| 1. |
- Burdon, Jeremy J., et al.
(författare)
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Genes, communities & invasive species : understanding the ecological and evolutionary dynamics of host-pathogen interactions
- 2013
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Ingår i: Current opinion in plant biology. - : Elsevier BV. - 1369-5266 .- 1879-0356. ; 16:4, s. 400-405
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Forskningsöversikt (refereegranskat)abstract
- Reciprocal interactions between hosts and pathogens drive ecological, epidemiological and co-evolutionary trajectories, resulting in complex patterns of diversity at population, species and community levels. Recent results confirm the importance of negative frequency-dependent rather than 'arms-race' processes in the evolution of individual host-pathogen associations. At the community level, complex relationships between species abundance and diversity dampen or alter pathogen impacts. Invasive pathogens challenge these controls reflecting the earliest stages of evolutionary associations (akin to arms-race) where disease effects may be so great that they overwhelm the host's and community's ability to respond. Viewing these different stabilization/destabilization phases as a continuum provides a valuable perspective to assessment of the role of genetics and ecology in the dynamics of both natural and invasive host-pathogen associations.
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| 2. |
- Burdon, Jeremy J., et al.
(författare)
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The current and future dynamics of disease in plant communities
- 2006
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Ingår i: Annual Review of Phytopathology. - : Annual Reviews. - 0066-4286 .- 1545-2107. ; 44, s. 19-39
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Tidskriftsartikel (refereegranskat)abstract
- Pathogens are powerful evolutionary forces shaping the structure and dynamics of both individual species and of the communities of which they are part, at a broad range of genetic, ecological, spatial, and temporal scales. At all these levels their impact varies from the subtle and little recognized through to the most obvious destruction. Today the direct role of pathogens in natural plant communities is better recognized than at previous times, although the nuances of their interactions and the cascade of ramifications that can flow through changing biotic and abiotic effects are only now gaining recognition. However, as human influence on pathogens increases either directly through enhanced if accidental dispersal, or through anthropogenic impacts on climate-we may expect to see increasing evidence of pathogens affecting plant species, community structure, and ecosystem function.
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| 3. |
- Carlsson-Graner, Ulla, et al.
(författare)
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Host resistance and pathogen infectivity in host populations with varying connectivity
- 2015
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Ingår i: Evolution. - : Wiley. - 0014-3820 .- 1558-5646. ; 69:4, s. 926-938
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Tidskriftsartikel (refereegranskat)abstract
- Theory predicts that hosts and pathogens will evolve higher resistance and aggressiveness in systems where populations are spatially connected than in situations in which populations are isolated and dispersal is more local. In a large cross-inoculation experiment we surveyed patterns of host resistance and pathogen infectivity in anther-smut diseased Viscaria alpina populations from three contrasting areas where populations range from continuous, through patchy but spatially connected to highly isolated demes. In agreement with theory, isolated populations of V. alpina were more susceptible on average than either patchily distributed or continuous populations. While increased dispersal in connected systems increases disease spread, it may also increase host gene flow and the potential for greater host resistance to evolve. In the Viscaria-Microbotryum system, pathogen infectivity mirrored patterns of host resistance with strains from the isolated populations being the least infective and strains from the more resistant continuous populations being the most infective on average, suggesting that high resistance selects for high infectivity. To our knowledge this study is the first to characterize the impacts of varying spatial connectivity on patterns of host resistance and pathogen infectivity in a natural system.
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| 4. |
- Carlsson-Granér, Ulla, et al.
(författare)
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The spatial distribution of plant populations, disease dynamics and evolution of resistance
- 2002
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Ingår i: Oikos. - : Wiley. - 0030-1299 .- 1600-0706. ; 97:1, s. 97-110
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Tidskriftsartikel (refereegranskat)abstract
- Empirical studies of the interaction between the anther smut fungus Microbotryum violaceum and its host plant Lychnis alpina were combined with modelling approaches to investigate how variation in the spatial distribution of host populations influences disease dynamics and variation in resistance. Patterns of disease incidence and prevalence were surveyed in three contrasting systems of natural L. alpina populations where there is substantial variation in spatial structure, ranging from large continuous populations through to small isolated patches. Disease incidence (fraction of populations where disease was present) was highest in the continuous situation, and lowest in the most isolated populations. The reverse was true for prevalence (fraction of individuals diseased). To better understand the long-term ecological and evolutionary consequences of differences in among population spatial structure, we developed a two-dimensional spatially explicit simulation model in which host-population spacing was modelled by varying the percentage of sites suitable for the host. The general patterns of disease incidence and prevalence generated in the simulations corresponded well with the patterns observed in natural populations of L. alpina and M. violaceum; i.e. the fraction of sites with disease increased while the average disease prevalence in diseased populations decreased when host populations became more connected. One likely explanation for the differences in disease incidence and prevalence seen in natural populations is that the evolution of host resistance varies as a function of the degree of fragmentation. This is supported by simulation results that were qualitatively similar to the survey data when resistance was allowed to vary, but not when hosts were assumed to be uniformly susceptible. In the former, the frequency of resistance increased markedly as host populations became more connected.
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| 5. |
- Tack, Ayco J. M., et al.
(författare)
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Below-ground abiotic and biotic heterogeneity shapes above-ground infection outcomes and spatial divergence in a host-parasite interaction
- 2015
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Ingår i: New Phytologist. - : Wiley. - 0028-646X .- 1469-8137. ; 207:4, s. 1159-1169
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Tidskriftsartikel (refereegranskat)abstract
- We investigated the impact of below-ground and above-ground environmental heterogeneity on the ecology and evolution of a natural plant-pathogen interaction. We combined field measurements and a reciprocal inoculation experiment to investigate the potential for natural variation in abiotic and biotic factors to mediate infection outcomes in the association between the fungal pathogen Melampsora lini and its wild flax host, Linum marginale, where pathogen strains and plant lines originated from two ecologically distinct habitat types that occur in close proximity (bog' and hill'). The two habitat types differed strikingly in soil moisture and soil microbiota. Infection outcomes for different host-pathogen combinations were strongly affected by the habitat of origin of the plant lines and pathogen strains, the soil environment and their interactions. Our results suggested that tradeoffs play a key role in explaining the evolutionary divergence in interaction traits among the two habitat types. Overall, we demonstrate that soil heterogeneity, by mediating infection outcomes and evolutionary divergence, can contribute to the maintenance of variation in resistance and pathogenicity within a natural host-pathogen metapopulation.
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