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dc.contributor.supervisor Van Acker, Rene (Plant Science) Gulden, Robert (Plant Science) en
dc.contributor.author Bagavathiannan, Muthukumar
dc.date.accessioned 2010-04-09T15:35:47Z
dc.date.available 2010-04-09T15:35:47Z
dc.date.issued 2010-04-09T15:35:47Z
dc.identifier.uri http://hdl.handle.net/1993/3955
dc.description.abstract Alfalfa is an important forage crop in North America which can also escape cultivation and establish in unmanaged habitats. Genetically modified (GM) alfalfa has been approved for environmental release in Canada and the United States and the occurrence of alfalfa in unmanaged natural and semi-natural habitats may compromise the successful co-existence of GM and non-GM alfalfa. To-date, little information has been available on the nature and dynamics of roadside alfalfa populations and their ability to become feral. Such knowledge is necessary to design efficient trait confinement protocols and to enhance the co-existence of GM and non-GM alfalfa within agricultural regions. The overall aim of this work was to characterize roadside alfalfa populations and to establish their role in novel trait movement. A roadside survey revealed the widespread occurrence of feral alfalfa populations in southern Manitoba. We described the seedbanks of roadside alfalfa populations, seedling recruitment and adult reproductive success, indicating that alfalfa is capable of establishing self-perpetuating feral populations in unmanaged habitats. We also noted the successful establishment of alfalfa in a grass sward representing roadside vegetation. Roadside mowing can reduce (and perhaps prevent) seed production in roadside alfalfa; however, mowing failed to drive the populations to extinction in the short-term. Herbicide (2,4-D) applications controlled alfalfa plants but seeds in the seedbank may still contribute to new seedling recruitment. The roadside alfalfa populations we worked with exhibited high levels of genetic diversity, indicating an absence of past population bottlenecks or genetic drift. In addition, phenotypic characterization provided evidence that roadside alfalfa populations were experiencing selection pressure for adaptive traits including winter survivability, rhizome production and prostrate growth habit; all traits that favor persistence in unmanaged habitats. We also noted the occurrence of high (>60%) levels of outcrossing in feral alfalfa populations, establishing their role as sources and sinks for novel traits. Our findings indicate that alfalfa populations occurring in unmanaged habitats need to be considered in trait confinement protocols in order to reduce the adventitious presence (AP) of novel traits and to enhance the successful co-existence of GM and non-GM alfalfa. en
dc.format.extent 4078683 bytes
dc.format.mimetype application/pdf
dc.language.iso en_US
dc.rights info:eu-repo/semantics/openAccess
dc.subject Ferality en
dc.subject Alfalfa en
dc.subject Genetic modification en
dc.subject Novel trait confinement en
dc.title Feral nature of alfalfa (Medicago sativa L.): implications for novel trait confinement en
dc.type info:eu-repo/semantics/doctoralThesis
dc.degree.discipline Plant Science en
dc.contributor.examiningcommittee Entz, Martin (Plant Science) McLachlan, Stephane (Environment and Geography) Acharya, Surya (Agriculture and Agri-Food Canada) en
dc.degree.level Doctor of Philosophy (Ph.D.) en
dc.description.note February 2010 en


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