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- Eckert, Christopher G., et al.
(författare)
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Plant mating systems in a changing world
- 2010
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Ingår i: Trends in Ecology & Evolution. - : Elsevier BV. - 0169-5347. ; In Press, Corrected Proof
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Tidskriftsartikel (refereegranskat)abstract
- There is increasing evidence that human disturbance can negatively impact plant-pollinator interactions such as outcross pollination. We present a meta-analysis of 22 studies involving 27 plant species showing a significant reduction in the proportion of seeds outcrossed in response to anthropogenic habitat modifications. We discuss the evolutionary consequences of disturbance on plant mating systems, and in particular whether reproductive assurance through selfing effectively compensates for reduced outcrossing. The extent to which disturbance reduces pollinator versus mate availability could generate diverse selective forces on reproductive traits. Investigating how anthropogenic change influences plant mating will lead to new opportunities for better understanding of how mating systems evolve, as well as of the ecological and evolutionary consequences of human activities and how to mitigate them.
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4. |
- Goodwillie, Carol, et al.
(författare)
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Correlated evolution of mating system and floral display traits in flowering plants and its implications for the distribution of mating system variation
- 2010
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Ingår i: New Phytologist. - : Wiley. - 0028-646X .- 1469-8137. ; 185, s. 311-321
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Tidskriftsartikel (refereegranskat)abstract
- New Phytologist (2009) Reduced allocation to structures for pollinator attraction is predicted in selfing species. We explored the association between outcrossing and floral display in a broad sample of angiosperms. We used the demonstrated relationship to test for bias against selfing species in the outcrossing rate distribution, the shape of which has relevance for the stability of mixed mating. Relationships between outcrossing rate, flower size, flower number and floral display, measured as the product of flower size and number, were examined using phylogenetically independent contrasts. The distribution of floral displays among species in the outcrossing rate database was compared with that of a random sample of the same flora. The outcrossing rate was positively associated with the product of flower size and number; individually, components of display were less strongly related to outcrossing. Compared with a random sample, species in the outcrossing rate database showed a deficit of small floral display sizes. We found broad support for reduced allocation to attraction in selfing species. We suggest that covariation between mating systems and total allocation to attraction can explain the deviation from expected trade-offs between flower size and number. Our results suggest a bias against estimating outcrossing rates in the lower half of the distribution, but not specifically against highly selfing species.
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- Gutiérrez-Valencia, Juanita, 1991-
(författare)
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Genomic studies of mating system variation in flowering plants
- 2022
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The striking diversity of reproductive strategies that flowering plants exhibit remains one of the most intriguing conundrums in evolutionary biology. Pollination-related traits and mating system strategies have a major impact on the processes shaping plant evolution through their effects on genetic diversity and selection. In this thesis, I use population genomic methods to investigate the genetic underpinnings and genomic impact of cross- and self-fertilization in flowering plants. I first study the evolution and breakdown of the supergene that governs the balanced floral polymorphism of distyly in a wild flaxseed species (Linum tenue). Then I assess the consequences of shifts to self-fertilization on the intensity of sexual selection that populations experience, using the crucifer species Arabis alpina as a model. In chapters I, II and III, I investigated how the evolution of supergenes is impacted by their genetic architecture. Building on a de novo genome assembly, I used population genomic data to identify and characterize the distyly supergene in Linum tenue (chapter II). I found that the dominant allele at the distyly S-locus is defined by the presence of a 260-kb region carried in hemizygosity by thrum individuals. Importantly, the hemizygous region harbors, among others, a strong candidate gene for style length. S-linked genes did not exhibit signatures of relaxed purifying selection, consistent with expectations from previous empirical studies and forward simulations (chapter I) in suggesting that hemizygosity might slow down genetic degeneration of non-recombining haplotypes. In the light of similar studies conducted in independently evolved distylous lineages (reviewed in chapter I), our results indicate that distyly supergenes show convergent evolution at the molecular level. By conducting comparative studies of the genome sequences of L. tenue and closely related homostylous L. trigynum (chapter III), I identified candidate mutations for distyly breakdown at S-linked genes. I also investigated the genome-wide effects of the evolutionary transition to homostyly and self-fertilization in L. trigynum. I found that L. trigynum populations are highly inbred, and show significantly lower genetic diversity and more marked population structure than the obligately outcrossing L. tenue. However, I found only weak signatures of relaxed purifying selection in L. trigynum at the genome-wide scale, suggesting that self-fertilization has not had a major effect on the impact of selection. Finally, by analyzing whole-genome sequences from individuals of populations of A. alpina with contrasting mating strategies, I investigated if shifts to self-fertilization have a particularly marked impact on the evolution of genes involved in pollen-pollen competition (chapter IV). The results indicate that the reduced intensity of sexual selection that self-fertilizing populations experience translate into more pronounced signatures of relaxed purifying selection on genes expressed in male gametophyte components. Overall, this thesis contributes to our understanding of the genetic basis and evolution of plant reproductive strategies, and how they impact selection both locally and broadly across the genome.
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- Moczek, Armin P., et al.
(författare)
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The significance and scope of evolutionary developmental biology : a vision for the 21st century
- 2015
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Ingår i: Evolution & development. ; 17:3, s. 198-219
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Tidskriftsartikel (refereegranskat)abstract
- Evolutionary developmental biology (evo-devo) has undergone dramatic transformations since its emergence as a distinct discipline. This paper aims to highlight the scope, power, and future promise of evo-devo to transform and unify diverse aspects of biology. We articulate key questions at the core of eleven biological disciplines-from Evolution, Development, Paleontology, and Neurobiology to Cellular and Molecular Biology, Quantitative Genetics, Human Diseases, Ecology, Agriculture and Science Education, and lastly, Evolutionary Developmental Biology itself-and discuss why evo-devo is uniquely situated to substantially improve our ability to find meaningful answers to these fundamental questions. We posit that the tools, concepts, and ways of thinking developed by evo-devo have profound potential to advance, integrate, and unify biological sciences as well as inform policy decisions and illuminate science education. We look to the next generation of evolutionary developmental biologists to help shape this process as we confront the scientific challenges of the 21st century.
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- Pantoja, Pauline O., et al.
(författare)
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Genetic variation and clonal diversity in introduced populations of Mimulus guttatus assessed by genotyping at 62 single nucleotide polymorphism loci
- 2017
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Ingår i: Plant Ecology & Diversity. ; 10:1, s. 5-15
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Tidskriftsartikel (refereegranskat)abstract
- Background: Single nucleotide polymorphisms (SNPs) are increasingly being used to study non-native populations. SNPs are relatively information poor on a per locus basis, but allow genotyping more loci than others markers (e.g., microsatellites) and have the advantage of consistent allele calls between studies.Aims: We investigated the utility of a newly developed set of SNP markers, suitable for high throughput genotyping to characterise genotypic variation and population structure in non-native populations of the facultative clonal herb Mimulus guttatus in the United Kingdom (UK).Methods: We analysed 62 SNP markers and using a high throughput platform genotyped 383 individuals from 10 populations from the native range in North America and 14 populations in the UK.Results: We found wide variation in genotypic diversity within UK populations, indicating reproductive strategies that vary from mostly clonal to mostly sexual. All but one UK population were, on average, more closely related to each other than to North American populations, and the exceptional UK population showed strong affinity to native Alaskan plants.Conclusions: A small number of SNPs can detect patterns of clonality and broad-scale relationships between native and introduced populations. However, elucidating population structure at a finer scale will require genotyping individuals at greater depth.
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- Puzey, J. R., et al.
(författare)
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Genomics of invasion : diversity and selection in introduced populations of monkeyflowers (Mimulus guttatus)
- 2014
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Ingår i: Molecular Ecology. - 0962-1083 .- 1365-294X. ; 23:18, s. 4472-4485
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Tidskriftsartikel (refereegranskat)abstract
- Global trade and travel is irreversibly changing the distribution of species around the world. Because introduced species experience drastic demographic events during colonization and often face novel environmental challenges from their native range, introduced populations may undergo rapid evolutionary change. Genomic studies provide the opportunity to investigate the extent to which demographic, historical and selective processes shape the genomic structure of introduced populations by analysing the signature that these processes leave on genomic variation. Here, we use next-genera tion sequencing to compare genome-wide relationships and patterns of diversity in native and introduced populations of the yellow monkeyflower (Mimulus guttatus). Genome resequencing data from 10 introduced populations from the United Kingdom (UK) and 12 native M. guttatus populations in North America (NA) demonstrated reduced neutral genetic diversity in the introduced range and showed that UK populations are derived from a geographic region around the North Pacific. A selective-sweep analysis revealed site frequency changes consistent with selection on five of 14 chromosomes, with genes in these regions showing reduced silent site diversity. While the target of selection is unknown, genes associated with flowering time and biotic and abiotic stresses were located within the swept regions. The future identification of the specific source of origin of introduced UK populations will help determining whether the observed selective sweeps can be traced to unsampled native populations or occurred since dispersal across the Atlantic. Our study demonstrates the general potential of genome-wide analyses to uncover a range of evolutionary processes affecting invasive populations.
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11. |
- Simón-Porcar, Violeta I, et al.
(författare)
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Rapid local adaptation in both sexual and asexual invasive populations of monkeyflowers (Mimulus spp.)
- 2021
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Ingår i: Annals of Botany. - : Oxford University Press. - 0305-7364 .- 1095-8290. ; 127:5, s. 655-668
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Tidskriftsartikel (refereegranskat)abstract
- Background and Aims Traditionally, local adaptation has been seen as the outcome of a long evolutionary history, particularly with regard to sexual lineages. By contrast, phenotypic plasticity has been thought to be most important during the initial stages of population establishment and in asexual species. We evaluated the roles of adaptive evolution and phenotypic plasticity in the invasive success of two closely related species of invasive monkeyflowers (Mimulus) in the UK that have contrasting reproductive strategies: M. guttatus combines sexual (seeds) and asexual (clonal growth) reproduction while M.xrobertsii is entirely asexual.Methods We compared the clonality (number of stolons), floral and vegetative phenotype, and phenotypic plasticity of native (M. guttatus) and invasive (M. guttatus and M.xrobertsii) populations grown in controlled environment chambers under the environmental conditions at each latitudinal extreme of the UK. The goal was to discern the roles of temperature and photoperiod on the expression of phenotypic traits. Next, we tested the existence of local adaptation in the two species within the invasive range with a reciprocal transplant experiment at two field sites in the latitudinal extremes of the UK, and analysed which phenotypic traits underlie potential local fitness advantages in each species.Key Results Populations of M. guttatus in the UK showed local adaptation through sexual function (fruit production), while M.xrobertsii showed local adaptation via asexual function (stolon production). Phenotypic selection analyses revealed that different traits are associated with fitness in each species. Invasive and native populations of M. guttatus had similar phenotypic plasticity and clonality. M.xrobertsii presents greater plasticity and clonality than native M. guttatus, but most populations have restricted clonality under the warm conditions of the south of the UK.Conclusions This study provides experimental evidence of local adaptation in a strictly asexual invasive species with high clonality and phenotypic plasticity. This indicates that even asexual taxa can rapidly (<200 years) adapt to novel environmental conditions in which alternative strategies may not ensure the persistence of populations.
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- Simón-Porcar, Violeta I., et al.
(författare)
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Recent autopolyploidization in a naturalized population of Mimulus guttatus (Phrymaceae)
- 2017
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Ingår i: Botanical Journal of the Linnean Society. ; 185:2, s. 189-207
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Tidskriftsartikel (refereegranskat)abstract
- Polyploidization can trigger rapid changes in morphology, ecology and genomics even in the absence of associated hybridization. However, disentangling the immediate biological consequences of genome duplication from the evolutionary change that subsequently accumulates in polyploid lineages requires the identification and analysis of recently formed polyploids. We investigated the incidence of polyploidization in introduced populations of Mimulus guttatus in the UK and report the discovery of a new mixed diploid-autopolyploid population in the Shetland Isles. We conducted a genetic analysis of six Shetland populations to investigate whether tetraploid individuals may have originated from local diploid plants and compared the morphology of tetraploids and local diploids to assess the phenotypic consequences of genome duplication. Autotetraploids are genetically close to sympatric diploids, suggesting that they have originated locally. Phenotypically, whole genome duplication has resulted in clear differences between ploidies, with tetraploids showing delayed phenology and larger flowers, leaves and stems than diploids. Our results support the hypothesis that novel evolutionary lineages can rapidly originate via polyploidization. The newly discovered autopolyploidization event in a non-native Mimulus population provides an opportunity to investigate the early causes and consequences of polyploidization in the wild.
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- Vallejo-Marin, Mario, et al.
(författare)
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Division of labour within flowers : heteranthery, a floral strategy to reconcile contrasting pollen fates
- 2009
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Ingår i: Journal of Evolutionary Biology. - 1010-061X .- 1420-9101. ; 22:4, s. 828-839
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Tidskriftsartikel (refereegranskat)abstract
- In many nectarless flowering plants, pollen serves as both the carrier of male gametes and as food for pollinators. This can generate an evolutionary conflict if the use of pollen as food by pollinators reduces the number of gametes available for cross-fertilization. Heteranthery, the production of two or more stamen types by individual flowers reduces this conflict by allowing different stamens to specialize in 'pollinating' and 'feeding' functions. We used experimental studies of Solanum rostratum (Solanaceae) and theoretical models to investigate this 'division of labour' hypothesis. Flight cage experiments with pollinating bumble bees (Bombus impatiens) demonstrated that although feeding anthers are preferentially manipulated by bees, pollinating anthers export more pollen to other flowers. Evolutionary stability analysis of a model of pollination by pollen consumers indicated that heteranthery evolves when bees consume more pollen than should optimally be exchanged for visitation services, particularly when pollinators adjust their visitation according to the amount of pollen collected.
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- Vallejo-Marin, Mario, et al.
(författare)
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Harvesting pollen with vibrations: towards an integrative understanding of the proximate and ultimate reasons for buzz pollination
- 2024
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Ingår i: Annals of Botany. - 0305-7364 .- 1095-8290.
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Tidskriftsartikel (refereegranskat)abstract
- Buzz pollination, a type of interaction in which bees use vibrations to extract pollen from certain kinds of flowers, captures a close relationship between thousands of bee and plant species. In the last 120 years, studies of buzz pollination have contributed to our understanding of the natural history of buzz pollination, and basic properties of the vibrations produced by bees and applied to flowers in model systems. Yet, much remains to be done to establish its adaptive significance and the ecological and evolutionary dynamics of buzz pollination across diverse plant and bee systems. Here, we review for bees and plants the proximate (mechanism and ontogeny) and ultimate (adaptive significance and evolution) explanations for buzz pollination, focusing especially on integrating across these levels to synthesise and identify prominent gaps in our knowledge. Throughout, we highlight new technical and modelling approaches and the importance of considering morphology, biomechanics, and behaviour in shaping our understanding of the adaptive significance of buzz pollination. We end by discussing the ecological context of buzz pollination and how a multilevel perspective can contribute to explain the proximate and evolutionary reasons for this ancient bee-plant interaction.
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- Vallejo-Marin, Mario, et al.
(författare)
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On the evolutionary costs of self-incompatibility : Incomplete reproductive compensation due to pollen limitation
- 2004
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Ingår i: Evolution. - 0014-3820 .- 1558-5646. ; 58:9, s. 1924-1935
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Tidskriftsartikel (refereegranskat)abstract
- Pollen limitation affects plants with diverse reproductive systems and ecologies. In self-incompatible (SI) species, pollen limitation may preclude full reproductive compensation for prezygotic rejection of pollen. We present a model designed to explore the effects of incomplete reproductive compensation on evolutionary changes at a modifier locus that regulates the level of SI expression. Our results indicate that incomplete reproductive compensation greatly increases the evolutionary costs of SI, particularly in populations with low S-allele diversity. The evolutionary fate of modifiers of SI expression depends on the rate at which they are transmitted to future generations as well as the effects of SI on offspring number and quality. Partial SI expression can represent a stable condition rather than an evolutionarily transient state between full expression and full suppression. This unanticipated result provides the first theoretical support for the evolutionary stability of such mixed mating systems, the existence of which has recently been documented.
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20. |
- Vallejo-Marín, Mario, et al.
(författare)
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Partial interfertility between independently originated populations of the neo-allopolyploid Mimulus peregrinus
- 2017
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Ingår i: Plant Systematics and Evolution. ; 303:8, s. 1081-1092
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Tidskriftsartikel (refereegranskat)abstract
- The reduction in genetic diversity in polyploid lineages, formed from whole-genome duplication of a few individuals, can affect their long-term evolutionary potential. Because most polyploids originate multiple times, secondary contact and gene exchange among independently formed polyploids can create novel genetic combinations and reduce the severity of genetic bottlenecks. However, independently originated polyploids may be reproductively isolated from each other due to genetic and chromosomal differences predating the polyploidisation event, or evolving subsequently in the dynamic genomes of young polyploid populations. Here we conducted experimental crosses to investigate the phenotype and interfertility between two independently originated populations of the allopolyploid Mimulus peregrinus (Phrymaceae). We found that individuals from the two populations are phenotypically distinct, but that inter- and intrapopulation crosses are not statistically different. Interpopulation crosses produce viable and fertile offspring, although our results suggest the existence of partial reproductive barriers in the form of reduced pollen viability. We found no difference in pollen viability between F1 and F2 generations. In contrast, we detected a reduction in floral and vegetative size, and in the proportion of plants that flowered, between F1 and F2 generations for both intra- and interpopulation crosses. Together, our results indicate that populations of independent origin can partially exchange genes, producing variable offspring, and that the phenotype of M. peregrinus may be unstable in the early generations. Natural selection on genetically based variation may be required for the evolution of more stable and fertile individuals of this nascent allopolyploid.
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21. |
- Vallejo-Marin, Mario, et al.
(författare)
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Recurrent modification of floral morphology in heterantherous Solanum reveals a parallel shift in reproductive strategy
- 2014
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Ingår i: Philosophical Transactions of the Royal Society of London. Biological Sciences. - 0962-8436 .- 1471-2970. ; 369:1649, s. 20130256-20130256
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Tidskriftsartikel (refereegranskat)abstract
- Floral morphology determines the pattern of pollen transfer within and between individuals. In hermaphroditic species, the spatial arrangement of sexual organs influences the rate of self-pollination as well as the placement of pollen in different areas of the pollinator's body. Studying the evolutionary modification of floral morphology in closely related species offers an opportunity to investigate the causes and consequences of floral variation. Here, we investigate the recurrent modification of flower morphology in three closely related pairs of taxa in Solanum section Androceras (Solanaceae), a group characterized by the presence of two morphologically distinct types of anthers in the same flower (heteranthery). We use morphometric analyses of plants grown in a common garden to characterize and compare the changes in floral morphology observed in parallel evolutionary transitions from relatively larger to smaller flowers. Our results indicate that the transition to smaller flowers is associated with a reduction in the spatial separation of anthers and stigma, changes in the allometric relationships among floral traits, shifts in pollen allocation to the two anther morphs and reduced pollen : ovule ratios. We suggest that floral modification in this group reflects parallel evolution towards increased self-fertilization and discuss potential selective scenarios that may favour this recurrent shift in floral morphology and function.
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- Vallejo-Marin, Mario, et al.
(författare)
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The Ecological and Evolutionary Consequences of Clonality for Plant Mating
- 2010
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Ingår i: Annual Review of Ecology Evolution and Systematics. - 9780824314415 ; 41, s. 193-213
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Tidskriftsartikel (refereegranskat)abstract
- Many flowering plants exhibit dull reproductive modes, producing both sexual and asexual offspring The commonest form of asexual reproduction is clonal growth, in which vegetative modules (ramets) are produced by the parental genotype (genet) In plants, sexual and asexual reproduction usually occur simultineously, and this can lead to allocation trade-offs and antagonism between reproductive modes Our review considers the ecological and evolutionary consequences of functional interactions between clonal reproduction and pollination and mating Clonal reproduction is commonly associated with mass flowering, restricted pollen dispersal, and geitonogamous self-pollination, processes that can result in inbreeding depression and pollen discounting We review evidence for the correlated evolution of clonality and sexual systems, particularly self-incompatibility, and Identify several floral mechanisms that function to reduce mating costs by limiting selfing and pollen discounting We conclude by discussing the loss of sexuality in clonal plants and consider the genetic and environmental basis of sexual dysfunction
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- Vallejo-Marín, Mario, et al.
(författare)
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Thirteen microsatellites developed by SSR-enriched pyrosequencing for Solanum rostratum (Solanaceae) and related species
- 2011
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Ingår i: American Journal of Botany. ; 98:10, s. e296-e299
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Tidskriftsartikel (refereegranskat)abstract
- • Premise of the study: Microsatellite markers were developed using second-generation sequencing in Solanum rostratum as a tool to study the reproductive biology and genetic structure of this invasive species.• Methods and Results: Thirteen microsatellites were successfully discovered and amplified in a single multiplexed PCR. All loci showed genetic variation in S. rostratum. Cross-amplification in five closely related taxa was successful for a subset of loci.• Conclusions: The set of 13 microsatellite markers developed here provides a time-effective and cost-effective genetic tool to study the reproductive biology of S. rostratum. The demonstrated transferability of the PCR multiplex to related taxa also highlights its usefulness for evolutionary studies across Solanum sect. Androceras.
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24. |
- Wilkins, Rachel V., et al.
(författare)
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Hold tight or loosen up? : Functional consequences of a shift in anther architecture depend substantially on bee body size
- 2022
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Ingår i: Oecologia. - : Springer Nature. - 0029-8549 .- 1432-1939. ; 200:1-2, s. 119-131
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Tidskriftsartikel (refereegranskat)abstract
- A fundamental question in pollination ecology is how pollinators affect the evolution of different floral forms. Yet functional effects of shifts in floral form for plant and pollinator are frequently unclear. For instance, flowers that conceal pollen within tube-like anthers that are spread apart and move freely (free architecture) or are tightly joined together (joined architecture) have evolved independently across diverse plant families and are geographically widespread. Surprisingly, how their bee pollinators affect the function of both architectures remains unknown. We hypothesised that bee body size would affect foraging success and pollination differently for free and joined anther architectures. Therefore, we modified the anther architecture of a single plant species (Solanum elaeagnifolium) and used a single species of generalist bumble bee (Bombus impatiens), which varies greatly in body size. We found that on free anther architecture, larger bees were better pollinators. More pollen on their bodies was available for pollination and they deposited more pollen on stigmas. Conversely, on joined anther architecture, smaller bees were better pollinators. They collected less pollen into their pollen baskets, had more pollen on their bodies available for pollination, and deposited more pollen on stigmas. While we also found modest evidence that plants benefit more from joined versus free anther architecture, further investigation will likely reveal this also depends on pollinator traits. We discuss potential mechanisms by which pollinator size and anther architecture interact and implications for floral evolution.
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25. |
- Winn, Alice A., et al.
(författare)
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Analysis of inbreeding depression in mixed-mating plants provides evidence for selective interference and stable mixed mating
- 2011
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Ingår i: Evolution. - : Wiley. - 0014-3820 .- 1558-5646. ; , s. 10.1111/j.1558-5646.2011.01462.x
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Tidskriftsartikel (refereegranskat)abstract
- Hermaphroditic individuals can produce both selfed and outcrossed progeny, termed mixed mating. General theory predicts that mixed-mating populations should evolve quickly toward high rates of selfing, driven by rapid purging of genetic load and loss of inbreeding depression (ID), but the substantial number of mixed-mating species observed in nature calls this prediction into question. Lower average ID reported for selfing than for outcrossing populations is consistent with purging and suggests that mixed-mating taxa in evolutionary transition will have intermediate ID. We compared the magnitude of ID from published estimates for highly selfing (r > 0.8), mixed-mating (0.2 ?r? 0.8), and highly outcrossing (r < 0.2) plant populations across 58 species. We found that mixed-mating and outcrossing taxa have equally high average lifetime ID (?= 0.58 and 0.54, respectively) and similar ID at each of four life-cycle stages. These results are not consistent with evolution toward selfing in most mixed-mating taxa. We suggest that prevention of purging by selective interference could explain stable mixed mating in many natural populations. We identify critical gaps in the empirical data on ID and outline key approaches to filling them.
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