated genetic effects in GM crops appear to be limited in contrast to existing variations among conventional varieties resulting from breeding, mutation, and natural mobile genetic elements. Allergenic potential is assessed when selecting genes for introduction into GM crops and remains a theoretical risk to date. Emerging weed and insect resistance is not unique to GM technology and will require the use of integrated pest management/best practices for pest control. Gene flow from GM crops to wild relatives is limited by existing biological barriers but can at time be a relevant consideration in gene selection and planting practices. Insect-resistant GM crops have significantly reduced use of chemical insecticides and appear to have reduced the incidence of pesticide poisoning in areas where small scale farming and hand application are common. Changes in herbicide patterns are more complex and are evolving over time in response to weed resistance management needs. Recent public debate is driven by a combination of unfounded allegations about the technology and purveyors, pseudoscience, and attempts to apply a strict precautionary principle.
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Affiliation(s)
- Daniel A Goldstein
- Regulatory Affairs, Monsanto Company, Monsanto, Mail Zone C3ND, 800 N.Blvd. St. Louis, Lindbergh, MO, 63167, USA,
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68
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Safont E, Rull V, Vegas-vilarrúbia T, Holst BK, Huber O, Nozawa S, Vivas Y, Silva A. Establishing a baseline of plant diversity and endemism on a neotropical mountain summit for future comparative studies assessing upward migration: an approach from biogeography and nature conservation. SYST BIODIVERS 2014. [DOI: 10.1080/14772000.2014.918061] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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69
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Hartman Y, Hooftman DAP, Uwimana B, Schranz ME, van de Wiel CCM, Smulders MJM, Visser RGF, Michelmore RW, van Tienderen PH. Abiotic stress QTL in lettuce crop-wild hybrids: comparing greenhouse and field experiments. Ecol Evol 2014; 4:2395-409. [PMID: 25360276 PMCID: PMC4203288 DOI: 10.1002/ece3.1060] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2013] [Revised: 03/03/2014] [Accepted: 03/11/2014] [Indexed: 11/11/2022] Open
Abstract
The development of stress-tolerant crops is an increasingly important goal of current crop breeding. A higher abiotic stress tolerance could increase the probability of introgression of genes from crops to wild relatives. This is particularly relevant to the discussion on the risks of new GM crops that may be engineered to increase abiotic stress resistance. We investigated abiotic stress QTL in greenhouse and field experiments in which we subjected recombinant inbred lines from a cross between cultivated Lactuca sativa cv. Salinas and its wild relative L. serriola to drought, low nutrients, salt stress, and aboveground competition. Aboveground biomass at the end of the rosette stage was used as a proxy for the performance of plants under a particular stress. We detected a mosaic of abiotic stress QTL over the entire genome with little overlap between QTL from different stresses. The two QTL clusters that were identified reflected general growth rather than specific stress responses and colocated with clusters found in earlier studies for leaf shape and flowering time. Genetic correlations across treatments were often higher among different stress treatments within the same experiment (greenhouse or field), than among the same type of stress applied in different experiments. Moreover, the effects of the field stress treatments were more correlated with those of the greenhouse competition treatments than to those of the other greenhouse stress experiments, suggesting that competition rather than abiotic stress is a major factor in the field. In conclusion, the introgression risk of stress tolerance (trans-)genes under field conditions cannot easily be predicted based on genomic background selection patterns from controlled QTL experiments in greenhouses, especially field data will be needed to assess potential (negative) ecological effects of introgression of these transgenes into wild relatives.
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Affiliation(s)
- Yorike Hartman
- Institute for Biodiversity and Ecosystem Dynamics, Universiteit van Amsterdam Amsterdam, The Netherlands
| | - Danny A P Hooftman
- Institute for Biodiversity and Ecosystem Dynamics, Universiteit van Amsterdam Amsterdam, The Netherlands ; NERC, Centre for Ecology and Hydrology Wallingford, UK
| | - Brigitte Uwimana
- Wageningen UR Plant Breeding, Wageningen University and Research Centre Wageningen, The Netherlands
| | - M Eric Schranz
- Institute for Biodiversity and Ecosystem Dynamics, Universiteit van Amsterdam Amsterdam, The Netherlands
| | - Clemens C M van de Wiel
- Wageningen UR Plant Breeding, Wageningen University and Research Centre Wageningen, The Netherlands
| | - Marinus J M Smulders
- Wageningen UR Plant Breeding, Wageningen University and Research Centre Wageningen, The Netherlands
| | - Richard G F Visser
- Wageningen UR Plant Breeding, Wageningen University and Research Centre Wageningen, The Netherlands
| | - Richard W Michelmore
- Genome Center and Department of Plant Sciences, University of California Davis, California
| | - Peter H van Tienderen
- Institute for Biodiversity and Ecosystem Dynamics, Universiteit van Amsterdam Amsterdam, The Netherlands
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70
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Ellstrand NC. Is gene flow the most important evolutionary force in plants? AMERICAN JOURNAL OF BOTANY 2014; 101:737-53. [PMID: 24752890 DOI: 10.3732/ajb.1400024] [Citation(s) in RCA: 128] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/18/2014] [Accepted: 03/17/2014] [Indexed: 05/02/2023]
Abstract
Although theory has demonstrated rather low levels of gene flow are sufficient to counteract opposing mutation, drift, and selection, widespread recognition of the evolutionary importance of gene flow has come slowly. The perceived role of gene flow as an evolutionary force has vacillated over the last century. In the last few decades, new methods and analyses have demonstrated that plant gene flow rates vary tremendously-from nil to very high-depending on the species and specific populations involved, and sometimes over time for individual populations. In many cases, the measured gene flow rates are evolutionarily significant at distances of hundreds and sometimes thousands of meters, occurring at levels sufficient to counteract drift, spread advantageous alleles, or thwart moderate levels of opposing local selection. Gene flow in plants is likely to often act as a cohesive force, uniting individual plant species into real evolutionary units. Also, gene flow can evolve under natural selection, decreasing or increasing. The fact of frequent, but variable, plant gene flow has important consequences for applied issues in which the presence or absence of gene flow might influence the outcome of a policy, regulatory, or management decision. Examples include the unintended spread of engineered genes, the evolution of invasiveness, and conservation. New data-rich genomic techniques allow closer scrutiny of the role of gene flow in plant evolution. Most plant evolutionists now recognize the importance of gene flow, and it is receiving increased recognition from other areas of plant biology as well.
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Affiliation(s)
- Norman C Ellstrand
- Department of Botany and Plant Sciences, University of California, Riverside, California 92521-0124 USA
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71
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A stochastic cellular model with uncertainty analysis to assess the risk of transgene invasion after crop-wild hybridization: Oilseed rape and wild radish as a case study. Ecol Modell 2014. [DOI: 10.1016/j.ecolmodel.2014.01.004] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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72
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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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73
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Protection goals in environmental risk assessment: a practical approach. Transgenic Res 2013; 23:945-56. [DOI: 10.1007/s11248-013-9760-1] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2013] [Accepted: 10/06/2013] [Indexed: 10/26/2022]
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74
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Spatial and temporal assessment of pollen- and seed-mediated gene flow from genetically engineered plum Prunus domestica. PLoS One 2013; 8:e75291. [PMID: 24098374 PMCID: PMC3788040 DOI: 10.1371/journal.pone.0075291] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2013] [Accepted: 08/12/2013] [Indexed: 11/19/2022] Open
Abstract
Pollen flow from a 0.46 ha plot of genetically engineered (GE) Prunus domestica located in West Virginia, USA was evaluated from 2000-2010. Sentinel plum trees were planted at distances ranging from 132 to 854 m from the center of the GE orchard. Plots of mixed plum varieties and seedlings were located at 384, 484 and 998 m from the GE plot. Bee hives (Apis mellifera) were dispersed between the GE plum plot and the pollen flow monitoring sites. Pollen-mediated gene flow from out of the GE plum plot to non-GE plums under the study conditions was low, only occurring at all in 4 of 11 years and then in only 0.31% of the 12,116 seeds analyzed. When it occurred, gene flow, calculated as the number of GUS positive embryos/total embryos sampled, ranged from 0.215% at 132 m from the center of the GE plum plot (28 m from the nearest GE plum tree) to 0.033-0.017% at longer distances (384-998 m). Based on the percentage of GUS positive seeds per individual sampled tree the range was 0.4% to 12%. Within the GE field plot, gene flow ranged from 4.9 to 39%. Gene flow was related to distance and environmental conditions. A single year sample from a sentinel plot 132 m from the center of the GE plot accounted for 65% of the total 11-year gene flow. Spatial modeling indicated that gene flow dramatically decreased at distances over 400 m from the GE plot. Air temperature and rainfall were, respectively, positively and negatively correlated with gene flow, reflecting the effects of weather conditions on insect pollinator activity. Seed-mediated gene flow was not detected. These results support the feasibility of coexistence of GE and non-GE plum orchards.
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75
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Sang Y, Millwood RJ, Neal Stewart C. Gene use restriction technologies for transgenic plant bioconfinement. PLANT BIOTECHNOLOGY JOURNAL 2013; 11:649-658. [PMID: 23730743 DOI: 10.1111/pbi.12084] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/01/2013] [Revised: 04/03/2013] [Accepted: 04/09/2013] [Indexed: 06/02/2023]
Abstract
The advances of modern plant technologies, especially genetically modified crops, are considered to be a substantial benefit to agriculture and society. However, so-called transgene escape remains and is of environmental and regulatory concern. Genetic use restriction technologies (GURTs) provide a possible solution to prevent transgene dispersal. Although GURTs were originally developed as a way for intellectual property protection (IPP), we believe their maximum benefit could be in the prevention of gene flow, that is, bioconfinement. This review describes the underlying signal transduction and components necessary to implement any GURT system. Furthermore, we review the similarities and differences between IPP- and bioconfinement-oriented GURTs, discuss the GURTs' design for impeding transgene escape and summarize recent advances. Lastly, we go beyond the state of the science to speculate on regulatory and ecological effects of implementing GURTs for bioconfinement.
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Affiliation(s)
- Yi Sang
- Department of Plant Sciences, University of Tennessee, Knoxville, TN, USA
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76
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Kuroda Y, Kaga A, Tomooka N, Yano H, Takada Y, Kato S, Vaughan D. QTL affecting fitness of hybrids between wild and cultivated soybeans in experimental fields. Ecol Evol 2013; 3:2150-68. [PMID: 23919159 PMCID: PMC3728954 DOI: 10.1002/ece3.606] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2013] [Revised: 04/24/2013] [Accepted: 04/25/2013] [Indexed: 11/30/2022] Open
Abstract
The objective of this study was to identify quantitative trait loci (QTL) affecting fitness of hybrids between wild soybean (Glycine soja) and cultivated soybean (Glycine max). Seed dormancy and seed number, both of which are important for fitness, were evaluated by testing artificial hybrids of G. soja × G. max in a multiple-site field trial. Generally, the fitness of the F1 hybrids and hybrid derivatives from self-pollination was lower than that of G. soja due to loss of seed dormancy, whereas the fitness of hybrid derivatives with higher proportions of G. soja genetic background was comparable with that of G. soja. These differences were genetically dissected into QTL for each population. Three QTLs for seed dormancy and one QTL for total seed number were detected in the F2 progenies of two diverse cross combinations. At those four QTLs, the G. max alleles reduced seed number and severely reduced seed survival during the winter, suggesting that major genes acquired during soybean adaptation to cultivation have a selective disadvantage in natural habitats. In progenies with a higher proportion of G. soja genetic background, the genetic effects of the G. max alleles were not expressed as phenotypes because the G. soja alleles were dominant over the G. max alleles. Considering the highly inbreeding nature of these species, most hybrid derivatives would disappear quickly in early self-pollinating generations in natural habitats because of the low fitness of plants carrying G. max alleles.
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Affiliation(s)
- Yosuke Kuroda
- National Institute of Agrobiological Sciences 2-1-2 Kannondai, Tsukuba, Ibaraki, 305-8602, Japan
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77
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Grebenstein C, Kos SP, de Jong TJ, Tamis WLM, de Snoo GR. Morphological markers for the detection of introgression from cultivated into wild carrot (Daucus carota L.) reveal dominant domestication traits. PLANT BIOLOGY (STUTTGART, GERMANY) 2013; 15:531-540. [PMID: 23173917 DOI: 10.1111/j.1438-8677.2012.00662.x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
Hybridisation and subsequent introgression have recently received much attention in the context of genetically modified crops. But crop-wild hybrid detection in the field can be difficult, as most domestication traits seem to be recessive, and the hybrid phenotype may also depend on the direction of the cross or environmental factors. Our aim was to develop a reliable set of morphological markers that differ between two wild and 13 cultivated carrots (Daucus carota L.) and to evaluate their inheritance in hybrid lines. We then examined these morphological markers in four F1 hybrids obtained by fertilising plants from the two wild accessions with pollen from two common carrot cultivars. Of the 16 traits that differed between the two carrot subspecies, three took intermediate values in the hybrids, eight resembled the cultivar parent (dominant domestication traits), two resembled the wild parent (domestication traits recessive), and three were not significant or growth condition-dependent. Root:shoot ratio was seven times higher for cultivars than for wild plants, while still attaining equivalent total dry weight, which shows that dry matter production by the shoot is much higher in cultivars than in wild plants. High root:shoot ratios were also present in the hybrids. While we found no maternal effects, the type of cultivar used for pollination had an impact on hybrid characteristics. The morphological markers developed here provide insights into the mode of inheritance of ecologically relevant traits and can be useful for pre-screening wild populations for hybrid detection prior to genetic analysis.
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Affiliation(s)
- C Grebenstein
- Institute of Environmental Sciences, Leiden University, Leiden, The Netherlands.
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78
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Hartman Y, Uwimana B, Hooftman DAP, Schranz ME, van de Wiel CCM, Smulders MJM, Visser RGF, van Tienderen PH. Genomic and environmental selection patterns in two distinct lettuce crop-wild hybrid crosses. Evol Appl 2013; 6:569-84. [PMID: 23789025 PMCID: PMC3684739 DOI: 10.1111/eva.12043] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2012] [Accepted: 11/20/2012] [Indexed: 11/29/2022] Open
Abstract
Genomic selection patterns and hybrid performance influence the chance that crop (trans)genes can spread to wild relatives. We measured fitness(-related) traits in two different field environments employing two different crop–wild crosses of lettuce. We performed quantitative trait loci (QTL) analyses and estimated the fitness distribution of early- and late-generation hybrids. We detected consistent results across field sites and crosses for a fitness QTL at linkage group 7, where a selective advantage was conferred by the wild allele. Two fitness QTL were detected on linkage group 5 and 6, which were unique to one of the crop–wild crosses. Average hybrid fitness was lower than the fitness of the wild parent, but several hybrid lineages outperformed the wild parent, especially in a novel habitat for the wild type. In early-generation hybrids, this may partly be due to heterosis effects, whereas in late-generation hybrids transgressive segregation played a major role. The study of genomic selection patterns can identify crop genomic regions under negative selection across multiple environments and cultivar–wild crosses that might be applicable in transgene mitigation strategies. At the same time, results were cultivar-specific, so that a case-by-case environmental risk assessment is still necessary, decreasing its general applicability.
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Affiliation(s)
- Yorike Hartman
- Institute for Biodiversity and Ecosystem Dynamics, Universiteit van Amsterdam Amsterdam, The Netherlands
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79
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Parisod C, Definod C, Sarr A, Arrigo N, Felber F. Genome-specific introgression between wheat and its wild relative Aegilops triuncialis. J Evol Biol 2012. [PMID: 23205963 DOI: 10.1111/jeb.12040] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Introgression of sequences from crop species in wild relatives is of fundamental and practical concern. Here, we address gene flow between cultivated wheat and its widespread polyploid relative, Aegilops triuncialis, using 12 EST-SSR markers mapped on wheat chromosomes. The presence of wheat diagnostic alleles in natural populations of the barbed goatgrass growing in proximity to cultivated fields highlights that substantial gene flow occurred when both species coexisted. Furthermore, loci from the A subgenome of wheat were significantly less introgressed than sequences from other subgenomes, indicating differential introgression into Ae. triuncialis. Gene flow between such species sharing nonhomeologous chromosomes addresses the evolutionary outcomes of hybridization and may be important for efficient gene containment.
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Affiliation(s)
- C Parisod
- Laboratory of Evolutionary Botany, Institute of Biology, University of Neuchâtel, Neuchâtel, Switzerland.
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80
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Tsuda M, Okuzaki A, Kaneko Y, Tabei Y. Persistent C genome chromosome regions identified by SSR analysis in backcross progenies between Brassica juncea and B. napus. BREEDING SCIENCE 2012; 62:328-333. [PMID: 23341746 PMCID: PMC3528329 DOI: 10.1270/jsbbs.62.328] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/21/2012] [Accepted: 10/30/2012] [Indexed: 06/01/2023]
Abstract
Given that feral transgenic canola (Brassica napus) from spilled seeds has been found outside of farmer's fields and that B. juncea is distributed worldwide, it is possible that introgression to B. juncea from B. napus has occurred. To investigate such introgression, we characterized the persistence of B. napus C genome chromosome (C-chromosome) regions in backcross progenies by B. napus C-chromosome specific simple sequence repeat (SSR) markers. We produced backcross progenies from B. juncea and F(1) hybrid of B. juncea × B. napus to evaluate persistence of C-chromosome region, and screened 83 markers from a set of reported C-chromosome specific SSR markers. Eighty-five percent of the SSR markers were deleted in the BC(1) obtained from B. juncea × F(1) hybrid, and this BC(1) exhibited a plant type like that of B. juncea. Most markers were deleted in BC(2) and BC(3) plants, with only two markers persisting in the BC(3). These results indicate a small possibility of persistence of C-chromosome regions in our backcross progenies. Knowledge about the persistence of B. napus C-chromosome regions in backcross progenies may contribute to shed light on gene introgression.
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Affiliation(s)
- Mai Tsuda
- Genetically Modified Organism Research Center, National Institute of Agrobiological Sciences (NIAS), 2-1-2 Kan-nondai, Tsukuba, Ibaraki 305-8602, Japan
| | - Ayako Okuzaki
- Genetically Modified Organism Research Center, National Institute of Agrobiological Sciences (NIAS), 2-1-2 Kan-nondai, Tsukuba, Ibaraki 305-8602, Japan
| | - Yukio Kaneko
- Laboratory of Plant Breeding, Faculty of Agriculture, Utsunomiya University, 350 Minemachi, Utsunomiya, Tochigi 321-8505, Japan
| | - Yutaka Tabei
- Genetically Modified Organism Research Center, National Institute of Agrobiological Sciences (NIAS), 2-1-2 Kan-nondai, Tsukuba, Ibaraki 305-8602, Japan
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81
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Ghosh A, Meirmans PG, Haccou P. Quantifying introgression risk with realistic population genetics. Proc Biol Sci 2012; 279:4747-54. [PMID: 23055068 DOI: 10.1098/rspb.2012.1907] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Introgression is the permanent incorporation of genes from the genome of one population into another. This can have severe consequences, such as extinction of endemic species, or the spread of transgenes. Quantification of the risk of introgression is an important component of genetically modified crop regulation. Most theoretical introgression studies aimed at such quantification disregard one or more of the most important factors concerning introgression: realistic genetical mechanisms, repeated invasions and stochasticity. In addition, the use of linkage as a risk mitigation strategy has not been studied properly yet with genetic introgression models. Current genetic introgression studies fail to take repeated invasions and demographic stochasticity into account properly, and use incorrect measures of introgression risk that can be manipulated by arbitrary choices. In this study, we present proper methods for risk quantification that overcome these difficulties. We generalize a probabilistic risk measure, the so-called hazard rate of introgression, for application to introgression models with complex genetics and small natural population sizes. We illustrate the method by studying the effects of linkage and recombination on transgene introgression risk at different population sizes.
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Affiliation(s)
- Atiyo Ghosh
- Institute of Environmental Sciences (CML), Leiden University, PO Box 9518, 2300 RA Leiden, The Netherlands.
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82
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Uwimana B, Smulders MJM, Hooftman DAP, Hartman Y, van Tienderen PH, Jansen J, McHale LK, Michelmore RW, van de Wiel CCM, Visser RGF. Hybridization between crops and wild relatives: the contribution of cultivated lettuce to the vigour of crop-wild hybrids under drought, salinity and nutrient deficiency conditions. TAG. THEORETICAL AND APPLIED GENETICS. THEORETISCHE UND ANGEWANDTE GENETIK 2012; 125:1097-111. [PMID: 22660630 PMCID: PMC3442173 DOI: 10.1007/s00122-012-1897-4] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/03/2011] [Accepted: 05/11/2012] [Indexed: 05/10/2023]
Abstract
With the development of transgenic crop varieties, crop-wild hybridization has received considerable consideration with regard to the potential of transgenes to be transferred to wild species. Although many studies have shown that crops can hybridize with their wild relatives and that the resulting hybrids may show improved fitness over the wild parents, little is still known on the genetic contribution of the crop parent to the performance of the hybrids. In this study, we investigated the vigour of lettuce hybrids using 98 F(2:3) families from a cross between cultivated lettuce and its wild relative Lactuca serriola under non-stress conditions and under drought, salinity and nutrient deficiency. Using single nucleotide polymorphism markers, we mapped quantitative trait loci associated with plant vigour in the F(2:3) families and determined the allelic contribution of the two parents. Seventeen QTLs (quantitative trait loci) associated with vigour and six QTLs associated with the accumulation of ions (Na(+), Cl(-) and K(+)) were mapped on the nine linkage groups of lettuce. Seven of the vigour QTLs had a positive effect from the crop allele and six had a positive effect from the wild allele across treatments, and four QTLs had a positive effect from the crop allele in one treatment and from the wild allele in another treatment. Based on the allelic effect of the QTLs and their location on the genetic map, we could suggest genomic locations where transgene integration should be avoided when aiming at the mitigation of its persistence once crop-wild hybridization takes place.
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Affiliation(s)
| | | | | | - Yorike Hartman
- IBED, Universiteit van Amsterdam, Amsterdam, The Netherlands
| | | | | | - Leah K. McHale
- Department of Horticulture and Crop Science, Ohio State University, Columbus, USA
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Hartman Y, Hooftman DAP, Uwimana B, van de Wiel CCM, Smulders MJM, Visser RGF, van Tienderen PH. Genomic regions in crop-wild hybrids of lettuce are affected differently in different environments: implications for crop breeding. Evol Appl 2012; 5:629-40. [PMID: 23028403 PMCID: PMC3461145 DOI: 10.1111/j.1752-4571.2012.00240.x] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2011] [Accepted: 12/21/2011] [Indexed: 11/30/2022] Open
Abstract
Many crops contain domestication genes that are generally considered to lower fitness of crop-wild hybrids in the wild environment. Transgenes placed in close linkage with such genes would be less likely to spread into a wild population. Therefore, for environmental risk assessment of GM crops, it is important to know whether genomic regions with such genes exist, and how they affect fitness. We performed quantitative trait loci (QTL) analyses on fitness(-related) traits in two different field environments employing recombinant inbred lines from a cross between cultivated Lactuca sativa and its wild relative Lactuca serriola. We identified a region on linkage group 5 where the crop allele consistently conferred a selective advantage (increasing fitness to 212% and 214%), whereas on linkage group 7, a region conferred a selective disadvantage (reducing fitness to 26% and 5%), mainly through delaying flowering. The probability for a putative transgene spreading would therefore depend strongly on the insertion location. Comparison of these field results with greenhouse data from a previous study using the same lines showed considerable differences in QTL patterns. This indicates that care should be taken when extrapolating experiments from the greenhouse, and that the impact of domestication genes has to be assessed under field conditions.
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Affiliation(s)
- Yorike Hartman
- Institute for Biodiversity and Ecosystem Dynamics, Universiteit van Amsterdam Amsterdam, The Netherlands
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84
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Yang X, Wang F, Su J, Lu BR. Limited fitness advantages of crop-weed hybrid progeny containing insect-resistant transgenes (Bt/CpTI) in transgenic rice field. PLoS One 2012; 7:e41220. [PMID: 22815975 PMCID: PMC3398902 DOI: 10.1371/journal.pone.0041220] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2012] [Accepted: 06/18/2012] [Indexed: 11/21/2022] Open
Abstract
Background The spread of insect-resistance transgenes from genetically engineered (GE) rice to its coexisting weedy rice (O. sativa f. spontanea) populations via gene flow creates a major concern for commercial GE rice cultivation. Transgene flow to weedy rice seems unavoidable. Therefore, characterization of potential fitness effect brought by the transgenes is essential to assess environmental consequences caused by crop-weed transgene flow. Methodology/Principal Findings Field performance of fitness-related traits was assessed in advanced hybrid progeny of F4 generation derived from a cross between an insect-resistant transgenic (Bt/CpTI) rice line and a weedy strain. The performance of transgene-positive hybrid progeny was compared with the transgene-negative progeny and weedy parent in pure and mixed planting of transgenic and nontransgenic plants under environmental conditions with natural vs. low insect pressure. Results showed that under natural insect pressure the insect-resistant transgenes could effectively suppress target insects and bring significantly increased fitness to transgenic plants in pure planting, compared with nontransgenic plants (including weedy parent). In contrast, no significant differences in fitness were detected under low insect pressure. However, such increase in fitness was not detected in the mixed planting of transgenic and nontransgenic plants due to significantly reduced insect pressure. Conclusions/Significance Insect-resistance transgenes may have limited fitness advantages to hybrid progeny resulted from crop-weed transgene flow owning to the significantly reduced ambient target insect pressure when an insect-resistant GE crop is grown. Given that the extensive cultivation of an insect-resistant GE crop will ultimately reduce the target insect pressure, the rapid spread of insect-resistance transgenes in weedy populations in commercial GE crop fields may be not likely to happen.
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Affiliation(s)
- Xiao Yang
- Ministry of Education Key Laboratory for Biodiversity Science and Ecological Engineering, Department of Ecology and Evolutionary Biology, Fudan University, Shanghai, China
| | - Feng Wang
- Fujian Province Key Laboratory of Genetic Engineering for Agriculture, Fujian Academy of Agricultural Sciences, Fuzhou, China
| | - Jun Su
- Fujian Province Key Laboratory of Genetic Engineering for Agriculture, Fujian Academy of Agricultural Sciences, Fuzhou, China
| | - Bao-Rong Lu
- Ministry of Education Key Laboratory for Biodiversity Science and Ecological Engineering, Department of Ecology and Evolutionary Biology, Fudan University, Shanghai, China
- * E-mail:
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85
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Fang S, Yukilevich R, Chen Y, Turissini DA, Zeng K, Boussy IA, Wu CI. Incompatibility and competitive exclusion of genomic segments between sibling Drosophila species. PLoS Genet 2012; 8:e1002795. [PMID: 22761593 PMCID: PMC3386244 DOI: 10.1371/journal.pgen.1002795] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2011] [Accepted: 05/15/2012] [Indexed: 11/22/2022] Open
Abstract
The extent and nature of genetic incompatibilities between incipient races and sibling species is of fundamental importance to our view of speciation. However, with the exception of hybrid inviability and sterility factors, little is known about the extent of other, more subtle genetic incompatibilities between incipient species. Here we experimentally demonstrate the prevalence of such genetic incompatibilities between two young allopatric sibling species, Drosophila simulans and D. sechellia. Our experiments took advantage of 12 introgression lines that carried random introgressed D. sechellia segments in different parts of the D. simulans genome. First, we found that these introgression lines did not show any measurable sterility or inviability effects. To study if these sechellia introgressions in a simulans background contained other fitness consequences, we competed and genetically tracked the marked alleles within each introgression against the wild-type alleles for 20 generations. Strikingly, all marked D. sechellia introgression alleles rapidly decreased in frequency in only 6 to 7 generations. We then developed computer simulations to model our competition results. These simulations indicated that selection against D. sechellia introgression alleles was high (average s = 0.43) and that the marker alleles and the incompatible alleles did not separate in 78% of the introgressions. The latter result likely implies that most introgressions contain multiple genetic incompatibilities. Thus, this study reveals that, even at early stages of speciation, many parts of the genome diverge to a point where introducing foreign elements has detrimental fitness consequences, but which cannot be seen using standard sterility and inviability assays. Determining the extent of genomic incompatibilities is a pivotal issue in understanding the process of speciation. A controversial topic that has recently sparked debate is whether there are few isolated genetic regions (so-called “genomic islands of speciation”) or extensive genetic regions (“genomic continents of speciation”) responsible for species divergence. To answer this question, most work has focused on species divergence at the DNA sequence level. Here, we present a new perspective by shifting the focus to the fitness and functional aspects of foreign genomic introgression. To illustrate our point, we performed an introgression experiment on two sibling species, D. sechellia and D. simulans. After introgressing random genomic segments of D. sechellia into D. simulans genetic background, a 20-generation competition experiment revealed that, even at the early stages of speciation, there are virtually always detrimental fitness consequences to introducing random foreign elements from one genome to another. This implies that incipient speciation may be characterized by widespread accumulation of genomic incompatibilities rather than a few isolated genes. This study shows that we should move beyond the sterility and inviability assays in order to understand the full extent of genetic incompatibilities during speciation.
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Affiliation(s)
- Shu Fang
- Biodiversity Research Center, Academia Sinica, Taipei, Taiwan, Republic of China
- * E-mail: (SF); (RY)
| | - Roman Yukilevich
- Department of Ecology and Evolution, University of Chicago, Chicago, Illinois, United States of America
- Biology Department, Union College, Schenectady, New York, United States of America
- * E-mail: (SF); (RY)
| | - Ying Chen
- Department of Ecology and Evolution, University of Chicago, Chicago, Illinois, United States of America
- Department of Biology, Loyola University Chicago, Chicago, Illinois, United States of America
| | - David A. Turissini
- Department of Ecology and Evolution, University of Chicago, Chicago, Illinois, United States of America
| | - Kai Zeng
- Department of Ecology and Evolution, University of Chicago, Chicago, Illinois, United States of America
- State Key Laboratory of Biocontrol, School of Life Sciences, Sun Yat-sen (Zhongshan) University, Guangzhou, People's Republic of China
| | - Ian A. Boussy
- Department of Biology, Loyola University Chicago, Chicago, Illinois, United States of America
| | - Chung-I. Wu
- Department of Ecology and Evolution, University of Chicago, Chicago, Illinois, United States of America
- State Key Laboratory of Biocontrol, School of Life Sciences, Sun Yat-sen (Zhongshan) University, Guangzhou, People's Republic of China
- Beijing Institute of Genomics, Chinese Academy of Sciences, Beijing, People's Republic of China
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86
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Liu YB, Tang ZX, Darmency H, Stewart CN, Di K, Wei W, Ma KP. The effects of seed size on hybrids formed between oilseed rape (Brassica napus) and wild brown mustard (B. juncea). PLoS One 2012; 7:e39705. [PMID: 22745814 PMCID: PMC3382164 DOI: 10.1371/journal.pone.0039705] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2011] [Accepted: 05/25/2012] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND Seed size has significant implications in ecology, because of its effects on plant fitness. The hybrid seeds that result from crosses between crops and their wild relatives are often small, and the consequences of this have been poorly investigated. Here we report on plant performance of hybrid and its parental transgenic oilseed rape (Brassica napus) and wild B. juncea, all grown from seeds sorted into three seed-size categories. METHODOLOGY/PRINCIPAL FINDINGS Three seed-size categories were sorted by seed diameter for transgenic B. napus, wild B. juncea and their transgenic and non-transgenic hybrids. The seeds were sown in a field at various plant densities. Globally, small-seeded plants had delayed flowering, lower biomass, fewer flowers and seeds, and a lower thousand-seed weight. The seed-size effect varied among plant types but was not affected by plant density. There was no negative effect of seed size in hybrids, but it was correlated with reduced growth for both parents. CONCLUSIONS Our results imply that the risk of further gene flow would probably not be mitigated by the small size of transgenic hybrid seeds. No fitness cost was detected to be associated with the Bt-transgene in this study.
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Affiliation(s)
- Yong-bo Liu
- State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Sciences, Beijing, China
- UMR1347 Agroécologie, Institut National de la Recherche Agronomique, Dijon, France
- State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing, China
| | - Zhi-xi Tang
- State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Sciences, Beijing, China
| | - Henri Darmency
- UMR1347 Agroécologie, Institut National de la Recherche Agronomique, Dijon, France
| | - C. Neal Stewart
- Department of Plant Sciences, University of Tennessee, Knoxville, Tennessee, United States of America
| | - Kun Di
- State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Sciences, Beijing, China
- PetroChina Tarim Oilfield Company, Korler, Xinjiang, China
| | - Wei Wei
- State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Sciences, Beijing, China
| | - Ke-ping Ma
- State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Sciences, Beijing, China
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87
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Uwimana B, D'Andrea L, Felber F, Hooftman DAP, Den Nijs HCM, Smulders MJM, Visser RGF, Van De Wiel CCM. A Bayesian analysis of gene flow from crops to their wild relatives: cultivated (Lactuca sativa L.) and prickly lettuce (L. serriola L.) and the recent expansion of L. serriola in Europe. Mol Ecol 2012; 21:2640-54. [PMID: 22512715 DOI: 10.1111/j.1365-294x.2012.05489.x] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Interspecific gene flow can lead to the formation of hybrid populations that have a competitive advantage over the parental populations, even for hybrids from a cross between crops and wild relatives. Wild prickly lettuce (Lactuca serriola) has recently expanded in Europe and hybridization with the related crop species (cultivated lettuce, L. sativa) has been hypothesized as one of the mechanisms behind this expansion. In a basically selfing species, such as lettuce, assessing hybridization in natural populations may not be straightforward. Therefore, we analysed a uniquely large data set of plants genotyped with SSR (simple sequence repeat) markers with two programs for Bayesian population genetic analysis, STRUCTURE and NewHybrids. The data set comprised 7738 plants, including a complete genebank collection, which provided a wide coverage of cultivated germplasm and a fair coverage of wild accessions, and a set of wild populations recently sampled across Europe. STRUCTURE analysis inferred the occurrence of hybrids at a level of 7% across Europe. NewHybrids indicated these hybrids to be advanced selfed generations of a hybridization event or of one backcross after such an event, which is according to expectations for a basically selfing species. These advanced selfed generations could not be detected effectively with crop-specific alleles. In the northern part of Europe, where the expansion of L. serriola took place, the fewest putative hybrids were found. Therefore, we conclude that other mechanisms than crop/wild gene flow, such as an increase in disturbed habitats and/or climate warming, are more likely explanations for this expansion.
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88
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Gene deletor: a new tool to address gene flow and food safety concerns over transgenic crop plants. ACTA ACUST UNITED AC 2012. [DOI: 10.1007/s11515-012-1195-1] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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89
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Uwimana B, Smulders MJM, Hooftman DAP, Hartman Y, van Tienderen PH, Jansen J, McHale LK, Michelmore RW, Visser RGF, van de Wiel CCM. Crop to wild introgression in lettuce: following the fate of crop genome segments in backcross populations. BMC PLANT BIOLOGY 2012; 12:43. [PMID: 22448748 PMCID: PMC3384248 DOI: 10.1186/1471-2229-12-43] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/18/2011] [Accepted: 03/26/2012] [Indexed: 05/09/2023]
Abstract
BACKGROUND After crop-wild hybridization, some of the crop genomic segments may become established in wild populations through selfing of the hybrids or through backcrosses to the wild parent. This constitutes a possible route through which crop (trans)genes could become established in natural populations. The likelihood of introgression of transgenes will not only be determined by fitness effects from the transgene itself but also by the crop genes linked to it. Although lettuce is generally regarded as self-pollinating, outbreeding does occur at a low frequency. Backcrossing to wild lettuce is a likely pathway to introgression along with selfing, due to the high frequency of wild individuals relative to the rarely occurring crop-wild hybrids. To test the effect of backcrossing on the vigour of inter-specific hybrids, Lactuca serriola, the closest wild relative of cultivated lettuce, was crossed with L. sativa and the F(1) hybrid was backcrossed to L. serriola to generate BC(1) and BC(2) populations. Experiments were conducted on progeny from selfed plants of the backcrossing families (BC(1)S(1) and BC(2)S(1)). Plant vigour of these two backcrossing populations was determined in the greenhouse under non-stress and abiotic stress conditions (salinity, drought, and nutrient deficiency). RESULTS Despite the decreasing contribution of crop genomic blocks in the backcross populations, the BC(1)S(1) and BC(2)S(1) hybrids were characterized by a substantial genetic variation under both non-stress and stress conditions. Hybrids were identified that performed equally or better than the wild genotypes, indicating that two backcrossing events did not eliminate the effect of the crop genomic segments that contributed to the vigour of the BC(1) and BC(2) hybrids. QTLs for plant vigour under non-stress and the various stress conditions were detected in the two populations with positive as well as negative effects from the crop. CONCLUSION As it was shown that the crop contributed QTLs with either a positive or a negative effect on plant vigour, we hypothesize that genomic regions exist where transgenes could preferentially be located in order to mitigate their persistence in natural populations through genetic hitchhiking.
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Affiliation(s)
- Brigitte Uwimana
- Wageningen UR Plant Breeding, Postbus 386, 6700AJ Wageningen, the Netherlands
| | - Marinus JM Smulders
- Wageningen UR Plant Breeding, Postbus 16, 6700AA Wageningen, the Netherlands
| | - Danny AP Hooftman
- Centre for Ecology & Hydrology, Maclean Building, Benson Lane, Crowmarsh Gifford, Wallingford, Oxfordshire, OX10 8BB, UK
| | - Yorike Hartman
- Institute for Biodiversity and Ecosystem Dynamics, University of Amsterdam, Postbus 94248, 1090 GE Amsterdam, the Netherlands
| | - Peter H van Tienderen
- Institute for Biodiversity and Ecosystem Dynamics, University of Amsterdam, Postbus 94248, 1090 GE Amsterdam, the Netherlands
| | - Johannes Jansen
- Wageningen UR Plant Biometris, Postbus 100, 6700AC Wageningen, the Netherlands
| | - Leah K McHale
- Department of Horticulture and Crop Science, The Ohio State University, Columbus, OH 43210, USA
| | - Richard W Michelmore
- Genome Center and Department of Plant Sciences, University of California Davis, Davis, CA 95616-8816, USA
| | - Richard GF Visser
- Wageningen UR Plant Breeding, Postbus 386, 6700AJ Wageningen, the Netherlands
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90
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DiFazio SP, Leonardi S, Slavov GT, Garman SL, Adams WT, Strauss SH. Gene flow and simulation of transgene dispersal from hybrid poplar plantations. THE NEW PHYTOLOGIST 2012; 193:903-915. [PMID: 22221193 DOI: 10.1111/j.1469-8137.2011.04012.x] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Gene flow is a primary determinant of potential ecological impacts of transgenic trees. However, gene flow is a complex process that must be assessed in the context of realistic genetic, management, and environmental conditions. We measured gene flow from hybrid poplar plantations using morphological and genetic markers, and developed a spatially explicit landscape model to simulate pollination, dispersal, establishment, and mortality in the context of historical and projected disturbance and land-use regimes. Most pollination and seed establishment occurred within 450 m of the source, with a very long tail. Modeled transgene flow was highly context-dependent, strongly influenced by the competitive effects of transgenes, transgenic fertility, plantation rotation length, disturbance regime, and spatial and temporal variation in selection. The use of linked infertility genes even if imperfect, substantially reduced transgene flow in a wide range of modeled scenarios. The significance of seed and vegetative dispersal was highly dependent on plantation size. Our empirical and modeling studies suggest that transgene spread can be spatially extensive. However, the amount of spread is highly dependent on ecological and management context, and can be greatly limited or prevented by management or mitigation genes such as those that cause sexual infertility.
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Affiliation(s)
- Stephen P DiFazio
- Department of Biology, West Virginia University, Morgantown, WV 26506-6057, USA
| | - Stefano Leonardi
- Dipartimento di Scienze Ambientali, Università di Parma, 43100 Parma, Italy
| | - Gancho T Slavov
- Department of Biology, West Virginia University, Morgantown, WV 26506-6057, USA
- Department of Dendrology, University of Forestry, Sofia 1756, Bulgaria
- Institute of Biological, Environmental and Rural Sciences, Aberystwyth University, Aberystwyth SY23 3EB, UK
| | - Steven L Garman
- National Park Service, PO Box 848, Moab, UT 84532, USA
- Department of Forest Ecosystems and Society, Oregon State University, 3180 SW Jefferson Way, Corvallis, OR 97331, USA
| | - W Thomas Adams
- Department of Forest Ecosystems and Society, Oregon State University, 3180 SW Jefferson Way, Corvallis, OR 97331, USA
| | - Steven H Strauss
- Department of Forest Ecosystems and Society, Oregon State University, 3180 SW Jefferson Way, Corvallis, OR 97331, USA
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91
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Kitamoto N, Kaga A, Kuroda Y, Ohsawa R. A model to predict the frequency of integration of fitness-related QTLs from cultivated to wild soybean. Transgenic Res 2012; 21:131-8. [PMID: 21544624 DOI: 10.1007/s11248-011-9516-8] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2010] [Accepted: 04/19/2011] [Indexed: 11/27/2022]
Abstract
With the proliferation of genetically modified (GM) products and the almost exponential growth of land use for GM crops, there is a growing need to develop quantitative approaches to estimating the risk of escape of transgenes into wild populations of crop relatives by natural hybridization. We assessed the risk of transgene escape by constructing a population genetic model based on information on fitness-related QTLs obtained from an F (2) population of wild soybean G. soja × cultivated soybean Glycine max. Simulation started with ten F (1) and 990 wild soybeans reproducing by selfing or outcrossing. Seed production was determined from the genetic effects of two QTLs for number of seeds (SN). Each seed survived winter according to the maternal genotype at three QTLs for winter survival (WS). We assumed that one neutral transgene was inserted at various sites and calculated its extinction rate. The presence of G. max alleles at SN and WS QTLs significantly decreased the probability of introgression of the neutral transgene at all insertion sites equally. The presence of G. max alleles at WS QTLs lowered the risk more than their presence at SN QTLs. Although most model studies have concentrated only on genotypic effects of transgenes, we show that the presence of fitness-related domestication genes has a large effect on the risk of transgene escape. Our model offers the advantage of considering the effects of both domestication genes and a transgene, and they can be widely applied to other wild × crop relative complexes.
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Affiliation(s)
- N Kitamoto
- Laboratory of Plant Breeding, Graduate School of Life and Environmental Sciences, University of Tsukuba, 1-1-1 Tennoudai, Tsukuba, Ibaraki, 305-8572, Japan
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92
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Jiang Z, Xia H, Basso B, Lu BR. Introgression from cultivated rice influences genetic differentiation of weedy rice populations at a local spatial scale. TAG. THEORETICAL AND APPLIED GENETICS. THEORETISCHE UND ANGEWANDTE GENETIK 2012; 124:309-322. [PMID: 21947325 DOI: 10.1007/s00122-011-1706-5] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/02/2011] [Accepted: 09/07/2011] [Indexed: 05/31/2023]
Abstract
Hybridization and introgression can play an important role in genetic differentiation and adaptive evolution of plant species. For example, a conspecific feral species may frequently acquire new alleles from its coexisting crops via introgression. However, little is known about this process. We analyzed 24 weedy rice (Oryza sativa f. spontanea) populations and their coexisting rice cultivars from northern Italy to study their genetic differentiation, outcrossing, and introgression based on microsatellite polymorphisms. A total of 576 maternal plants representing 24 weedy populations were used to estimate their genetic differentiation, and 5,395 progeny (seedlings) derived from 299 families of 15 selected populations were included to measure outcrossing rates. Considerable genetic differentiation (F (st) = 0.26) was detected among weedy rice populations, although the differentiation was not associated with the spatial pattern of the populations. Private alleles (28%) were identified in most populations that exhibited a multiple cluster assignments, indicating stronger genetic affinities of some weedy populations. Outcrossing rates were greatly variable and positively correlated (R (2) = 0.34, P = 0.02) with the private alleles of the corresponding populations. Paternity analysis suggested that ~15% of paternal specific alleles, a considerable portion of which was found to be crop-specific, were acquired from the introgression of the coexisting rice cultivars. Frequent allelic introgression into weedy populations resulting from outcrossing with nearby cultivars determines the private alleles of local feral populations, possibly leading to their genetic differentiation. Introgression from a crop may play an important role in the adaptive evolution of feral populations.
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Affiliation(s)
- Zhuxi Jiang
- Ministry of Education Key Laboratory for Biodiversity and Ecological Engineering, Institute of Biodiversity Science, Fudan University, Handan Road 220, Shanghai, 200433, China
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93
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Hovick SM, Campbell LG, Snow AA, Whitney KD. Hybridization alters early life-history traits and increases plant colonization success in a novel region. Am Nat 2011; 179:192-203. [PMID: 22218309 DOI: 10.1086/663684] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
Hybridization is hypothesized to promote invasiveness, but empirical tests comparing the performance of hybrid taxa versus parental taxa in novel regions are lacking. We experimentally compared colonization ability of populations of wild radish (Raphanus raphanistrum) with populations of advanced-generation hybrids between wild radish and cultivated radish (Raphanus sativus) in a southeast Texas pasture, well beyond the known invasive range of hybrid radish. We also manipulated the strength of interspecific competition to better generalize across variable environments. In both competitive environments, hybrid populations produced at least three times more seeds than did wild radish populations, a distinction that was driven by greater hybrid seedling emergence, earlier hybrid emergence, and more hybrid seedlings surviving to flower, rather than by greater individual fecundity. Flowering duration in hybrids was less negatively affected by competition than it was in wild radish, while early emergence was associated with subsequent high seed output in both biotypes. Our data show that hybridization can enhance colonization success in a novel region and, by comparison with previous studies, that the life-history traits enhancing hybrid success can differ across regions, even for lineages originating from the same hybridization event. These results imply a much larger arena for hybrid success than previously appreciated.
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Affiliation(s)
- Stephen M Hovick
- Department of Ecology and Evolutionary Biology, Rice University, Houston, Texas 77005, USA.
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94
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Mamidi S, Rossi M, Annam D, Moghaddam S, Lee R, Papa R, McClean P. Investigation of the domestication of common bean (Phaseolus vulgaris) using multilocus sequence data. FUNCTIONAL PLANT BIOLOGY : FPB 2011; 38:953-967. [PMID: 32480954 DOI: 10.1071/fp11124] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/21/2011] [Accepted: 09/15/2011] [Indexed: 05/24/2023]
Abstract
Multilocus sequence data collected from domesticated and related wild relatives provides a rich source of information on the effect of human selection on the diversity and adaptability of a species to complex environments. To evaluate the domestication history of common bean (Phaseolus vulgaris L.), multilocus sequence data from landraces representing the various races within the Middle American (MA) and Andean gene pools was evaluated. Across 13 loci, nucleotide diversity was similar between landraces and wild germplasm in both gene pools. The diversity data were evaluated using the approximate Bayesian computation approach to test multiple domestication models and estimate population demographic parameters. A model with a single domestication event coupled with bidirectional migration between wild and domesticated genotypes fitted the data better than models consisting of two or three domestication events in each genepool. The effective bottleneck population size was ~50% of the base population in each genepool. The bottleneck began ~8200 and ~8500 years before present and ended at ~6300 and ~7000 years before present in MA and Andean gene pools respectively. Linkage disequilibrium decayed to a greater extent in the MA genepool. Given the (1) geographical adaptation bottleneck in each wild gene pool, (2) a subsequent domestication bottleneck within each gene pool, (3) differentiation into gene-pool specific races and (4) variable extents of linkage disequilibrium, association mapping experiments for common bean would more appropriately be performed within each genepool.
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Affiliation(s)
- Sujan Mamidi
- North Dakota State University, Department of Plant Sciences, Fargo, ND 58102, USA
| | - Monica Rossi
- Università Politecnica delle Marche, Scienze Ambientali e delle Produzioni Vegetali, Ancona, Italy
| | - Deepti Annam
- North Dakota State University, Department of Statistics, Fargo, ND 58102, USA
| | - Samira Moghaddam
- North Dakota State University, Department of Plant Sciences, Fargo, ND 58102, USA
| | - Rian Lee
- North Dakota State University, Department of Plant Sciences, Fargo, ND 58102, USA
| | - Roberto Papa
- Università Politecnica delle Marche, Scienze Ambientali e delle Produzioni Vegetali, Ancona, Italy
| | - Phillip McClean
- North Dakota State University, Department of Plant Sciences, Fargo, ND 58102, USA
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95
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Londo JP, Bollman MA, Sagers CL, Lee EH, Watrud LS. Changes in fitness-associated traits due to the stacking of transgenic glyphosate resistance and insect resistance in Brassica napus L. Heredity (Edinb) 2011; 107:328-37. [PMID: 21427753 PMCID: PMC3182500 DOI: 10.1038/hdy.2011.19] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2010] [Revised: 02/05/2011] [Accepted: 02/18/2011] [Indexed: 11/09/2022] Open
Abstract
Increasingly, genetically modified crops are being developed to express multiple 'stacked' traits for different types of transgenes, for example, herbicide resistance, insect resistance, crop quality and tolerance to environmental stresses. The release of crops that express multiple traits could result in ecological changes in weedy environments if feral crop plants or hybrids formed with compatible weeds results in more competitive plants outside of agriculture. To examine the effects of combining transgenes, we developed a stacked line of canola (Brassica napus L.) from a segregating F(2) population that expresses both transgenic glyphosate resistance (CP4 EPSPS) and lepidopteran insect resistance (Cry1Ac). Fitness-associated traits were evaluated between this stacked genotype and five other Brassica genotypes in constructed mesocosm plant communities exposed to insect herbivores (Plutella xylostella L.) or glyphosate-drift. Vegetative biomass, seed production and relative fecundity were all reduced in stacked trait plants when compared with non-transgenic plants in control treatments, indicating potential costs of expressing multiple transgenes without selection pressure. Although costs of the transgenes were offset by selective treatment, the stacked genotype continued to produce fewer seeds than either single transgenic line. However, the increase in fitness of the stacked genotype under selective pressure contributed to an increased number of seeds within the mesocosm community carrying unselected, hitchhiking transgenes. These results demonstrate that the stacking of these transgenes in canola results in fitness costs and benefits that are dependent on the type and strength of selection pressure, and could also contribute to changes in plant communities through hitchhiking of unselected traits.
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Affiliation(s)
- J P Londo
- National Research Council, Corvallis, OR, USA.
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96
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Gutierrez A, Cantamutto M, Poverene M. Persistence of sunflower crop traits and fitness in Helianthus petiolaris populations. PLANT BIOLOGY (STUTTGART, GERMANY) 2011; 13:821-30. [PMID: 21815987 DOI: 10.1111/j.1438-8677.2010.00433.x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
Transgenic plants have increased interest in the study of crop gene introgression in wild populations. Genes (or transgenes) conferring adaptive advantages persist in introgressed populations, enhancing competitiveness of wild or weedy plants. This represents an ecological risk that could increase problems of weed control. Introgression of cultivar alleles into wild plant populations via crop-wild hybridisations is primarily governed by their fitness effect. To evaluate this, we studied the second generation of seven wild-crop interspecific hybrids between weedy Helianthus petiolaris and cultivated sunflower, H. annuus var. macrocarpus. The second generation comprised open-pollinated progeny and backcrosses to the wild parent, mimicking crosses that occur in natural situations. We compared a number of morphological, life history and fitness traits. Multivariate analysis showed that the parental species H. annuus and H. petiolaris differed in a number of morphological traits, while the second hybrid generation between them was intermediate. Sunflower crop introgression lowered fitness of interspecific hybrids, but fitness parameters tended to recover in the following generation. Relative frequency of wild/weedy and introgressed plants was estimated through four generations, based on male and female parent fitness. In spite of several negative selection coefficients observed in the second generation, introgressed plants could be detected in stands of <100 weedy H. petiolaris populations. The rapid recovery of fecundity parameters leads to prediction that any trait conferring an ecological advantage will diffuse into the wild or weedy population, even if F1 hybrids have low fitness.
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Affiliation(s)
- A Gutierrez
- Centro De Recursos Naturales de la Zona Semiárida (CERZOS-CONICET), Bahía Blanca, Argentina.
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97
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Muraya MM, de Villiers S, Parzies HK, Mutegi E, Sagnard F, Kanyenji BM, Kiambi D, Geiger HH. Genetic structure and diversity of wild sorghum populations (Sorghum spp.) from different eco-geographical regions of Kenya. TAG. THEORETICAL AND APPLIED GENETICS. THEORETISCHE UND ANGEWANDTE GENETIK 2011; 123:571-83. [PMID: 21643817 DOI: 10.1007/s00122-011-1608-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/10/2011] [Accepted: 04/26/2011] [Indexed: 05/23/2023]
Abstract
Wild sorghums are extremely diverse phenotypically, genetically and geographically. However, there is an apparent lack of knowledge on the genetic structure and diversity of wild sorghum populations within and between various eco-geographical regions. This is a major obstacle to both their effective conservation and potential use in breeding programs. The objective of this study was to assess the genetic diversity and structure of wild sorghum populations across a range of eco-geographical conditions in Kenya. Sixty-two wild sorghum populations collected from the 4 main sorghum growing regions in Kenya were genotyped using 18 simple sequence repeat markers. The study showed that wild sorghum is highly variable with the Coast region displaying the highest diversity. Analysis of molecular variance showed a significant variance component within and among wild sorghum populations within regions. The genetic structure of wild sorghum populations indicated that gene flow is not restricted to populations within the same geographic region. A weak regional differentiation was found among populations, reflecting human intervention in shaping wild sorghum genetic structure through seed-mediated gene flow. The sympatric occurrence of wild and cultivated sorghums coupled with extensive seed-mediated gene flow, suggests a potential crop-to-wild gene flow and vice versa across the regions. Wild sorghum displayed a mixed mating system. The wide range of estimated outcrossing rates indicate that some environmental conditions may exist where self-fertilisation is favoured while others cross-pollination is more advantageous.
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Affiliation(s)
- Moses M Muraya
- Institute of Plant Breeding, Seed science and Population Genetics, University of Hohenheim, Fruwirthstrasse 21, 70599 Stuttgart, Germany.
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98
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Husaini AM, Rashid Z, Mir RUR, Aquil B. Approaches for gene targeting and targeted gene expression in plants. ACTA ACUST UNITED AC 2011; 2:150-62. [PMID: 22179193 DOI: 10.4161/gmcr.2.3.18605] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Transgenic science and technology are fundamental to state-of-the-art plant molecular genetics and crop improvement. The new generation of technology endeavors to introduce genes 'stably' into 'site-specific' locations and in 'single copy' without the integration of extraneous vector 'backbone' sequences or selectable markers and with a 'predictable and consistent' expression. Several similar strategies and technologies, which can push the development of 'smart' genetically modified plants with desirable attributes, as well as enhance their consumer acceptability, are discussed in this review.
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Affiliation(s)
- Amjad Masood Husaini
- Division of Plant Breeding and Genetics; Sher-e-Kashmir University of Agricultural Sciences and Technology of Kashmir; Shalimar, India.
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99
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Hooftman DAP, Flavell AJ, Jansen H, den Nijs HCM, Syed NH, Sørensen AP, Orozco-Ter Wengel P, van de Wiel CCM. Locus-dependent selection in crop-wild hybrids of lettuce under field conditions and its implication for GM crop development. Evol Appl 2011; 4:648-59. [PMID: 25568012 PMCID: PMC3352534 DOI: 10.1111/j.1752-4571.2011.00188.x] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2010] [Accepted: 03/28/2011] [Indexed: 12/01/2022] Open
Abstract
Gene escape from crops has gained much attention in the last two decades, as transgenes introgressing into wild populations could affect the latter's ecological characteristics. However, different genes have different likelihoods of introgression. The mixture of selective forces provided by natural conditions creates an adaptive mosaic of alleles from both parental species. We investigated segregation patterns after hybridization between lettuce (Lactuca sativa) and its wild relative, L. serriola. Three generations of hybrids (S1, BC1, and BC1S1) were grown in habitats mimicking the wild parent's habitat. As control, we harvested S1 seedlings grown under controlled conditions, providing very limited possibility for selection. We used 89 AFLP loci, as well as more recently developed dominant markers, 115 retrotransposon markers (SSAP), and 28 NBS loci linked to resistance genes. For many loci, allele frequencies were biased in plants exposed to natural field conditions, including over-representation of crop alleles for various loci. Furthermore, Linkage disequilibrium was locally changed, allegedly by selection caused by the natural field conditions, providing ample opportunity for genetic hitchhiking. Our study indicates that when developing genetically modified crops, a judicious selection of insertion sites, based on knowledge of selective (dis)advantages of the surrounding crop genome under field conditions, could diminish transgene persistence.
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Affiliation(s)
- Danny A P Hooftman
- Institute for Biodiversity and Ecosystem Dynamics, University of Amsterdam Amsterdam, The Netherlands ; Centre for Ecology and Hydrology Wallingford, UK
| | | | - Hans Jansen
- Biometris Wageningen UR, Wageningen, The Netherlands
| | - Hans C M den Nijs
- Institute for Biodiversity and Ecosystem Dynamics, University of Amsterdam Amsterdam, The Netherlands
| | | | | | - Pablo Orozco-Ter Wengel
- Institute for Biodiversity and Ecosystem Dynamics, University of Amsterdam Amsterdam, The Netherlands ; Keygene N.V Wageningen, The Netherlands
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100
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Chun YJ, Kim DI, Park KW, Kim HJ, Jeong SC, An JH, Cho KH, Back K, Kim HM, Kim CG. Gene flow from herbicide-tolerant GM rice and the heterosis of GM rice-weed F2 progeny. PLANTA 2011; 233:807-815. [PMID: 21212977 DOI: 10.1007/s00425-010-1339-y] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/18/2010] [Accepted: 12/13/2010] [Indexed: 05/30/2023]
Abstract
Gene flow from genetically modified (GM) crops to non-GM cultivars or weedy relatives may lead to the development of more aggressive weeds. We quantified the amount of gene flow from herbicide-tolerant GM rice (Protox GM, derived from the cultivar Dongjin) to three cultivars (Dongjin, Aranghyangchal and Hwaseong) and a weedy rice line. Gene flow frequency generally decreased with increasing distance from the pollen donor. At the shortest distance (0.5 m), we observed a maximum frequency (0.039%) of gene flow. We found that the cultivar Dongjin received the greatest amount of gene flow, with the second being weedy rice. Heterosis of F2 inbred progeny was also examined between Protox GM and weedy rice. We compared growth and reproduction between F2 progeny (homozygous or hemizygous for the Protox gene) and parental rice lines (GM and weedy rice). Here, transgene-homozygous F2 progeny was significantly taller and produced more seeds than the transgene-hemizygous F2 progeny and parental lines. Although the gene flow frequency was generally low, our results suggest that F2 progeny between GM and weedy relatives may exhibit heterosis.
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Affiliation(s)
- Young Jin Chun
- Bio-Evaluation Center, Korea Research Institute of Bioscience and Biotechnology, 685-1 Yangcheong-ri, Ochang-eup, Cheongwon-gun, Chungcheongbuk-do, 363-883, Republic of Korea
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