1
|
Westbrook AS, DiTommaso A. Hybridization in agricultural weeds: A review from ecological, evolutionary, and management perspectives. AMERICAN JOURNAL OF BOTANY 2023; 110:e16258. [PMID: 38031455 DOI: 10.1002/ajb2.16258] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/02/2023] [Revised: 10/22/2023] [Accepted: 10/23/2023] [Indexed: 12/01/2023]
Abstract
Agricultural weeds frequently hybridize with each other or with related crop species. Some hybrid weeds exhibit heterosis (hybrid vigor), which may be stabilized through mechanisms like genome duplication or vegetative reproduction. Even when heterosis is not stabilized, hybridization events diversify weed gene pools and often enable adaptive introgression. Consequently, hybridization may promote weed evolution and exacerbate weed-crop competition. However, hybridization does not always increase weediness. Even when viable and fertile, hybrid weeds sometimes prove unsuccessful in crop fields. This review provides an overview of weed hybridization and its management implications. We describe intrinsic and extrinsic factors that influence hybrid fitness in agroecosystems. We also survey the rapidly growing literature on crop-weed hybridization and the link between hybridization and invasiveness. These topics are increasingly relevant in this era of genetic tools for crop improvement, intensive and simplified cropping systems, and globalized trade. The review concludes with suggested research priorities, including hybridization in the context of climate change, plant-insect interactions, and redesigned weed management programs. From a weed management perspective, hybridization is one of many reasons that researchers and land managers must diversify their weed control toolkits.
Collapse
Affiliation(s)
- Anna S Westbrook
- Section of Soil and Crop Sciences, School of Integrative Plant Science, Cornell University, Ithaca, NY, 14853, USA
| | - Antonio DiTommaso
- Section of Soil and Crop Sciences, School of Integrative Plant Science, Cornell University, Ithaca, NY, 14853, USA
| |
Collapse
|
2
|
Vercellino RB, Hernández F, Presotto A. The role of intraspecific crop-weed hybridization in the evolution of weediness and invasiveness: Cultivated and weedy radish (Raphanus sativus) as a case study. AMERICAN JOURNAL OF BOTANY 2023; 110:e16217. [PMID: 37659092 DOI: 10.1002/ajb2.16217] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/26/2023] [Revised: 05/26/2023] [Accepted: 05/30/2023] [Indexed: 09/04/2023]
Abstract
PREMISE The phenotype of hybrids between a crop and its wild or weed counterpart is usually intermediate and maladapted compared to that of their parents; however, hybridization has sometimes been associated with increased fitness, potentially leading to enhanced weediness and invasiveness. Since the ecological context and maternal genetic effects may affect hybrid fitness, they could influence the evolutionary outcomes of hybridization. Here, we evaluated the performance of first-generation crop-weed hybrids of Raphanus sativus and their parents in two contrasting ecological conditions. METHODS Using experimental hybridization and outdoor common garden experiments, we assessed differences in time to flowering, survival to maturity, plant biomass, and reproductive components between bidirectional crop-weed hybrids and their parents in agrestal (wheat cultivation, fertilization, weeding) and ruderal (human-disturbed, uncultivated area) conditions over 2 years. RESULTS Crop, weeds, and bidirectional hybrids overlapped at least partially during the flowering period, indicating a high probability of gene flow. Hybrids survived to maturity at rates at least as successful as their parents and had higher plant biomass and fecundity, which resulted in higher fitness compared to their parents in both environments, without any differences associated with the direction of the hybridization. CONCLUSIONS Intraspecific crop-weed hybridization, regardless of the cross direction, has the potential to promote weediness in weedy R. sativus in agrestal and ruderal environments, increasing the chances for introgression of crop alleles into weed populations. This is the first report of intraspecific crop-weed hybridization in R. sativus.
Collapse
Affiliation(s)
- Román B Vercellino
- Departamento de Agronomía, CERZOS, Universidad Nacional del Sur (UNS)-CONICET, San Andrés 800, Bahía Blanca, 8000, Argentina
| | - Fernando Hernández
- Departamento de Agronomía, CERZOS, Universidad Nacional del Sur (UNS)-CONICET, San Andrés 800, Bahía Blanca, 8000, Argentina
- Department of Zoology and Biodiversity Research Centre, University of British Columbia, Vancouver, British Columbia, Canada
| | - Alejandro Presotto
- Departamento de Agronomía, CERZOS, Universidad Nacional del Sur (UNS)-CONICET, San Andrés 800, Bahía Blanca, 8000, Argentina
| |
Collapse
|
3
|
Alexandre NM, Haji D, Bakhtiari M, Chatla K, Aguilar JM, Arzumanova K, Whiteman NK. A Reference Genome Assembly of Hybrid-Derived California Wild Radish (Raphanus sativus × raphanistrum). J Hered 2022; 113:197-204. [PMID: 35575080 PMCID: PMC9113464 DOI: 10.1093/jhered/esab076] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2021] [Accepted: 11/24/2021] [Indexed: 01/30/2023] Open
Abstract
For agriculturally important plants, pollination and herbivory are 2 ecological factors that play into the success of crop yields. Each is also important in natural environments where invasive plants and their effect on species interactions may alter the native ecology. The California Wild Radish (Raphanus sativus × raphanistrum), a hybrid derived from an agriculturally important crop and a nonnative cultivar, is common in California. Remarkably, it has recently replaced wild populations of both progenitor species. Experiments on phenotypic variation for petal color and antiherbivore defenses suggest both pairs of polymorphisms are maintained as a result of pollinator- and herbivore-mediated natural selection. This species provides an opportunity to understand how natural selection shapes the evolution of ecologically important traits when traits are constrained by 2 opposing forces. Here we provide the genome assembly of the California Wild Radish displaying improvement to currently existing genomes for agronomically important crucifers. This genome sequence provides the tools to dissect the genomic architecture of traits related to herbivory and pollination using natural variation in the wild as well as the ability to infer demographic and selective history in the context of hybridization. Study systems like these will improve our understanding and predictions of evolutionary change for correlated traits.
Collapse
Affiliation(s)
- Nicolas M Alexandre
- Department of Integrative Biology, University of California, Berkeley, Berkeley, CA, USA
| | - Diler Haji
- Department of Integrative Biology, University of California, Berkeley, Berkeley, CA, USA
| | - Moe Bakhtiari
- Department of Integrative Biology, University of California, Berkeley, Berkeley, CA, USA
| | - Kamalakar Chatla
- Department of Integrative Biology, University of California, Berkeley, Berkeley, CA, USA
| | - Jessica M Aguilar
- Department of Integrative Biology, University of California, Berkeley, Berkeley, CA, USA
| | - Ksenia Arzumanova
- Department of Integrative Biology, University of California, Berkeley, Berkeley, CA, USA
| | - Noah K Whiteman
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA, USA
| |
Collapse
|
4
|
Shukla K, Laursen AE, Benavides J, Ejbari N, Campbell LG. Growth and fecundity of colonizing hybrid Raphanus populations are environmentally dependent. AMERICAN JOURNAL OF BOTANY 2021; 108:580-597. [PMID: 33855711 DOI: 10.1002/ajb2.1640] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/14/2020] [Accepted: 12/09/2020] [Indexed: 06/12/2023]
Abstract
PREMISE Hybrid gene pools harbor more genetic variation than progenitor populations. Thus, we expect hybrid populations to exhibit more dynamic evolutionary responses to environmental variation. We ask how environmental variation experienced by adapted and transplanted populations influence the success of late-generation hybrid populations during invasion. METHODS For four generations, 20 wild (Raphanus raphanistrum) and 20 hybrid radish (R. sativus × R. raphanistrum) plant populations evolved under experimentally manipulated moisture conditions (dry, wet, control-sheltered, or control-unsheltered plots; i.e., evolutionary environment) in old fields near Toronto, Canada. We planted advanced-generation wild and hybrid radishes in sheltered plots and exposed them to either an evolutionary or a novel watering environment. To determine how soil moisture would influence invasion success, we compared the phenotype and fecundity of plants grown in these various environments. RESULTS Hybridization produced larger plants. In wet environments, hybrid seedlings emerged more frequently and expressed higher photosynthetic activity. Low-moisture, novel conditions delayed and reduced seedling emergence frequency. Hybrid plants and those that evolved under relatively wet environments exhibited higher aboveground biomass. Hybrid plants from control-sheltered plots colonizing novel moisture environments were more fecund than comparable wild plants. CONCLUSIONS Dry environments are less likely than other evolutionary environments to contribute colonists. However, relatively wet locations support the evolution of relatively fecund plants, especially crop-wild hybrid populations. Thus, our results provide a strong mechanistic explanation for variation in the relative success of crop-wild hybrids among study locations and a new standard for studies that assess the risk of crop-wild hybridization events.
Collapse
Affiliation(s)
- Kruti Shukla
- Department of Chemistry and Biology, Ryerson University, Toronto, Ontario, M5B 2K3, Canada
| | - Andrew E Laursen
- Department of Chemistry and Biology, Ryerson University, Toronto, Ontario, M5B 2K3, Canada
| | - Jessica Benavides
- Department of Chemistry and Biology, Ryerson University, Toronto, Ontario, M5B 2K3, Canada
| | - Neda Ejbari
- Department of Chemistry and Biology, Ryerson University, Toronto, Ontario, M5B 2K3, Canada
| | - Lesley G Campbell
- Department of Chemistry and Biology, Ryerson University, Toronto, Ontario, M5B 2K3, Canada
| |
Collapse
|
5
|
Gering E, Incorvaia D, Henriksen R, Conner J, Getty T, Wright D. Getting Back to Nature: Feralization in Animals and Plants. Trends Ecol Evol 2019; 34:1137-1151. [PMID: 31488326 PMCID: PMC7479514 DOI: 10.1016/j.tree.2019.07.018] [Citation(s) in RCA: 40] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2019] [Revised: 07/23/2019] [Accepted: 07/25/2019] [Indexed: 11/24/2022]
Abstract
Formerly domesticated organisms and artificially selected genes often escape controlled cultivation, but their subsequent evolution is not well studied. In this review, we examine plant and animal feralization through an evolutionary lens, including how natural selection, artificial selection, and gene flow shape feral genomes, traits, and fitness. Available evidence shows that feralization is not a mere reversal of domestication. Instead, it is shaped by the varied and complex histories of feral populations, and by novel selection pressures. To stimulate further insight we outline several future directions. These include testing how 'domestication genes' act in wild settings, studying the brains and behaviors of feral animals, and comparative analyses of feral populations and taxa. This work offers feasible and exciting research opportunities with both theoretical and practical applications.
Collapse
Affiliation(s)
- Eben Gering
- Department of Integrative Biology and Ecology, Evolutionary Biology, and Behavior Program, Michigan State University, East Lansing, MI, USA; Department of Biological Sciences, Halmos College of Natural Sciences and Oceanography, Nova Southeastern University, Davie, FL, USA.
| | - Darren Incorvaia
- Department of Integrative Biology and Ecology, Evolutionary Biology, and Behavior Program, Michigan State University, East Lansing, MI, USA
| | - Rie Henriksen
- IIFM Biology and AVIAN Behavioural Genomics and Physiology Group, Linköping University, Linköping, Sweden
| | - Jeffrey Conner
- Department of Integrative Biology and Ecology, Evolutionary Biology, and Behavior Program, Michigan State University, East Lansing, MI, USA; Kellogg Biological Station and Dept. of Plant Biology, Michigan State University, Hickory Corners, MI, USA
| | - Thomas Getty
- Department of Integrative Biology and Ecology, Evolutionary Biology, and Behavior Program, Michigan State University, East Lansing, MI, USA
| | - Dominic Wright
- IIFM Biology and AVIAN Behavioural Genomics and Physiology Group, Linköping University, Linköping, Sweden
| |
Collapse
|
6
|
Williams J, Lambert AM, Long R, Saltonstall K. Does hybrid Phragmites australis differ from native and introduced lineages in reproductive, genetic, and morphological traits? AMERICAN JOURNAL OF BOTANY 2019; 106:29-41. [PMID: 30633812 DOI: 10.1002/ajb2.1217] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/06/2018] [Accepted: 10/03/2018] [Indexed: 06/09/2023]
Abstract
PREMISE OF THE STUDY Hybridization between previously isolated species or lineages can stimulate invasiveness because of increased genetic diversity and inherited traits facilitating competitive and reproductive potential. We evaluated differences in stand characteristics and sexual and vegetative reproduction among native, introduced, and hybrid Phragmites australis lineages in the southwestern United States. We also assessed the degree of hybridization among lineages and backcrossing of hybrids with parental lineages. METHODS Growth and morphological characteristics were measured in native, introduced, and hybrid Phragmites stands to evaluate relative cover and dominance in associated plant communities. Panicles were collected from stands to evaluate germination, dormancy, and differences in seed traits. Seedlings from germination trials were genotyped to determine frequency of crossing and backcrossing among lineages. KEY RESULTS Introduced and hybrid Phragmites stands had significantly greater stem and panicle densities than native stands and were more likely to be dominant members of their respective plant communities. Hybrid seed outputs were significantly greater, but hybrid seeds had lower germination rates than those from native and introduced lineages. We detected a novel hybridization event between native and introduced lineages, but found no strong evidence of hybrids backcrossing with parental lineages. CONCLUSIONS Hybrid Phragmites in the Southwest exhibits reproductive, genetic, and morphological characteristics from both parental lineages that facilitate dispersal, establishment, and aggressive growth, including high reproductive output, rhizome viability, and aboveground biomass, with smaller seeds and greater genetic diversity than its progenitors. Our results show hybrids can inherit traits that confer invasiveness and provide insight for managing this species complex and other cryptic species with native and introduced variants with potential for intraspecific hybridization.
Collapse
Affiliation(s)
- Jared Williams
- Marine Science Institute and Cheadle Center for Biodiversity and Ecological Restoration, University of California, Santa Barbara, CA, 93106-6150, USA
| | - Adam M Lambert
- Marine Science Institute and Cheadle Center for Biodiversity and Ecological Restoration, University of California, Santa Barbara, CA, 93106-6150, USA
| | - Randy Long
- Ecology, Evolution, and Marine Biology, University of California, Santa Barbara, CA, 93106, USA
| | - Kristin Saltonstall
- Smithsonian Tropical Research Institute, Apartado, 0843-03092, Balboa, Ancon, Republic of Panama
| |
Collapse
|
7
|
Charbonneau A, Tack D, Lale A, Goldston J, Caple M, Conner E, Barazani O, Ziffer-Berger J, Dworkin I, Conner JK. Weed evolution: Genetic differentiation among wild, weedy, and crop radish. Evol Appl 2018; 11:1964-1974. [PMID: 30459841 PMCID: PMC6231464 DOI: 10.1111/eva.12699] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2017] [Revised: 07/21/2018] [Accepted: 08/06/2018] [Indexed: 11/30/2022] Open
Abstract
Approximately 200 weed species are responsible for more than 90% of crop losses and these comprise less than one percent of all named plant species, suggesting that there are only a few evolutionary routes that lead to weediness. Agricultural weeds can evolve along three main paths: they can be escaped crops, wild species, or crop‐wild hybrids. We tested these three hypotheses in weedy radish, a weed of small grains and an emerging model for investigating the evolution of agricultural weeds, using 21 CAPS and SSR markers scored on 338 individuals from 34 populations representing all major species and sub‐species in the radish genus Raphanus. To test for adaptation of the weeds to the agricultural environment, we estimated genetic differentiation in flowering time in a series of common garden experiments with over 2,400 individuals from 43 populations (all but one of the genotyped populations plus 10 additional populations). Our findings suggest that the agricultural weed radish R. r. raphanistrum is most genetically similar to native populations of R. r. raphanistrum and is likely not a feral crop or crop hybrid. We also show that weedy radish flowers more rapidly than any other Raphanus population or cultivar, which is consistent with rapid adaptation to the frequent and severe disturbance that characterizes agricultural fields.
Collapse
Affiliation(s)
| | - David Tack
- Department of Biology Pennsylvania State University University Park Pennsylvania
| | - Allison Lale
- Kellogg Biological Station and Department of Plant Biology Michigan State University Hickory Corners Michigan
| | - Josh Goldston
- Rosenstiel School of Marine and Atmospheric Science Miami Florida
| | - Mackenzie Caple
- Kellogg Biological Station and Department of Plant Biology Michigan State University Hickory Corners Michigan
| | - Emma Conner
- Kellogg Biological Station and Department of Plant Biology Michigan State University Hickory Corners Michigan
| | | | | | - Ian Dworkin
- Department of Biology McMaster University Hamilton Ontario Canada
| | - Jeffrey K Conner
- Kellogg Biological Station and Department of Plant Biology Michigan State University Hickory Corners Michigan
| |
Collapse
|
8
|
Meffin R, Duncan RP, Hulme PE. Testing weed risk assessment paradigms: Intraspecific differences in performance and naturalisation risk outweigh interspecific differences in alien
Brassica. J Appl Ecol 2018. [DOI: 10.1111/1365-2664.12993] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Affiliation(s)
- Ross Meffin
- Biosecurity SA Primary Industries and Regions South Australia Adelaide SA Australia
| | - Richard P. Duncan
- Institute for Applied Ecology University of Canberra Canberra ACT Australia
| | - Philip E. Hulme
- Bio‐Protection Research Centre Lincoln University Lincoln New Zealand
| |
Collapse
|
9
|
Introgressive replacement of natives by invading Arion pest slugs. Sci Rep 2017; 7:14908. [PMID: 29097725 PMCID: PMC5668256 DOI: 10.1038/s41598-017-14619-y] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2017] [Accepted: 10/09/2017] [Indexed: 11/09/2022] Open
Abstract
Hybridization with invasive species is one of the major threats to the phenotypic and genetic persistence of native organisms worldwide. Arion vulgaris (syn. lusitanicus) is a major agricultural pest slug that successfully invaded many European countries in recent decades, but its impact on closely related native species remains unclear. Here, we hypothesized that the regional decline of native A. rufus is connected with the spread of invasive A. vulgaris, and tested whether this can be linked to hybridization between the two species by analyzing 625 Arion sp. along altitudinal transects in three regions in Switzerland. In each region, we observed clear evidence of different degrees of genetic admixture, suggesting recurrent hybridization beyond the first generation. We found spatial differences in admixture patterns that might reflect distinct invasion histories among the regions. Our analyses provide a landscape level perspective for the genetic interactions between invasive and native animals during the invasion. We predict that without specific management action, A. vulgaris will further expand its range, which might lead to local extinction of A. rufus and other native slugs in the near future. Similar processes are likely occurring in other regions currently invaded by A. vulgaris.
Collapse
|
10
|
Hybridization rate and genotypic diversity of apomictic hybrids between native (Taraxacum japonicum) and introduced (T. officinale) dandelions in western Japan. CONSERV GENET 2017. [DOI: 10.1007/s10592-017-1014-y] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
|
11
|
Teitel Z, Klimowski A, Campbell LG. Assessing the effects of hybridization and precipitation on invasive weed demography using strength of selection on vital rates. BMC Evol Biol 2016; 16:266. [PMID: 27923349 PMCID: PMC5142176 DOI: 10.1186/s12862-016-0833-7] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2016] [Accepted: 11/20/2016] [Indexed: 11/10/2022] Open
Abstract
Background As global climate change transforms average temperature and rainfall, species distributions may meet, increasing the potential for hybridization and altering individual fitness and population growth. Altered rainfall specifically may shift the strength and direction of selection, also manipulating population trajectories. Here, we investigated the role of interspecific hybridization and selection imposed by rainfall on the evolution of weedy life-history in non-hybrid (Raphanus raphanistrum) and hybrid (R. raphanistrum x R. sativus) populations using a life table response experiment. Results In documenting long-term population dynamics, we determined intrinsic (r) and asymptotic (λ) population growth rates and sensitivities, a measure of selection imposed on demographic rates. Hybrid populations experienced 8.7-10.3 times stronger selection than wild populations for increased seedling survival. Whereas crop populations generally exhibit little dormancy and wild populations often exhibit dormancy, non-hybrid populations experienced 10% stronger selection than hybrid populations for exhibiting seed dormancy. Selection on survival-to-flowering in wild, not hybrid, populations declined marginally with increasing soil moisture. Hybrid populations exhibited greater r, but not λ, than wild populations regardless of moisture environment. In general, fecundity contributed most to differences in λ but fecundity only contributed positively to hybrid λ relative to wild λ when precipitation was altered (either higher or lower than control) and not under control watering conditions. Conclusions Selection on key demographic traits may not change dramatically in response to rainfall, and hybridization may more strongly influence the demography of these weedy species than rainfall. If hybrid populations can respond to selection for increased dormancy, this may make it more difficult to deplete weed seed banks and increase the persistence of crop genes in weed populations.
Collapse
Affiliation(s)
- Zachary Teitel
- Department of Chemistry and Biology, Ryerson University, 350 Victoria Street, Toronto, ON, M5B 2K3, Canada.,Current Address: Department of Integrative Biology, University of Guelph, 50 Stone Road East, Guelph, ON, N1G 2W1, Canada
| | - Agnieszka Klimowski
- Department of Chemistry and Biology, Ryerson University, 350 Victoria Street, Toronto, ON, M5B 2K3, Canada.,Current Address: Department of Physical and Environmental Sciences, University of Toronto Scarborough, 1265 Military Trail, Toronto, ON, M1C 1A4, Canada
| | - Lesley G Campbell
- Department of Chemistry and Biology, Ryerson University, 350 Victoria Street, Toronto, ON, M5B 2K3, Canada.
| |
Collapse
|
12
|
Kanapeckas KL, Vigueira CC, Ortiz A, Gettler KA, Burgos NR, Fischer AJ, Lawton-Rauh AL. Escape to Ferality: The Endoferal Origin of Weedy Rice from Crop Rice through De-Domestication. PLoS One 2016; 11:e0162676. [PMID: 27661982 PMCID: PMC5035073 DOI: 10.1371/journal.pone.0162676] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2015] [Accepted: 08/26/2016] [Indexed: 11/30/2022] Open
Abstract
Domestication is the hallmark of evolution and civilization and harnesses biodiversity through selection for specific traits. In regions where domesticated lines are grown near wild relatives, congeneric sources of aggressive weedy genotypes cause major economic losses. Thus, the origins of weedy genotypes where no congeneric species occur raise questions regarding management effectiveness and evolutionary mechanisms responsible for weedy population success. Since eradication in the 1970s, California growers avoided weedy rice through continuous flood culture and zero-tolerance guidelines, preventing the import, presence, and movement of weedy seeds. In 2003, after decades of no reported presence in California, a weedy rice population was confirmed in dry-seeded fields. Our objectives were to identify the origins and establishment of this population and pinpoint possible phenotypes involved. We show that California weedy rice is derived from a different genetic source among a broad range of AA genome Oryzas and is most recently diverged from O. sativa temperate japonica cultivated in California. In contrast, other weedy rice ecotypes in North America (Southern US) originate from weedy genotypes from China near wild Oryza, and are derived through existing crop-wild relative crosses. Analyses of morphological data show that California weedy rice subgroups have phenotypes like medium-grain or gourmet cultivars, but have colored pericarp, seed shattering, and awns like wild relatives, suggesting that reversion to non-domestic or wild-like traits can occur following domestication, despite apparent fixation of domestication alleles. Additionally, these results indicate that preventive methods focused on incoming weed sources through contamination may miss burgeoning weedy genotypes that rapidly adapt, establish, and proliferate. Investigating the common and unique evolutionary mechanisms underlying global weed origins and subsequent interactions with crop relatives sheds light on how weeds evolve and addresses broader questions regarding the stability of selection during domestication and crop improvement.
Collapse
Affiliation(s)
- Kimberly L. Kanapeckas
- Department of Genetics and Biochemistry, Clemson University, Clemson, South Carolina, United States of America
- South Carolina Department of Natural Resources, Marine Resources Research Institute, Charleston, South Carolina, United States of America
| | - Cynthia C. Vigueira
- Department of Genetics and Biochemistry, Clemson University, Clemson, South Carolina, United States of America
- Department of Biology, High Point University, High Point, North Carolina, United States of America
| | - Aida Ortiz
- Department of Plant Sciences, University of California Davis, Davis, California, United States of America
| | - Kyle A. Gettler
- Department of Genetics and Biochemistry, Clemson University, Clemson, South Carolina, United States of America
| | - Nilda R. Burgos
- Department of Crop, Soil, and Environmental Sciences, University of Arkansas, Fayetteville, Arkansas, United States of America
| | - Albert J. Fischer
- Department of Plant Sciences, University of California Davis, Davis, California, United States of America
| | - Amy L. Lawton-Rauh
- Department of Genetics and Biochemistry, Clemson University, Clemson, South Carolina, United States of America
| |
Collapse
|
13
|
Hooftman DAP, Bullock JM, Morley K, Lamb C, Hodgson DJ, Bell P, Thomas J, Hails RS. Seed bank dynamics govern persistence of Brassica hybrids in crop and natural habitats. ANNALS OF BOTANY 2015; 115:147-157. [PMID: 25452253 PMCID: PMC4284111 DOI: 10.1093/aob/mcu213] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/14/2014] [Revised: 08/26/2014] [Accepted: 09/16/2014] [Indexed: 06/04/2023]
Abstract
BACKGROUND AND AIMS Gene flow from crops to their wild relatives has the potential to alter population growth rates and demography of hybrid populations, especially when a new crop has been genetically modified (GM). This study introduces a comprehensive approach to assess this potential for altered population fitness, and uses a combination of demographic data in two habitat types and mathematical (matrix) models that include crop rotations and outcrossing between parental species. METHODS Full life-cycle demographic rates, including seed bank survival, of non-GM Brassica rapa × B. napus F1 hybrids and their parent species were estimated from experiments in both agricultural and semi-natural habitats. Altered fitness potential was modelled using periodic matrices including crop rotations and outcrossing between parent species. KEY RESULTS The demographic vital rates (i.e. for major stage transitions) of the hybrid population were intermediate between or lower than both parental species. The population growth rate (λ) of hybrids indicated decreases in both habitat types, and in a semi-natural habitat hybrids became extinct at two sites. Elasticity analyses indicated that seed bank survival was the greatest contributor to λ. In agricultural habitats, hybrid populations were projected to decline, but with persistence times up to 20 years. The seed bank survival rate was the main driver determining persistence. It was found that λ of the hybrids was largely determined by parental seed bank survival and subsequent replenishment of the hybrid population through outcrossing of B. rapa with B. napus. CONCLUSIONS Hybrid persistence was found to be highly dependent on the seed bank, suggesting that targeting hybrid seed survival could be an important management option in controlling hybrid persistence. For local risk mitigation, an increased focus on the wild parent is suggested. Management actions, such as control of B. rapa, could indirectly reduce hybrid populations by blocking hybrid replenishment.
Collapse
Affiliation(s)
- Danny A P Hooftman
- Centre for Ecology and Hydrology, Benson Lane, Wallingford OX10 8BB, UK, School of Biosciences, University of Exeter, Cornwall Campus, Penryn TR10 9EZ, UK and National Institute of Agricultural Botany, Huntingdon Rd, Cambridge CB3 0EL, UK
| | - James M Bullock
- Centre for Ecology and Hydrology, Benson Lane, Wallingford OX10 8BB, UK, School of Biosciences, University of Exeter, Cornwall Campus, Penryn TR10 9EZ, UK and National Institute of Agricultural Botany, Huntingdon Rd, Cambridge CB3 0EL, UK
| | - Kathryn Morley
- Centre for Ecology and Hydrology, Benson Lane, Wallingford OX10 8BB, UK, School of Biosciences, University of Exeter, Cornwall Campus, Penryn TR10 9EZ, UK and National Institute of Agricultural Botany, Huntingdon Rd, Cambridge CB3 0EL, UK
| | - Caroline Lamb
- Centre for Ecology and Hydrology, Benson Lane, Wallingford OX10 8BB, UK, School of Biosciences, University of Exeter, Cornwall Campus, Penryn TR10 9EZ, UK and National Institute of Agricultural Botany, Huntingdon Rd, Cambridge CB3 0EL, UK
| | - David J Hodgson
- Centre for Ecology and Hydrology, Benson Lane, Wallingford OX10 8BB, UK, School of Biosciences, University of Exeter, Cornwall Campus, Penryn TR10 9EZ, UK and National Institute of Agricultural Botany, Huntingdon Rd, Cambridge CB3 0EL, UK
| | - Philippa Bell
- Centre for Ecology and Hydrology, Benson Lane, Wallingford OX10 8BB, UK, School of Biosciences, University of Exeter, Cornwall Campus, Penryn TR10 9EZ, UK and National Institute of Agricultural Botany, Huntingdon Rd, Cambridge CB3 0EL, UK
| | - Jane Thomas
- Centre for Ecology and Hydrology, Benson Lane, Wallingford OX10 8BB, UK, School of Biosciences, University of Exeter, Cornwall Campus, Penryn TR10 9EZ, UK and National Institute of Agricultural Botany, Huntingdon Rd, Cambridge CB3 0EL, UK
| | - Rosemary S Hails
- Centre for Ecology and Hydrology, Benson Lane, Wallingford OX10 8BB, UK, School of Biosciences, University of Exeter, Cornwall Campus, Penryn TR10 9EZ, UK and National Institute of Agricultural Botany, Huntingdon Rd, Cambridge CB3 0EL, UK
| |
Collapse
|
14
|
Genetic differentiation and phenotypic plasticity in life-history traits between native and introduced populations of invasive maple trees. Biol Invasions 2014. [DOI: 10.1007/s10530-014-0781-3] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
|
15
|
Hovick SM, Whitney KD. Hybridisation is associated with increased fecundity and size in invasive taxa: meta-analytic support for the hybridisation-invasion hypothesis. Ecol Lett 2014; 17:1464-77. [PMID: 25234578 PMCID: PMC4231983 DOI: 10.1111/ele.12355] [Citation(s) in RCA: 78] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2014] [Revised: 06/11/2014] [Accepted: 08/14/2014] [Indexed: 02/04/2023]
Abstract
The hypothesis that interspecific hybridisation promotes invasiveness has received much recent
attention, but tests of the hypothesis can suffer from important limitations. Here, we provide the
first systematic review of studies experimentally testing the hybridisation-invasion (H-I)
hypothesis in plants, animals and fungi. We identified 72 hybrid systems for which hybridisation has
been putatively associated with invasiveness, weediness or range expansion. Within this group, 15
systems (comprising 34 studies) experimentally tested performance of hybrids vs. their parental
species and met our other criteria. Both phylogenetic and non-phylogenetic meta-analyses
demonstrated that wild hybrids were significantly more fecund and larger than their parental taxa,
but did not differ in survival. Resynthesised hybrids (which typically represent earlier generations
than do wild hybrids) did not consistently differ from parental species in fecundity, survival or
size. Using meta-regression, we found that fecundity increased (but survival decreased) with
generation in resynthesised hybrids, suggesting that natural selection can play an important role in
shaping hybrid performance – and thus invasiveness – over time. We conclude that the
available evidence supports the H-I hypothesis, with the caveat that our results are clearly driven
by tests in plants, which are more numerous than tests in animals and fungi.
Collapse
Affiliation(s)
- Stephen M Hovick
- Department of Evolution, Ecology, and Organismal Biology, The Ohio State University, Columbus, OH, 43210, USA
| | | |
Collapse
|
16
|
Guo Q. Plant hybridization: the role of human disturbance and biological invasion. DIVERS DISTRIB 2014. [DOI: 10.1111/ddi.12245] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Affiliation(s)
- Qinfeng Guo
- USDA FS; Eastern Forest Environmental Threat Assessment Center; 200 WT Weaver Blvd. Asheville NC 28804 USA
| |
Collapse
|
17
|
Pierson JC, Swain SM, Young AG. Incest versus abstinence: reproductive trade-offs between mate limitation and progeny fitness in a self-incompatible invasive plant. Ecol Evol 2013; 3:5066-75. [PMID: 24455137 PMCID: PMC3892369 DOI: 10.1002/ece3.875] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2013] [Revised: 10/08/2013] [Accepted: 10/10/2013] [Indexed: 11/20/2022] Open
Abstract
Plant mating systems represent an evolutionary and ecological trade-off between reproductive assurance through selfing and maximizing progeny fitness through outbreeding. However, many plants with sporophytic self-incompatibility systems exhibit dominance interactions at the S-locus that allow biparental inbreeding, thereby facilitating mating between individuals that share alleles at the S-locus. We investigated this trade-off by estimating mate availability and biparental inbreeding depression in wild radish from five different populations across Australia. We found dominance interactions among S-alleles increased mate availability relative to estimates based on individuals that did not share S-alleles. Twelve of the sixteen fitness variables were significantly reduced by inbreeding. For all the three life-history phases evaluated, self-fertilized offspring suffered a greater than 50% reduction in fitness, while full-sib and half-sib offspring suffered a less than 50% reduction in fitness. Theory indicates that fitness costs greater than 50% can result in an evolutionary trajectory toward a stable state of self-incompatibility (SI). This study suggests that dominance interactions at the S-locus provide a possible third stable state between SI and SC where biparental inbreeding increases mate availability with relatively minor fitness costs. This strategy allows weeds to establish in new environments while maintaining a functional SI system.
Collapse
Affiliation(s)
| | - Stephen M Swain
- CSIRO Plant Industry GPO Box 1600, Canberra, ACT, 2601, Australia
| | - Andrew G Young
- CSIRO Plant Industry GPO Box 1600, Canberra, ACT, 2601, Australia
| |
Collapse
|
18
|
Rollins LA, Moles AT, Lam S, Buitenwerf R, Buswell JM, Brandenburger CR, Flores-Moreno H, Nielsen KB, Couchman E, Brown GS, Thomson FJ, Hemmings F, Frankham R, Sherwin WB. High genetic diversity is not essential for successful introduction. Ecol Evol 2013; 3:4501-17. [PMID: 24340190 PMCID: PMC3856749 DOI: 10.1002/ece3.824] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2013] [Revised: 08/16/2013] [Accepted: 08/28/2013] [Indexed: 01/08/2023] Open
Abstract
Some introduced populations thrive and evolve despite the presumed loss of diversity at introduction. We aimed to quantify the amount of genetic diversity retained at introduction in species that have shown evidence of adaptation to their introduced environments. Samples were taken from native and introduced ranges of Arctotheca populifolia and Petrorhagia nanteuilii. Using microsatellite data, we identified the source for each introduction, estimated genetic diversity in native and introduced populations, and calculated the amount of diversity retained in introduced populations. These values were compared to those from a literature review of diversity in native, confamilial populations and to estimates of genetic diversity retained at introduction. Gene diversity in the native range of both species was significantly lower than for confamilials. We found that, on average, introduced populations showing evidence of adaptation to their new environments retained 81% of the genetic diversity from the native range. Introduced populations of P. nanteuilii had higher genetic diversity than found in the native source populations, whereas introduced populations of A. populifolia retained only 14% of its native diversity in one introduction and 1% in another. Our literature review has shown that most introductions demonstrating adaptive ability have lost diversity upon introduction. The two species studied here had exceptionally low native range genetic diversity. Further, the two introductions of A. populifolia represent the largest percentage loss of genetic diversity in a species showing evidence of substantial morphological change in the introduced range. While high genetic diversity may increase the likelihood of invasion success, the species examined here adapted to their new environments with very little neutral genetic diversity. This finding suggests that even introductions founded by small numbers of individuals have the potential to become invasive.
Collapse
Affiliation(s)
- Lee A Rollins
- School of Life & Environmental Sciences, Centre for Integrative Ecology, Deakin University Geelong, Vic., 3216, Australia ; School of Biological, Earth and Environmental Sciences, Evolution & Ecology Research Centre, University of New South Wales Sydney, NSW, 2052, Australia
| | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
19
|
Pearse IS, Bastow JL, Tsang A. Radish introduction affects soil biota and has a positive impact on the growth of a native plant. Oecologia 2013; 174:471-8. [PMID: 24072439 DOI: 10.1007/s00442-013-2779-4] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2013] [Accepted: 09/07/2013] [Indexed: 10/26/2022]
Abstract
Introduced plants may out-compete natives by belowground allelopathic effects on soil communities including the symbionts of native plants. We tested for an allelopathic effect of an introduced crucifer, Raphanus sativus, on a common neighboring legume, Lupinus nanus, on the legume's rhizobium affiliates, and on the broader soil community. In both field observations and a greenhouse experiment, we found that R. sativus decreased the density of nodules on L. nanus roots. However, in the greenhouse experiment, R. sativus soils only decreased the density of small, likely non-beneficial rhizobium nodules. In the same experiment, R. sativus soils decreased fungivorous nematode abundance, though there was no effect of R. sativus introduction on fungal density. In the greenhouse experiment, R. sativus soils had a net positive effect on L. nanus biomass. One explanation of this effect is that R. sativus introduction might alter the mutualistic/parasitic relationship between L. nanus and its rhizobial associates with a net benefit to L. nanus. Our results suggest that introduced brassicas can quickly alter belowground communities, but that the net effect of this on neighboring plants is not necessarily negative.
Collapse
Affiliation(s)
- Ian S Pearse
- Department of Entomology, University of California, Davis, Davis, CA, 95616, USA,
| | | | | |
Collapse
|
20
|
Standing variation boosted by multiple sources of introduction contributes to the success of the introduced species, Lotus corniculatus. Biol Invasions 2013. [DOI: 10.1007/s10530-013-0488-x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
|
21
|
Zelikova TJ, Hufbauer RA, Reed SC, Wertin T, Fettig C, Belnap J. Eco-evolutionary responses of Bromus tectorum to climate change: implications for biological invasions. Ecol Evol 2013; 3:1374-87. [PMID: 23762522 PMCID: PMC3678490 DOI: 10.1002/ece3.542] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2013] [Revised: 02/15/2013] [Accepted: 02/26/2013] [Indexed: 11/23/2022] Open
Abstract
How plant populations, communities, and ecosystems respond to climate change is a critical focus in ecology today. The responses of introduced species may be especially rapid. Current models that incorporate temperature and precipitation suggest that future Bromus tectorum invasion risk is low for the Colorado Plateau. With a field warming experiment at two sites in southeastern Utah, we tested this prediction over 4 years, measuring B. tectorum phenology, biomass, and reproduction. In a complimentary greenhouse study, we assessed whether changes in field B. tectorum biomass and reproductive output influence offspring performance. We found that following a wet winter and early spring, the timing of spring growth initiation, flowering, and summer senescence all advanced in warmed plots at both field sites and the shift in phenology was progressively larger with greater warming. Earlier green-up and development was associated with increases in B. tectorum biomass and reproductive output, likely due early spring growth, when soil moisture was not limiting, and a lengthened growing season. Seeds collected from plants grown in warmed plots had higher biomass and germination rates and lower mortality than seeds from ambient plots. However, in the following two dry years, we observed no differences in phenology between warmed and ambient plots. In addition, warming had a generally negative effect on B. tectorum biomass and reproduction in dry years and this negative effect was significant in the plots that received the highest warming treatment. In contrast to models that predict negative responses of B. tectorum to warmer climate on the Colorado Plateau, the effects of warming were more nuanced, relied on background climate, and differed between the two field sites. Our results highlight the importance of considering the interacting effects of temperature, precipitation, and site-specific characteristics such as soil texture, on plant demography and have direct implications for B. tectorum invasion dynamics on the Colorado Plateau.
Collapse
Affiliation(s)
- Tamara J Zelikova
- Southwest Biological Science Center, U.S. Geological Survey Moab, Utah, 84532 ; Botany Department, Berry Biodiversity Conservation Center, University of Wyoming Laramie, Wyoming, 82071
| | | | | | | | | | | |
Collapse
|
22
|
The red queen in the corn: agricultural weeds as models of rapid adaptive evolution. Heredity (Edinb) 2012. [PMID: 23188175 DOI: 10.1038/hdy.2012.104] [Citation(s) in RCA: 86] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
Weeds are among the greatest pests of agriculture, causing billions of dollars in crop losses each year. As crop field management practices have changed over the past 12 000 years, weeds have adapted in turn to evade human removal. This evolutionary change can be startlingly rapid, making weeds an appealing system to study evolutionary processes that occur over short periods of time. An understanding of how weeds originate and adapt is needed for successful management; however, relatively little emphasis has been placed on genetically characterizing these systems. Here, we review the current literature on agricultural weed origins and their mechanisms of adaptation. Where possible, we have included examples that have been genetically well characterized. Evidence for three possible, non-mutually exclusive weed origins (from wild species, crop-wild hybrids or directly from crops) is discussed with respect to what is known about the microevolutionary signatures that result from these processes. We also discuss what is known about the genetic basis of adaptive traits in weeds and the range of genetic mechanisms that are responsible. With a better understanding of genetic mechanisms underlying adaptation in weedy species, we can address the more general process of adaptive evolution and what can be expected as we continue to apply selective pressures in agroecosystems around the world.
Collapse
|
23
|
Shine R. Invasive species as drivers of evolutionary change: cane toads in tropical Australia. Evol Appl 2012; 5:107-16. [PMID: 25568034 PMCID: PMC3353345 DOI: 10.1111/j.1752-4571.2011.00201.x] [Citation(s) in RCA: 61] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2011] [Accepted: 07/20/2011] [Indexed: 12/20/2022] Open
Abstract
The arrival of an invasive species can have wide-ranging ecological impacts on native taxa, inducing rapid evolutionary responses in ways that either reduce the invader's impact or exploit the novel opportunity that it provides. The invasion process itself can cause substantial evolutionary shifts in traits that influence the invader's dispersal rate (via both adaptive and non-adaptive mechanisms) and its ability to establish new populations. I briefly review the nature of evolutionary changes likely to be set in train by a biological invasion, with special emphasis on recent results from my own research group on the invasion of cane toads (Rhinella marina) through tropical Australia. The toads' invasion has caused evolutionary changes both in the toads and in native taxa. Many of those changes are adaptive, but others may result from non-adaptive evolutionary processes: for example, the evolved acceleration in toad dispersal rates may be due to spatial sorting of dispersal-enhancing genes, rather than fitness advantages to faster-dispersing individuals. Managers need to incorporate evolutionary dynamics into their conservation planning, because biological invasions can affect both the rates and the trajectories of evolutionary change.
Collapse
Affiliation(s)
- Richard Shine
- Biological Sciences A08, University of Sydney Sydney, NSW, Australia
| |
Collapse
|
24
|
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.
Collapse
Affiliation(s)
- Stephen M Hovick
- Department of Ecology and Evolutionary Biology, Rice University, Houston, Texas 77005, USA.
| | | | | | | |
Collapse
|
25
|
|
26
|
Erfmeier A, Tsaliki M, Roß CA, Bruelheide H. Genetic and phenotypic differentiation between invasive and native Rhododendron (Ericaceae) taxa and the role of hybridization. Ecol Evol 2011; 1:392-407. [PMID: 22393509 PMCID: PMC3287310 DOI: 10.1002/ece3.38] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2011] [Revised: 08/23/2011] [Accepted: 08/24/2011] [Indexed: 11/30/2022] Open
Abstract
Hybridization has been repeatedly put forward to explain the invasiveness of Rhododendron ponticum L. in the British Isles. The present study investigates the pattern of ecotypic differentiation and hybridization among native North American R. catawbiense and R. maximum, native R. ponticum from Georgia and Spain, and invasive R. ponticum from Ireland and aims to assess the contribution of hybridization for Rhododendron invasion in the British Isles. Six populations per taxon were analyzed with AFLP markers for genetic dissimilarity, subjected to germination and growth experiments, and tested for frost hardiness. We assessed variation in morphological and ecological characteristics to identify traits displaying evidence of hybridization, thus, promoting invasiveness. Molecular marker analyses revealed a clear distinction between North American R. catawbiense and R. maximum on the one hand, and all R. ponticum populations on the other hand, displaying a complete intermixture of native Spanish and invasive Irish populations. Multivariate analyses of traits revealed leaf length-width ratio, relative growth rates (RGRs) in leaf length, root biomass, and shoot-root ratio to significantly discriminate between the different taxa and unequivocally assigned invasive Irish R. ponticum to the Spanish phenotypes. While the Irish R. ponticum had similar growth traits as conspecific native R. ponticum provenances, germination and biomass allocation were more similar to North American R. catawbiense and R. maximum. Hybridization did not contribute to explaining invasiveness of R. ponticum in Ireland. The similarity in germination and biomass allocation of invasive Irish R. ponticum and North American species has evolved independently and can more probably be attributed to an independent shift within the Ponticum cluster in Ireland.
Collapse
Affiliation(s)
- Alexandra Erfmeier
- Institute of Biology/Geobotany and Botanical Garden, Martin Luther University Halle-WittenbergAm Kirchtor 1, D-06108 Halle, Germany
| | - Marina Tsaliki
- Vegetation Ecology and Conservation Biology, Institute of Ecology and Evolutionary Biology, Bremen UniversityLeobener Street, D-28359 Bremen, Germany
| | - Christel A Roß
- Institute of Biology/Geobotany and Botanical Garden, Martin Luther University Halle-WittenbergAm Kirchtor 1, D-06108 Halle, Germany
| | - Helge Bruelheide
- Institute of Biology/Geobotany and Botanical Garden, Martin Luther University Halle-WittenbergAm Kirchtor 1, D-06108 Halle, Germany
| |
Collapse
|
27
|
Blair AC, Blumenthal D, Hufbauer RA. Hybridization and invasion: an experimental test with diffuse knapweed (Centaurea diffusa Lam.). Evol Appl 2011; 5:17-28. [PMID: 25568026 DOI: 10.1111/j.1752-4571.2011.00203.x] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2011] [Accepted: 07/25/2011] [Indexed: 11/29/2022] Open
Abstract
A number of studies have suggested a link between hybridization and invasion. In this study, we experimentally test the potential for hybridization to influence invasion through a greenhouse common garden study. Diffuse knapweed (DK) (Centaurea diffusa Lam.) was introduced to North America with admixture from spotted knapweed (SK) (Centaurea stoebe subsp. stoebe L.). Comparisons between North American DK (including hybrid phenotypes) and native (European) DK in a common garden did not reveal enhanced performance or increased phenotypic variance, suggesting that pre-introduction hybridization or, more generally, post-introduction evolutionary change has not significantly contributed to the invasion of DK. In contrast, early generation hybrids [artificially created Backcross 1 (BC1) plants] exhibited increased variance for eight of the examined traits, and greater leaf and reproductive shoot production when compared to North American DK. Individual BC1 lines differed for several traits, suggesting the importance of the cross for drawing conclusions from such comparisons. When compared to the parental species (DK and SK), the BC1 plants were not transgressive for any of the measured traits. Overall, these findings suggest that if diploid SK is introduced to North America, interspecific hybridization has the potential to result in even more aggressive invaders.
Collapse
Affiliation(s)
- Amy C Blair
- Graduate Degree Program in Ecology and Department of Bioagricultural Sciences and Pest Management, Colorado State University Fort Collins, CO, USA
| | - Dana Blumenthal
- USDA-ARS, Rangeland Resources Research Unit Fort Collins, CO, USA
| | - Ruth A Hufbauer
- Graduate Degree Program in Ecology and Department of Bioagricultural Sciences and Pest Management, Colorado State University Fort Collins, CO, USA
| |
Collapse
|
28
|
Curtis IS. Genetic engineering of radish: current achievements and future goals. PLANT CELL REPORTS 2011; 30:733-744. [PMID: 21191596 DOI: 10.1007/s00299-010-0978-6] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/26/2010] [Revised: 12/06/2010] [Accepted: 12/07/2010] [Indexed: 05/30/2023]
Abstract
Radish is a major root crop grown in the Far East and is especially important to some low-income countries where it is consumed on a daily basis. Developments in gene technology systems have helped to accelerate the production of useful germplasms, but progress has been slow, though achieved, via in planta methods and useful traits have been introduced. In the wake of the new Millennium, future goals in terms of improving transformation efficiency and selection of new traits for generating late-flowering radish are described. Furthermore, the techniques available for incorporating pharmaceutical proteins into radish to deliver edible proteins on-site are discussed. Finally, the concerns of releasing transgenic radish to the field in terms of pollen-mediated gene transfer are also reviewed. Such a report identifies key areas of research that is required to allow the crop satisfy the need of poor impoverished countries in the Far East.
Collapse
MESH Headings
- Adaptation, Physiological
- Crops, Agricultural/genetics
- Crops, Agricultural/growth & development
- Crops, Agricultural/physiology
- Crosses, Genetic
- Asia, Eastern
- Flowers/genetics
- Flowers/growth & development
- Gene Expression Regulation, Plant
- Gene Flow/genetics
- Genes, Plant/genetics
- Genetic Engineering/trends
- Pharmaceutical Preparations
- Plants, Genetically Modified/genetics
- Plants, Genetically Modified/growth & development
- Plants, Genetically Modified/physiology
- Pollen/genetics
- Proteins/genetics
- Proteins/therapeutic use
- Raphanus/genetics
- Raphanus/growth & development
- Raphanus/physiology
- Tissue Culture Techniques/trends
- Transformation, Genetic
- Transgenes/genetics
Collapse
Affiliation(s)
- Ian S Curtis
- Texas AgriLife Research, 2415 E. Hwy 83, Weslaco, TX, 78596, USA.
| |
Collapse
|
29
|
Ellstrand NC, Heredia SM, Leak-Garcia JA, Heraty JM, Burger JC, Yao L, Nohzadeh-Malakshah S, Ridley CE. Crops gone wild: evolution of weeds and invasives from domesticated ancestors. Evol Appl 2010; 3:494-504. [PMID: 25567942 PMCID: PMC3352506 DOI: 10.1111/j.1752-4571.2010.00140.x] [Citation(s) in RCA: 100] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2010] [Accepted: 05/21/2010] [Indexed: 11/26/2022] Open
Abstract
The evolution of problematic plants, both weeds and invasives, is a topic of increasing interest. Plants that have evolved from domesticated ancestors have certain advantages for study. Because of their economic importance, domesticated plants are generally well-characterized and readily available for ecogenetic comparison with their wild descendants. Thus, the evolutionary history of crop descendants has the potential to be reconstructed in some detail. Furthermore, growing crop progenitors with their problematic descendants in a common environment allows for the identification of significant evolutionary differences that correlate with weediness or invasiveness. We sought well-established examples of invasives and weeds for which genetic and/or ethnobotanical evidence has confirmed their evolution from domesticates. We found surprisingly few cases, only 13. We examine our list for generalizations and then some selected cases to reveal how plant pests have evolved from domesticates. Despite their potential utility, crop descendants remain underexploited for evolutionary study. Promising evolutionary research opportunities for these systems are abundant and worthy of pursuit.
Collapse
Affiliation(s)
- Norman C Ellstrand
- Department of Botany & Plant Sciences and Center for Conservation Biology, University of California Riverside, CA, USA
| | - Sylvia M Heredia
- Department of Botany & Plant Sciences and Center for Conservation Biology, University of California Riverside, CA, USA
| | - Janet A Leak-Garcia
- Department of Botany & Plant Sciences and Center for Conservation Biology, University of California Riverside, CA, USA
| | - Joanne M Heraty
- Department of Botany & Plant Sciences and Center for Conservation Biology, University of California Riverside, CA, USA
| | | | - Li Yao
- Department of Botany & Plant Sciences and Center for Conservation Biology, University of California Riverside, CA, USA
| | - Sahar Nohzadeh-Malakshah
- Department of Botany & Plant Sciences and Center for Conservation Biology, University of California Riverside, CA, USA
| | - Caroline E Ridley
- United States Environmental Protection Agency, National Center for Environmental Assessment Arlington, VA, USA
| |
Collapse
|
30
|
Snow AA, Culley TM, Campbell LG, Sweeney PM, Hegde SG, Ellstrand NC. Long-term persistence of crop alleles in weedy populations of wild radish (Raphanus raphanistrum). THE NEW PHYTOLOGIST 2010; 186:537-548. [PMID: 20122132 DOI: 10.1111/j.1469-8137.2009.03172.x] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
*Hybridization allows transgenes and other crop alleles to spread to wild/weedy populations of related taxa. Researchers have debated whether such alleles will persist because low hybrid fitness and linkage to domestication traits could severely impede introgression. *To examine variation in the fates of three unlinked crop alleles, we monitored four experimental, self-seeding, hybrid populations of Raphanus raphanistrum x Raphanus sativus (radish) in Michigan, USA, over a decade. We also compared the fecundity of advanced-generation hybrid plants with wild plants in a common garden experiment. *Initially, F(1) hybrids had reduced fitness, but the populations quickly evolved wild-type pollen fertility. In Year 10, the fecundity of plants from the experimental populations was similar to that of wild genotypes. Crop-specific alleles at the three loci persisted for 10 yr in all populations, and their frequencies varied among loci, populations and years. *This research provides a unique case study of substantial variation in the rates and patterns of crop allele introgression after a single hybridization event. Our findings demonstrate that certain crop alleles can introgress easily while others remain rare, supporting the assumption that neutral or beneficial transgenes that are not linked to maladaptive traits can persist in the wild.
Collapse
Affiliation(s)
- A A Snow
- Department of Evolution, Ecology, and Organismal Biology, Ohio State University, Columbus, OH 43210, USA.
| | | | | | | | | | | |
Collapse
|
31
|
Hooftman DAP, Hartman Y, Oostermeijer JGB, Den Nijs HJCM. Existence of vigorous lineages of crop-wild hybrids in Lettuce under field conditions. ENVIRONMENTAL BIOSAFETY RESEARCH 2009; 8:203-17. [PMID: 20883659 DOI: 10.1051/ebr/2010001] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/13/2010] [Accepted: 06/20/2010] [Indexed: 01/27/2023]
Abstract
Plant to plant gene flow is a route of environmental exposure for GM plants specifically since crosses with wild relatives could lead to the formation of more vigorous hybrids, which could increase the rate of introgression and the environmental impact. Here, we test the first step in the process of potential transgene introgression: whether hybrid vigor can be inherited to the next generation, which could lead to fixation of altered, i.e., elevated, quantitative traits. The potential for a permanent elevated fitness was tested using individual autogamous progeny lineages of hybrids between the crop Lactuca sativa (Lettuce) and the wild species Lactuca serriola (Prickly Lettuce). We compared progeny from motherplants grown under either greenhouse or field conditions. The survival of young plants depended strongly on maternal environment. Furthermore, we observed that offspring reproductive fitness components were correlated with maternal fitness. Our study demonstrates that post-zygotic genotypic sorting at the young plants stage reduces the number of genotypes non-randomly, leading to inheritance of high levels of reproductive traits in the surviving hybrid lineages, compared to the pure wild relatives. Consequently, directional selection could lead to displacement of the pure wild relative and fixation of more vigorous genome segments originating from crops, stabilizing plant traits at elevated levels. Such information can be used to indentify segments which are less likely to introgress into wild relative populations as a target for transgene insertion.
Collapse
Affiliation(s)
- Danny A P Hooftman
- Institute for Biodiversity and Ecosystem Dynamics, University of Amsterdam, The Netherlands.
| | | | | | | |
Collapse
|
32
|
Ridley CE, Ellstrand NC. Rapid evolution of morphology and adaptive life history in the invasive California wild radish (Raphanus sativus) and the implications for management. Evol Appl 2009; 3:64-76. [PMID: 25567904 PMCID: PMC3352453 DOI: 10.1111/j.1752-4571.2009.00099.x] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2009] [Accepted: 08/08/2009] [Indexed: 11/26/2022] Open
Abstract
Understanding the evolution and demography of invasive populations may be key for successful management. In this study, we test whether or not populations of the non-native, hybrid-derived California wild radish have regionally adapted to divergent climates over their 150-year history in California and determine if population demographic dynamics might warrant different region-specific strategies for control. Using a reciprocal transplant approach, we found evidence for genetically based differences both between and among northern, coastal and southern, inland populations of wild radish. Individual fitness was analyzed using a relatively new statistical method called ‘aster modeling’ which integrates temporally sequential fitness measurements. In their respective home environments, fitness differences strongly favored southern populations and only slightly favored northern populations. Demographic rates of transition and sensitivities also differed between regions of origin, suggesting that the most effective approach for reducing overall population growth rate would be to target different life-history stages in each region.
Collapse
Affiliation(s)
- Caroline E Ridley
- Department of Botany and Plant Sciences, University of California Riverside Riverside, CA, USA
| | - Norman C Ellstrand
- Department of Botany and Plant Sciences, University of California Riverside Riverside, CA, USA
| |
Collapse
|