1
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Stewart AB, Srilopan S, Wayo K, Hassa P, Dudash MR, Bumrungsri S. Bat pollinators: a decade of monitoring reveals declining visitation rates for some species in Thailand. Zoological Lett 2024; 10:5. [PMID: 38431697 PMCID: PMC10908063 DOI: 10.1186/s40851-024-00228-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/23/2023] [Accepted: 02/03/2024] [Indexed: 03/05/2024]
Abstract
Bats are important pollinators, but they are difficult to study since they are volant and nocturnal. Thus, long-term studies of nectarivorous bats are scarce, despite their potential to help assess trends in bat populations and their pollination services. We used capture rates of nectarivorous bats at chiropterophilous flowers in order to examine temporal trends in bat visitation in an area that is undergoing extensive land use change. We mist-netted at five bat-pollinated plant taxa (Durio zibethinus, Musa acuminata, Oroxylum indicum, Parkia speciosa, and Sonneratia spp.) in southern Thailand over six years between 2011 and 2021. We found that the most common bat species, Eonycteris spelaea, was the main visitor at all five plant taxa and had consistent visitation rates across all study years. In contrast, two other important pollinators, Macroglossus minimus and M. sobrinus, showed 80% declines in the number of individuals netted at mangrove apple (Sonneratia spp.) and banana (Musa acuminata) flowers, respectively. These findings suggest that E. spelaea (a large, cave-roosting species with a broad diet) is more tolerant of anthropogenic change than are Macroglossus bats (small, foliage-roosting species with specialized diets), which may in turn affect the reproductive success of plants pollinated by these species. Our study demonstrates how decade-long monitoring can reveal species-specific temporal patterns in pollinator visitation, emphasizing the need for tailored conservation plans. While the conservation status of most nectarivorous bats in the area is Least Concern, our results indicate that population studies in Southeast Asia are urgently needed for updated bat species conservation assessments.
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Affiliation(s)
- Alyssa B Stewart
- Department of Plant Science, Faculty of Science, Mahidol University, Bangkok, Thailand.
| | - Supawan Srilopan
- Department of Biology, Prince of Songkla University, Hat Yai, Songkhla, Thailand
| | - Kanuengnit Wayo
- Department of Biology, Prince of Songkla University, Hat Yai, Songkhla, Thailand
| | - Piriya Hassa
- Department of Plant Science, Faculty of Science, Mahidol University, Bangkok, Thailand
| | - Michele R Dudash
- Department of Natural Resource Management, South Dakota State University, Brookings, SD, USA
- Department of Biology, University of Maryland, College Park, MD, USA
| | - Sara Bumrungsri
- Department of Biology, Prince of Songkla University, Hat Yai, Songkhla, Thailand
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2
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Zimmer EA, Berg JA, Dudash MR. Genetic diversity and population structure among native, naturalized, and invasive populations of the common yellow monkeyflower, Mimulus guttatus (Phrymaceae). Ecol Evol 2023; 13:e9596. [PMID: 37038527 PMCID: PMC10082173 DOI: 10.1002/ece3.9596] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2021] [Revised: 03/01/2022] [Accepted: 03/28/2022] [Indexed: 04/12/2023] Open
Abstract
An ongoing controversy in invasion biology is the prevalence of colonizing plant populations that are able to establish and spread, while maintaining limited amounts of genetic variation. Invasive populations can be established through several routes including from a single source or from multiple introductions. The aim of this study was to examine genetic diversity in populations of Mimulus guttatus in the United Kingdom, where the species is considered invasive, and compare this diversity to that in native populations on the west coast of North America. Additionally, we looked at diversity in non-native populations that have not yet become invasive (naturalized populations) in eastern North America. We investigated population structure among populations in these three regions and attempted to uncover the sources for populations that have established in the naturalized and invasive regions. We found that genetic diversity was, on average, relatively high in populations from the invasive UK region and comparable to native populations. Contrastingly, two naturalized M. guttatus populations were low in both genetic and genotypic diversity, indicating a history of asexual reproduction and self-fertilization. A third naturalized population was found to be a polyploid Mimulus hybrid of unknown origin. Our results demonstrate that M. guttatus has likely achieved colonization success outside of its native western North America distribution by a variety of establishment pathways, including those with genetic and demographic benefits resulting from multiple introductions in the UK, reproductive assurance through selfing, and asexual reproduction in eastern North America, and possible polyploidization in one Canadian population.
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Affiliation(s)
- Elizabeth A. Zimmer
- Department of Botany and Laboratories of Analytical Biology, National Museum of Natural HistorySmithsonian InstitutionWashingtonDistrict of ColumbiaUSA
| | - Jason A. Berg
- Department of Biological SciencesUniversity of MarylandCollege ParkMarylandUSA
| | - Michele R. Dudash
- Department of Biological SciencesUniversity of MarylandCollege ParkMarylandUSA
- Department of Natural Resource ManagementSouth Dakota State UniversityBrookingsSouth DakotaUSA
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3
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Stewart AB, Diller C, Dudash MR, Fenster CB. Pollination-precision hypothesis: support from native honey bees and nectar bats. New Phytol 2022; 235:1629-1640. [PMID: 35194792 DOI: 10.1111/nph.18050] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/25/2021] [Accepted: 02/09/2022] [Indexed: 05/28/2023]
Abstract
The evolution of floral traits is often considered to reflect selection for increased pollination efficiency. Known as the pollination-precision hypothesis, increased pollination efficiency is achieved by enhancing pollen deposition on precise areas of the pollinator. Most research to date addressing this hypothesis has examined plant species that are a priori predicted to place pollen precisely, but we still lack comparisons with species predicted to have low pollination efficiency. We studied 39 plant species with diverse floral morphologies and measured the precision of pollen placement on two pollinator groups: honey bees (genus Apis) and nectar bats (family Pteropodidae). Pollen was collected from four locations of each pollinator's body (bees: dorsal thorax, ventral thorax, dorsal abdomen, ventral abdomen; bats: crown, face, chest, wing) to calculate pollen placement precision using Pielou's evenness index. We also quantified variation in floral design by scoring floral symmetry, corolla fusion, floral orientation and stamen number. We confirm the importance of four floral character states (bilateral symmetry, fused corollas, horizontal orientation and reduced stamen number) in promoting precise pollen placement on diverse pollinators. Our findings provide phylogenetically corrected, empirical support that the evolution of the four floral characters reflect selection for enhanced precision of pollen placed on pollinators.
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Affiliation(s)
- Alyssa B Stewart
- Department of Plant Science, Faculty of Science, Mahidol University, Bangkok, 10400, Thailand
| | - Carolina Diller
- Department of Plant Protection Biology, Swedish University of Agricultural Sciences, Alnarp, 234 56, Sweden
| | - Michele R Dudash
- Department of Natural Resource Management, South Dakota State University, Brookings, SD, 57007, USA
- Department of Biology, University of Maryland, College Park, MD, 20742, USA
| | - Charles B Fenster
- Oak Lake Field Station, South Dakota State University, Brookings, SD, 57007, USA
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4
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Stanley CQ, Dudash MR, Ryder TB, Gregory Shriver W, Marra PP. Variable tropical moisture and food availability underlie mixed winter space-use strategies in a migratory songbird. Proc Biol Sci 2021; 288:20211220. [PMID: 34284621 PMCID: PMC8292764 DOI: 10.1098/rspb.2021.1220] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2021] [Accepted: 06/30/2021] [Indexed: 11/20/2022] Open
Abstract
Identifying environmental correlates driving space-use strategies can be critical for predicting population dynamics; however, such information can be difficult to attain for small mobile species such as migratory songbirds. We combined radio-telemetry and high-resolution GPS tracking to examine space-use strategies under different moisture gradients for wood thrush (Hylocichla mustelina). We explored the role moisture plays in driving food abundance and, in turn, space-use strategies at a wintering site in Belize across 3 years. Individuals occupying drier habitats experienced lower food abundance and poorer body condition. Using data from our radio-tracked study population and GPS tracking from across five breeding populations, we detected low rates of overwinter site persistence across the wood thrush wintering range. Contrary to expectations, individuals in wetter habitats were more likely to engage in permanent mid-winter relocations, up to 148 km. We suggest facultative movements are instead a condition-dependent strategy that enables wintering wood thrush to locate alternative habitat as food availability declines throughout the dry season. Increased aridity is predicted across the wintering range of wood thrush, and future research should delve deeper into understanding how moisture impacts within and between season space-use dynamics and its ultimate impact on the population dynamics of this declining species.
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Affiliation(s)
- Calandra Q. Stanley
- Migratory Bird Center, Smithsonian Conservation Biology Institute, Washington, DC 20008, USA
- Graduate Program in Behaviour, Ecology, Evolution, and Systematics, University of Maryland, College Park, MD 20742, USA
- Department of Biology and McCourt School of Public Policy, Georgetown University, 37th and O Streets NW, Washington, DC 20057, USA
| | - Michele R. Dudash
- Department of Natural Resource Management, South Dakota State University, Brookings, SD 57007, USA
| | - Thomas B. Ryder
- Migratory Bird Center, Smithsonian Conservation Biology Institute, Washington, DC 20008, USA
- Bird Conservancy of the Rockies, 230 Cherry Street, Suite 150, Fort Collins, CO 80521, USA
| | - W. Gregory Shriver
- Department of Entomology and Wildlife Ecology, University of Delaware, Newark, DE 19716, USA
| | - Peter P. Marra
- Migratory Bird Center, Smithsonian Conservation Biology Institute, Washington, DC 20008, USA
- Department of Biology and McCourt School of Public Policy, Georgetown University, 37th and O Streets NW, Washington, DC 20057, USA
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5
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Stanley CQ, Dudash MR, Ryder TB, Shriver WG, Serno K, Adalsteinsson S, Marra PP. Seasonal variation in habitat selection for a Neotropical migratory songbird using high‐resolution GPS tracking. Ecosphere 2021. [DOI: 10.1002/ecs2.3421] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Affiliation(s)
- Calandra Q. Stanley
- Migratory Bird Center Smithsonian Conservation Biology Institute Washington D. C.20008USA
- Graduate Program in Behavior, Ecology, Evolution, and Systematics University of Maryland College Park Maryland20742USA
- Department of Biology and McCourt School of Public Policy Georgetown University 37th and O Streets NW Washington D. C.20057USA
| | - Michele R. Dudash
- Department of Natural Resource Management South Dakota State University Brookings South Dakota57007USA
| | - Thomas B. Ryder
- Migratory Bird Center Smithsonian Conservation Biology Institute Washington D. C.20008USA
- Bird Conservancy of the Rockies 230 Cherry St, Suite 150 Fort Collins Colorado80521USA
| | - W. Gregory Shriver
- Department of Entomology and Wildlife Ecology University of Delaware Newark Delaware19716USA
| | - Kimberly Serno
- Department of Entomology and Wildlife Ecology University of Delaware Newark Delaware19716USA
| | - Solny Adalsteinsson
- Department of Entomology and Wildlife Ecology University of Delaware Newark Delaware19716USA
- Tyson Research Center Washington University in St. Louis 6750 Tyson Valley Road Eureka Missouri63025USA
| | - Peter P. Marra
- Migratory Bird Center Smithsonian Conservation Biology Institute Washington D. C.20008USA
- Department of Biology and McCourt School of Public Policy Georgetown University 37th and O Streets NW Washington D. C.20057USA
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6
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Ahlering MA, Cornett M, Blann K, White M, Lenhart C, Dixon C, Dudash MR, Johnson L, Keeler B, Palik B, Pastor J, Sterner RW, Shaw D, Biske R, Feeken N, Manolis J, Possingham H. A conservation science agenda for a changing Upper Midwest and Great Plains,
United States. Conservat Sci and Prac 2020. [DOI: 10.1111/csp2.236] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Affiliation(s)
| | | | | | - Mark White
- The Nature Conservancy Arlington Virginia USA
| | | | - Cami Dixon
- U.S. Fish & Wildlife Service Washington District of Columbia USA
| | | | | | | | - Brian Palik
- USDA Forest Service Northern Research Station Grand Rapids Minnesota USA
| | - John Pastor
- University of Minnesota Duluth Duluth Minnesota USA
| | | | - Doug Shaw
- The Nature Conservancy Arlington Virginia USA
| | | | - Neal Feeken
- The Nature Conservancy Arlington Virginia USA
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7
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Zhou J, Reynolds RJ, Zimmer EA, Dudash MR, Fenster CB. Variable and sexually conflicting selection on
Silene stellata
floral traits by a putative moth pollinator selective agent. Evolution 2020; 74:1321-1334. [DOI: 10.1111/evo.13965] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2019] [Revised: 02/21/2020] [Accepted: 03/13/2020] [Indexed: 10/24/2022]
Affiliation(s)
- Juannan Zhou
- Simons Center for Quantitative Biology Cold Spring Harbor Laboratory Cold Spring Harbor NY 11724 USA
| | - Richard J. Reynolds
- Division of Clinical Immunology and Rheumatology, Department of Medicine University of Alabama at Birmingham Birmingham AL 35294 USA
| | - Elizabeth A. Zimmer
- Department of Botany National Museum of Natural History, MRC 166 Smithsonian Institution Washington DC 20013–7012 USA
| | - Michele R. Dudash
- Department of Natural Resource Management South Dakota State University Brookings SD 57007 USA
| | - Charles B. Fenster
- Department of Biology and Microbiology South Dakota State University Brookings SD 57007 USA
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8
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Fenster CB, Ballou JD, Dudash MR, Eldridge MDB, Frankham R, Lacy RC, Ralls K, Sunnucks P. Conservation and Genetics. Yale J Biol Med 2018; 91:491-501. [PMID: 30588214 PMCID: PMC6302618] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Humans are responsible for a cataclysm of species extinction that will change the world as we see it, and will adversely affect human health and wellbeing. We need to understand at individual and societal levels why species conservation is important. Accepting the premise that species have value, we need to next consider the mechanisms underlying species extinction and what we can do to reverse the process. One of the last stages of species extinction is the reduction of a species to a few populations of relatively few individuals, a scenario that leads invariably to inbreeding and its adverse consequences, inbreeding depression. Inbreeding depression can be so severe that populations become at risk of extinction not only because of the expression of harmful recessive alleles (alleles having no phenotypic effect when in the heterozygous condition, e.g., Aa, where a is the recessive allele), but also because of their inability to respond genetically with sufficient speed to adapt to changing environmental conditions. However, new conservation approaches based on foundational quantitative and population genetic theory advocate for active genetic management of fragmented populations by facilitating gene movements between populations, i.e., admixture, or genetic rescue. Why species conservation is critical, the genetic consequences of small population size that often lead to extinction, and possible solutions to the problem of small population size are discussed and presented.
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Affiliation(s)
- Charles B. Fenster
- Department of Biology and Microbiology, South Dakota State University, Brookings, SD
| | - Jonathan D. Ballou
- Center for Conservation Genomics, Smithsonian Conservation Biology Institute, Washington, DC
| | - Michele R. Dudash
- Department of Natural Resource Management, South Dakota State University, Brookings, SD
| | - Mark D. B. Eldridge
- Australian Museum Research Institute, Australian Museum, Sydney, NSW, Australia
| | - Richard Frankham
- Macquarie University and Australian Museum, Sydney, NSW, Australia
| | | | - Katherine Ralls
- Center for Conservation Genomics, Smithsonian Conservation Biology Institute, Washington, DC
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9
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Zhou J, Zimmer EA, Fenster CB, Dudash MR. Characterization of the mating system of a native perennial tetraploid herb, Silene stellata. Am J Bot 2018; 105:1643-1652. [PMID: 30276803 DOI: 10.1002/ajb2.1158] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/28/2018] [Accepted: 07/16/2018] [Indexed: 06/08/2023]
Abstract
PREMISE OF THE STUDY Nursery pollination systems can range from obligate to facultative. In a system where generalists provide substantial pollination service, an important question is whether the cost of seed predation outweighs the benefit provided by the nursery pollinator to cause the plant to evolve toward more generalized pollination. Using a facultative system native to North America, we tested whether nursery pollinator vs. strictly mutualistic generalists affect mating-system parameters of the host plant and explored the implications for long-term coevolution. METHODS We used paternity analyses with 11 microsatellite markers to characterize the mating system of Silene stellata when pollination service is primarily through the nursery pollinator Hadena ectypa and generalist moths. KEY RESULTS Our experimental population of S. stellata was predominantly outcrossing (average outcrossing rate t = 0.83), and mating-system parameters were similar between pollinator groups. We detected significant correlations in both selfing and outcrossed paternity at the fruit and maternal family level, corresponding to limited pollen dispersal (mean = 3.9 m). Among individuals, variation in anther-stigma separation was positively associated with outcrossing rate, which suggests the importance of herkogamy in preventing selfing. CONCLUSIONS Correlated paternity suggests that seeds from the same fruit and/or plants are sired by a limited number of pollen donors, resulting from low pollen dispersal and potential male-male competition. The similar mating-system parameters of the two pollinator groups suggest that selection for higher outcrossing in S. stellata is likely to be through floral design rather than through increased pollinator specialization with H. ectypa.
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Affiliation(s)
- Juannan Zhou
- Simons Center for Quantitative Biology, Cold Spring Harbor Laboratory, Cold Spring Harbor, New York, 11724, USA
| | - Elizabeth A Zimmer
- Department of Botany, National Museum of Natural History, MRC 166, Smithsonian Institution, Washington, D.C., 20013, USA
| | - Charles B Fenster
- Department of Biology and Microbiology, South Dakota State University, Brookings, South Dakota, 57007, USA
| | - Michele R Dudash
- Department of Natural Resource Management, South Dakota State University, Brookings, South Dakota, 57007, USA
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10
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Zhou J, Dudash MR, Zimmer EA, Fenster CB. Comparison of population genetic structures of the plant Silene stellata and its obligate pollinating seed predator moth Hadena ectypa. Ann Bot 2018; 122:593-603. [PMID: 29850821 PMCID: PMC6153480 DOI: 10.1093/aob/mcy091] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/05/2017] [Accepted: 05/03/2018] [Indexed: 05/29/2023]
Abstract
BACKGROUND AND AIMS Population genetic structures and patterns of gene flow of interacting species provide important insights into the spatial scale of their interactions and the potential for local co-adaptation. We analysed the genetic structures of the plant Silene stellata and the nocturnal moth Hadena ectypa. Hadena ectypa acts as one of the important pollinators of S. stellata as well as being an obligate seed parasite on the plant. Although H. ectypa provides a substantial pollination service to S. stellata, this system is largely considered parasitic due to the severe seed predation by the Hadena larvae. Previous research on this system has found variable interaction outcomes across space, indicating the potential for a geographical selection mosaic. METHODS Using 11 microsatellite markers for S. stellata and nine markers for H. ectypa, we analysed the population genetic structure and the patterns and intensity of gene flow within and among three local populations in the Appalachians. KEY RESULTS We found no spatial genetic structure in the moth populations, while significant differentiation was detected among the local plant populations. Additionally, we observed that gene flow rates among H. ectypa populations were more uniform and that the mean gene flow rate in H. ectypa was twice as large as that in S. stellata. CONCLUSIONS Our results suggest that although the moths move frequently among populations, long-distance pollen carryover only happens occasionally. The difference in gene flow rates between S. stellata and H. ectypa could prevent strict local co-adaptation. Furthermore, higher gene flow rates in H. ectypa could also increase resistance of the local S. stellata populations to the parasitic effect of H. ectypa and therefore help to stabilize the Silene-Hadena interaction dynamics.
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Affiliation(s)
- Juannan Zhou
- Simons Center for Quantitative Biology, Cold Spring Harbor Laboratory, Cold Spring Harbor, NY, USA
| | - Michele R Dudash
- Department of Natural Resource Management, South Dakota State University, Brookings, SD, USA
| | - Elizabeth A Zimmer
- Department of Botany, National Museum of Natural History, MRC 166, Smithsonian Institution, Washington, DC, USA
| | - Charles B Fenster
- Department of Biology and Microbiology, South Dakota State University, Brookings, SD, USA
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11
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Affiliation(s)
- Charles B Fenster
- Department of Biology and Microbiology and the Department of Natural Resource Management, respectively, at South Dakota State University, in Brookings
| | - Michele R Dudash
- Department of Biology and Microbiology and the Department of Natural Resource Management, respectively, at South Dakota State University, in Brookings
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12
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Ralls K, Ballou JD, Dudash MR, Eldridge MDB, Fenster CB, Lacy RC, Sunnucks P, Frankham R. Call for a Paradigm Shift in the Genetic Management of Fragmented Populations. Conserv Lett 2017. [DOI: 10.1111/conl.12412] [Citation(s) in RCA: 209] [Impact Index Per Article: 29.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
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13
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Stewart AB, Dudash MR. Foraging strategies of generalist and specialist Old World nectar bats in response to temporally variable floral resources. Biotropica 2017. [DOI: 10.1111/btp.12492] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Alyssa B. Stewart
- Department of Biology; University of Maryland; College Park MD 20742 USA
- Department of Plant Science; Faculty of Science; Mahidol University; Bangkok 10400 Thailand
| | - Michele R. Dudash
- Department of Biology; University of Maryland; College Park MD 20742 USA
- Department of Natural Resource Management; South Dakota State University; Brookings SD 57007 USA
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14
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Dudash MR. RELATIVE FITNESS OF SELFED AND OUTCROSSED PROGENY IN A SELF-COMPATIBLE, PROTANDROUS SPECIES, SABATIA ANGULARIS
L. (GENTIANACEAE): A COMPARISON IN THREE ENVIRONMENTS. Evolution 2017; 44:1129-1139. [DOI: 10.1111/j.1558-5646.1990.tb05220.x] [Citation(s) in RCA: 255] [Impact Index Per Article: 36.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/1989] [Accepted: 12/20/1989] [Indexed: 11/28/2022]
Affiliation(s)
- Michele R. Dudash
- Department of Biological Sciences; University of Illinois at Chicago; Chicago IL 60680 USA
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15
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Carr DE, Fenster CB, Dudash MR. THE RELATIONSHIP BETWEEN MATING‐SYSTEM CHARACTERS AND INBREEDING DEPRESSION IN
MIMULUS GUTTATUS. Evolution 2017; 51:363-372. [DOI: 10.1111/j.1558-5646.1997.tb02423.x] [Citation(s) in RCA: 39] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/1996] [Accepted: 12/06/1996] [Indexed: 11/30/2022]
Affiliation(s)
- David E. Carr
- Department of Plant Biology University of Maryland College Park Maryland 20742‐5815
| | - Charles B. Fenster
- Department of Plant Biology University of Maryland College Park Maryland 20742‐5815
| | - Michele R. Dudash
- Department of Plant Biology University of Maryland College Park Maryland 20742‐5815
- Maryland Agriculture Experiment Station University of Maryland College Park Maryland 20742‐5815
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16
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Carr DE, Dudash MR. THE EFFECTS OF FIVE GENERATIONS OF ENFORCED SELFING ON POTENTIAL MALE AND FEMALE FUNCTION IN
MIMULUS GUTTATUS. Evolution 2017; 51:1797-1807. [DOI: 10.1111/j.1558-5646.1997.tb05103.x] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/1996] [Accepted: 08/11/1997] [Indexed: 11/28/2022]
Affiliation(s)
- David E. Carr
- Departments of Plant Biology and Zoology University of Maryland College Park Maryland 20742
| | - Michele R. Dudash
- Departments of Plant Biology and Zoology University of Maryland College Park Maryland 20742
- Maryland Agricultural Experiment Station University of Maryland College Park Maryland 20742
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17
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Dudash MR, Carr DE, Fenster CB. FIVE GENERATIONS OF ENFORCED SELFING AND OUTCROSSING IN
MIMULUS GUTTATUS
: INBREEDING DEPRESSION VARIATION AT THE POPULATION AND FAMILY LEVEL. Evolution 2017; 51:54-65. [DOI: 10.1111/j.1558-5646.1997.tb02388.x] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/1995] [Accepted: 08/02/1996] [Indexed: 11/29/2022]
Affiliation(s)
- Michele R. Dudash
- Department of Plant Biology University of Maryland College Park Maryland 20742‐5815
- Maryland Agricultural Experiment Station University of Maryland College Park Maryland 20742‐5815
| | - David E. Carr
- Department of Plant Biology University of Maryland College Park Maryland 20742‐5815
| | - Charles B. Fenster
- Department of Plant Biology University of Maryland College Park Maryland 20742‐5815
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18
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Stewart AB, Dudash MR. Field evidence of strong differential pollen placement by Old World bat-pollinated plants. Ann Bot 2017; 119:73-79. [PMID: 27864223 PMCID: PMC5218376 DOI: 10.1093/aob/mcw212] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/21/2016] [Revised: 08/01/2016] [Accepted: 09/03/2016] [Indexed: 06/01/2023]
Abstract
BACKGROUND AND AIMS Sympatric plant species that share pollinators potentially compete for pollination and risk interspecific pollen transfer, but this competition can be minimized when plant species place pollen on different areas of the pollinator's body. Multiple studies have demonstrated strong differential pollen placement by sympatric plant species under laboratory conditions; however, field evidence collected in natural settings is less common. Furthermore, it is unknown whether precise pollen placement on the pollinator's body remains constant throughout the foraging period, or if such patterns become diffused over time (e.g. due to grooming). To test the prevalence of differential pollen placement in the wild, we examined a community of five night-blooming plant species in southern Thailand that share common bat pollinators. METHODS We mist-netted wild foraging nectar bats and collected pollen samples from four body parts: the crown of the head, face, chest and ventral side of one wing. We also noted the time of pollen collection to assess how pollinator pollen loads change throughout the foraging period. KEY RESULTS Our findings revealed that most of our plant study species placed pollen on precise areas of the bat, consistent with experimental work, and that patterns of differential pollen placement remained constant throughout the night. CONCLUSIONS This study demonstrates how diverse floral morphologies effectively limit interspecific pollen transfer among Old World bat-pollinated plants under natural conditions. Additionally, interspecific pollen transfer is probably minimal throughout the entire foraging period, since patterns of pollen on the bats' bodies were consistent over time.
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Affiliation(s)
- Alyssa B Stewart
- Department of Plant Science, Faculty of Science, Mahidol University, Bangkok 10400, Thailand
- Department of Biology, University of Maryland, College Park, MD 20742, USA
| | - Michele R Dudash
- Department of Biology, University of Maryland, College Park, MD 20742, USA
- Department of Natural Resource Management, South Dakota State University, Brookings, SD 57007, USA
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Zhou J, Dudash MR, Fenster CB, Zimmer EA. Development of highly variable microsatellite markers for the tetraploid Silene stellata (Caryophyllaceae). Appl Plant Sci 2016; 4:apps1600117. [PMID: 28101439 PMCID: PMC5238704 DOI: 10.3732/apps.1600117] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/19/2016] [Accepted: 10/27/2016] [Indexed: 05/14/2023]
Abstract
PREMISE OF THE STUDY We designed and tested microsatellite markers for the North American native species Silene stellata (Caryophyllaceae) to investigate its population genetic structure and identify selection on floral design through male reproductive success. METHODS AND RESULTS A total of 153 candidate microsatellite loci were isolated based on next-generation sequencing. We identified 18 polymorphic microsatellite loci in three populations of S. stellata, with di- or trinucleotide repeats. Genotyping results showed the number of alleles per locus ranged from six to 45 and expected heterozygosity ranged from 0.511 to 0.951. Five of these loci were successfully amplified in S. virginica and S. caroliniana and were also polymorphic. CONCLUSIONS The microsatellite markers reported here provide a valuable tool for paternity analysis in S. stellata. They will also be useful for investigating the population genetic structures of S. stellata and related species.
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Affiliation(s)
- Juannan Zhou
- Behavior, Ecology, Evolution and Systematics Graduate Program, University of Maryland, College Park, Maryland 20742 USA
- Department of Botany, National Museum of Natural History, MRC 166, Smithsonian Institution, Washington, DC 20013-7012 USA
- Author for correspondence:
| | - Michele R. Dudash
- Department of Natural Resource Management, South Dakota State University, Brookings, South Dakota 57007 USA
| | - Charles B. Fenster
- Department of Biology and Microbiology, South Dakota State University, Brookings, South Dakota 57007 USA
| | - Elizabeth A. Zimmer
- Department of Botany, National Museum of Natural History, MRC 166, Smithsonian Institution, Washington, DC 20013-7012 USA
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Stewart AB, Dudash MR. Flower‐visiting bat species contribute unequally toward agricultural pollination ecosystem services in southern Thailand. Biotropica 2016. [DOI: 10.1111/btp.12401] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Alyssa B. Stewart
- Department of Biology University of Maryland College Park MD 20742 USA
- Department of Plant Science Faculty of Science Mahidol University Bangkok 10400 Thailand
| | - Michele R. Dudash
- Department of Biology University of Maryland College Park MD 20742 USA
- Department of Natural Resource Management South Dakota State University Brookings SD 57007 USA
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21
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Rushing CS, Marra PP, Dudash MR. Winter habitat quality but not long‐distance dispersal influences apparent reproductive success in a migratory bird. Ecology 2016; 97:1218-27. [DOI: 10.1890/15-1259.1] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Affiliation(s)
- Clark S. Rushing
- Migratory Bird Center Smithsonian Conservation Biology Institute National Zoological Park Washington D.C. 20013 USA
- Graduate Program in Behavior, Ecology, Evolution, and Systematics Department of Biology University of Maryland College Park Maryland 20742 USA
| | - Peter P. Marra
- Migratory Bird Center Smithsonian Conservation Biology Institute National Zoological Park Washington D.C. 20013 USA
| | - Michele R. Dudash
- Graduate Program in Behavior, Ecology, Evolution, and Systematics Department of Biology University of Maryland College Park Maryland 20742 USA
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22
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Rushing CS, Marra PP, Dudash MR. Winter habitat quality but not long-distance breeding dispersal influences apparent reproductive success in a migratory bird. Ecology 2016. [DOI: 10.1890/15-1259] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Affiliation(s)
- Clark S. Rushing
- Migratory Bird Center, Smithsonian Conservation Biology Institute; National Zoological Park; Washington DC USA
- Graduate Program in Behavior, Ecology, Evolution, and Systematics, Department of Biology; University of Maryland; College Park MD USA
| | - Peter P. Marra
- Migratory Bird Center, Smithsonian Conservation Biology Institute; National Zoological Park; Washington DC USA
| | - Michele R. Dudash
- Graduate Program in Behavior, Ecology, Evolution, and Systematics, Department of Biology; University of Maryland; College Park MD USA
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Stewart AB, Dudash MR. Differential pollen placement on an Old World nectar bat increases pollination efficiency. Ann Bot 2016; 117:145-52. [PMID: 26482654 PMCID: PMC4701156 DOI: 10.1093/aob/mcv163] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/31/2015] [Accepted: 09/04/2015] [Indexed: 05/05/2023]
Abstract
BACKGROUND AND AIMS Plant species that share pollinators are potentially subject to non-adaptive interspecific pollen transfer, resulting in reduced reproductive success. Mechanisms that increase pollination efficiency between conspecific individuals are therefore highly beneficial. Many nocturnally flowering plant species in Thailand are pollinated by the nectar bat Eonycteris spelaea (Pteropodidae). This study tested the hypothesis that plant species within a community reduce interspecific pollen movement by placing pollen on different areas of the bat's body. METHODS Using flight cage trials, pollen transfer by E. spelaea was compared between conspecific versus heterospecific flowers across four bat-pollinated plant genera. Pollen from four locations on the bat's body was also quantified to determine if pollen placement varies by plant species. KEY RESULTS It was found that E. spelaea transfers significantly more pollen between conspecific than heterospecific flowers, and that diverse floral designs produce significantly different patterns of pollen deposition on E. spelaea. CONCLUSIONS In the Old World tropics, differential pollen placement is a mechanism that reduces competition among bat-pollinated plant species sharing a common pollinator.
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Affiliation(s)
- Alyssa B Stewart
- Department of Biology, University of Maryland, College Park, MD 20742, USA
| | - Michele R Dudash
- Department of Biology, University of Maryland, College Park, MD 20742, USA
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Barry KJ, Dudash MR. The importance of analyzing neighbor competitive response in the target-neighbor experimental design. Ecol Evol 2015; 5:5265-5271. [PMID: 30151129 PMCID: PMC6102521 DOI: 10.1002/ece3.1689] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2015] [Revised: 07/31/2015] [Accepted: 08/05/2015] [Indexed: 12/03/2022] Open
Abstract
The role of competition in community structure and species interactions is universal. However, how one quantifies the outcome of competitive interactions is frequently debated. Here, we review the strengths and weaknesses of the target-neighbor design, a type of additive design where one of the competing species is reduced to a single individual and where controls and analyses are used for the target, but not for the neighbors. We conducted a literature review to determine how the target-neighbor design has been typically used and analyzed. We found that historically, targets were often smaller than neighbors and introduced after neighbor establishment; thus, targets would have little effect on neighbors. However, as co-establishment of targets and neighbors of similar size is now common, the target is more likely to affect the neighbors than in its earlier usage. This can be problematic, because if targets have a significant effect on neighbor performance, bias is introduced into the assessment of the target results. As target treatment controls are necessary to determine the absolute effect of neighbors on target growth, we advocate that analysis of the neighbor competitive response serves as a necessary control for unexpected target x neighbor interactions.
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Affiliation(s)
- Kevin J. Barry
- Department of BiologyUniversity of MarylandCollege ParkMaryland20742
- Department of BiologyWest Virginia UniversityMorgantownWest Virginia26506
| | - Michele R. Dudash
- Department of BiologyUniversity of MarylandCollege ParkMaryland20742
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Rushing CS, Dudash MR, Marra PP. Habitat features and long-distance dispersal modify the use of social information by a long-distance migratory bird. J Anim Ecol 2015; 84:1469-79. [PMID: 26061822 DOI: 10.1111/1365-2656.12395] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2015] [Accepted: 05/04/2015] [Indexed: 11/28/2022]
Abstract
The processes by which individuals select breeding sites have important consequences for individual tness as well as population- and community-dynamics. Although there is increasing evidence that many animal species use information acquired from conspecics to assess the suitability of potential breeding sites, little is known about how the use of this social information is modified by biotic and abiotic conditions. We used an automated playback experiment to simulate two types of social information, post-breeding public information and pre-breeding location cues, to determine the relative importance of these cues for breeding site selection by a migratory songbird, the American redstart (Setophaga ruticilla). In addition, we used stable hydrogen isotopes to determine the dispersal status of individuals that responded to our experimental treatments and quantify whether long-distance dispersers use different social cues to select breeding sites compared to philopatric individuals. We found that points that received pre-breeding location cue treatments were signi cantly more likely to be settled by redstarts than control points that received no playback. However, we found no evidence the redstarts used post-breeding public information gathered during one season to select breeding sites the following year. Breeding site habitat structure was also a strong predictor of settlement probability, indicating that redstarts modi ed the use of social information based on habitat cues. Furthermore, stable hydrogen isotope signatures from individuals that responded to location cue treatments suggest that long-distance dispersers may rely more heavily on these cues than local recruits. Collectively, these results indicate that redstarts use multiple sources of information to select breeding sites, which could buffer individuals from selecting suboptimal sites when they breed in unfamiliar locations or when habitat quality becomes decoupled from social cues.
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Affiliation(s)
- Clark S Rushing
- Graduate Program in Behavior, Ecology, Evolution, and Systematics 2101 Bioscience Research Building, University of Maryland, College Park, MD 20742, USA.,Migratory Bird Center, Smithsonian Conservation Biology Institute, National Zoological Park, PO Box 37012 MRC 5503, Washington, DC 20013-7012, USA
| | - Michele R Dudash
- Graduate Program in Behavior, Ecology, Evolution, and Systematics 2101 Bioscience Research Building, University of Maryland, College Park, MD 20742, USA
| | - Peter P Marra
- Migratory Bird Center, Smithsonian Conservation Biology Institute, National Zoological Park, PO Box 37012 MRC 5503, Washington, DC 20013-7012, USA
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26
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Fenster CB, Reynolds RJ, Williams CW, Makowsky R, Dudash MR. Quantifying hummingbird preference for floral trait combinations: The role of selection on trait interactions in the evolution of pollination syndromes. Evolution 2015; 69:1113-27. [DOI: 10.1111/evo.12639] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2014] [Accepted: 02/18/2015] [Indexed: 11/28/2022]
Affiliation(s)
- Charles B. Fenster
- Department of Biology; University of Maryland, College Park; College Park Maryland 20742
- Mountain Lake Biological Station; 240 Salt Pond Road Pembroke Virginia 24136
| | - Richard J. Reynolds
- Department of Biology; University of Maryland, College Park; College Park Maryland 20742
- Mountain Lake Biological Station; 240 Salt Pond Road Pembroke Virginia 24136
- Division of Clinical Immunology and Rheumatology, Department of Medicine; University of Alabama at Birmingham
| | - Christopher W. Williams
- Mountain Lake Biological Station; 240 Salt Pond Road Pembroke Virginia 24136
- Frostburg State University; Frostburg Maryland 21502
- National Institutes of Health, NIDDK; Bethesda Maryland 20892
| | | | - Michele R. Dudash
- Department of Biology; University of Maryland, College Park; College Park Maryland 20742
- Mountain Lake Biological Station; 240 Salt Pond Road Pembroke Virginia 24136
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27
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Kula AAR, Castillo DM, Dudash MR, Fenster CB. Interactions between a pollinating seed predator and its host plant: the role of environmental context within a population. Ecol Evol 2014; 4:2901-12. [PMID: 25165527 PMCID: PMC4130447 DOI: 10.1002/ece3.1134] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2014] [Accepted: 04/30/2014] [Indexed: 11/09/2022] Open
Abstract
Plant-insect interactions often are important for plant reproduction, but the outcome of these interactions may vary with environmental context. Pollinating seed predators have positive and negative effects on host plant reproduction, and the interaction outcome is predicted to vary with density or abundance of the partners. We studied the interaction between Silene stellata, an herbaceous perennial, and Hadena ectypa, its specialized pollinating seed predator. Silene stellata is only facultatively dependent upon H. ectypa for pollination because other nocturnal moth co-pollinators are equally effective at pollen transfer. We hypothesized that for plants without conspecific neighbors, H. ectypa would have higher visitation rates compared to co-pollinators, and the plants would experience lower levels of H. ectypa pollen deposition. We predicted similar oviposition throughout the study site but greater H. ectypa predation in the area without conspecific neighbors compared to plants embedded in a naturally high density area. We found that H. ectypa had consistently higher visitation than moth co-pollinators in all host plant contexts. However, H. ectypa pollinator importance declined in areas with low conspecific density because of reduced pollen deposition, resulting in lower seed set. Conversely, oviposition was similar across the study site independent of host plant density. Greater likelihood of very high fruit predation combined with lower pollination by H. ectypa resulted in reduced S. stellata female reproductive success in areas with low conspecific density. Our results demonstrate local context dependency of the outcomes of pollinating seed predator interactions with conspecific host plant density within a population.
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Affiliation(s)
- Abigail A R Kula
- Department of Biology, University of Maryland College Park, Maryland, 20742 ; Mountain Lake Biological Station Pembroke, Virginia, 24136
| | - Dean M Castillo
- Mountain Lake Biological Station Pembroke, Virginia, 24136 ; Department of Biology, Indiana University Bloomington, Indiana, 47405
| | - Michele R Dudash
- Department of Biology, University of Maryland College Park, Maryland, 20742 ; Mountain Lake Biological Station Pembroke, Virginia, 24136
| | - Charles B Fenster
- Department of Biology, University of Maryland College Park, Maryland, 20742 ; Mountain Lake Biological Station Pembroke, Virginia, 24136
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Kula AAR, Dudash MR, Fenster CB. Choices and consequences of oviposition by a pollinating seed predator, Hadena ectypa (Noctuidae), on its host plant, Silene stellata (Caryophyllaceae). Am J Bot 2013; 100:1148-54. [PMID: 23720431 DOI: 10.3732/ajb.1200636] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
PREMISE OF THE STUDY Pollinating seed predators are models for the study of mutualisms. These insects have dual effects on host-plant fitness, through pollination as adults and flower and fruit predation as larvae. A rarely examined question is whether pollinating seed-predator oviposition choices are influenced by plant floral and size traits and the potential consequences of oviposition for host-plant reproduction. • METHODS We quantified oviposition by a pollinating seed predator, Hadena ectypa, on its host, Silene stellata, to determine if oviposition was associated with specific plant traits and whether oviposition was significantly correlated with fruit initiation or flower and fruit predation over three years. We also quantified whether stigmatic pollen loads of flowers visited by Hadena that both fed on nectar and oviposited were greater than when Hadena only fed on nectar. • KEY RESULTS Hadena had significant preference for plants having flowers with long corolla tubes in all three years. Moth oviposition was correlated with other traits only in some years. Oviposition did not increase stigmatic pollen loads. We observed significant positive relationships between both oviposition and fruit initiation and oviposition and flower/fruit predation. • CONCLUSIONS Hadena ectypa oviposition choices were based consistently on floral tube length differences among individuals, and the consequences of oviposition include both fruit initiation (due to pollination while feeding on nectar prior to oviposition) and larval flower/fruit predation. The positive association between oviposition and fruit initiation may explain the long-term maintenance of facultative pollinating seed-predator interactions.
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Affiliation(s)
- Abigail A R Kula
- Behavior, Ecology, Evolution and Systematics Graduate Program, University of Maryland, College Park, MD 20742, USA.
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Abstract
BACKGROUND AND AIMS Since the early 1990s, research on genetic variation of phenotypic plasticity has expanded and empirical research has emphasized the role of the environment on the expression of inbreeding depression. An emerging question is how these two evolutionary ecology mechanisms interact in novel environments. Interest in this area has grown with the need to understand the establishment of populations in response to climate change, and to human-assisted transport to novel environments. METHODS We compare performance in the field of outcrossed (O) and inbred lines (S1, S2) from 20 maternal families from each of two native populations of Mimulus guttatus. The experiment was planted in California in each population's home site, in the other populations's home site, in a novel site within the native range of M. guttatus, and in a novel site within the non-native range in North America. The experiment included nearly 6500 individuals. Survival, sexual reproduction and above-ground biomass were examined in order to evaluate inbreeding depression, and stem diameter and plant height were examined in order to evaluate phenotypic plasticity. KEY RESULTS Across all field sites, approx. 36 % of plants survived to flowering. Inbreeding depression differed among sites and outcrossed offspring generally outperformed selfed offspring. However, in the native-novel site, self-progeny performed better or equally well as outcross progeny. Significant phenotypic plasticity and genetic variation in plasticity was detected in the two architectural traits measured. The absolute value of plasticity showed the most marked difference between home and non-native novel site or non-native-novel site. Evidence was detected for an interaction between inbreeding and plasticity for stem diameter. CONCLUSIONS The results demonstrate that during initial population establishment, both inbreeding depression and phenotypic plasticity vary among field sites, and may be an important response to environments outside a species' currently occupied range. However, the interaction between inbreeding and plasticity may be limited and environment-dependent.
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Affiliation(s)
- C J Murren
- Department of Biology, College of Charleston, Charleston, SC 29424, USA.
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Abstract
Fragmentation of animal and plant populations typically leads to genetic erosion and increased probability of extirpation. Although these effects can usually be reversed by re-establishing gene flow between population fragments, managers sometimes fail to do so due to fears of outbreeding depression (OD). Rapid development of OD is due primarily to adaptive differentiation from selection or fixation of chromosomal variants. Fixed chromosomal variants can be detected empirically. We used an extended form of the breeders' equation to predict the probability of OD due to adaptive differentiation between recently isolated population fragments as a function of intensity of selection, genetic diversity, effective population sizes, and generations of isolation. Empirical data indicated that populations in similar environments had not developed OD even after thousands of generations of isolation. To predict the probability of OD, we developed a decision tree that was based on the four variables from the breeders' equation, taxonomic status, and gene flow within the last 500 years. The predicted probability of OD in crosses between two populations is elevated when the populations have at least one of the following characteristics: are distinct species, have fixed chromosomal differences, exchanged no genes in the last 500 years, or inhabit different environments. Conversely, the predicted probability of OD in crosses between two populations of the same species is low for populations with the same karyotype, isolated for <500 years, and that occupy similar environments. In the former case, we recommend crossing be avoided or tried on a limited, experimental basis. In the latter case, crossing can be carried out with low probability of OD. We used crosses with known results to test the decision tree and found that it correctly identified cases where OD occurred. Current concerns about OD in recently fragmented populations are almost certainly excessive.
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Affiliation(s)
- Richard Frankham
- Department of Biological Sciences, Macquarie University, NSW 2109, Australia.
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Dudash MR, Hassler C, Stevens PM, Fenster CB. Experimental floral and inflorescence trait manipulations affect pollinator preference and function in a hummingbird-pollinated plant. Am J Bot 2011; 98:275-282. [PMID: 21613116 DOI: 10.3732/ajb.1000350] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
PREMISE OF THE STUDY Controversy is ongoing regarding the importance of pollinator-mediated selection as a source of observed patterns of floral diversity. Although increasing evidence exists of pollinator-mediated selection acting on female reproductive success, there is still limited understanding of pollinator-mediated selection on floral traits via male reproductive success. Here we quantify potential selection by the ruby-throated hummingbird, Archilochus colubris, on four floral traits of hermaphroditic Silene exerted through male floral function. METHODS In single trait manipulative experiments we quantified hummingbird visitation preference and/or fluorescent dye (a pollen analog) donation as a function of number of flowers displayed (inflorescence size), height of the floral display (inflorescence height), floral color, and corolla tube length. KEY RESULTS Hummingbirds preferred to visit larger floral displays and floral displays at greater height, likely representing a general pollinator preference for larger, more visible signals and/or greater rewards. In addition, hummingbirds preferred to visit red flowers, and male function was greater in flowers manipulated to have longer corolla tubes. CONCLUSIONS Selection pressures exerted by hummingbirds on S. virginica floral and inflorescence design through male reproductive success are consistent with the contemporary expression of floral traits of S. virginica relative to related Silene species with different pollinators, and they are consistent with the hummingbird syndrome of traits expressed by S. virginica.
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Affiliation(s)
- Michele R Dudash
- Department of Biology, University of Maryland, College Park, Maryland 20742, USA.
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Reynolds RJ, Dudash MR, Fenster CB. MULTIYEAR STUDY OF MULTIVARIATE LINEAR AND NONLINEAR PHENOTYPIC SELECTION ON FLORAL TRAITS OF HUMMINGBIRD-POLLINATEDSILENE VIRGINICA. Evolution 2010; 64:358-69. [DOI: 10.1111/j.1558-5646.2009.00805.x] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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Reynolds RJ, Westbrook MJ, Rohde AS, Cridland JM, Fenster CB, Dudash MR. Pollinator specialization and pollination syndromes of three related North AmericanSilene. Ecology 2009; 90:2077-87. [DOI: 10.1890/08-1141.1] [Citation(s) in RCA: 79] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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Affiliation(s)
- Charles B Fenster
- Mountain Lake Biological Station, University of Virginia, Pembroke, VA, 24136, USA
- Department of Biology, University of Maryland, College Park, MD, 20742, USA
| | - W Scott Armbruster
- School of Biological Sciences, University of Portsmouth, King Henry Building, Portsmouth, PO1 2DY, UK
- Institute of Arctic Biology, University of Alaska, Fairbanks, AK 99775, USA
- Department of Biology, Norwegian University of Science and Technology, N-7491 Trondheim, Norway
| | - Michele R Dudash
- Mountain Lake Biological Station, University of Virginia, Pembroke, VA, 24136, USA
- Department of Biology, University of Maryland, College Park, MD, 20742, USA
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Abstract
To better understand invasion dynamics, it is essential to determine the influence of genetics and ecology in species persistence in both native and nonnative habitats. One approach is to assess patterns of selection on floral and growth traits of individuals in both habitats. Mimulus guttatus (Phrymaceae) has a mixed mating system and grows under variable water conditions across its native and nonnative range in North America. Field investigations of patterns of selection of floral and plant size traits were conducted in two native and two nonnative populations. Field-collected seed was grown and crossed in the glasshouse using a paternal half-sib design. The resulting offspring were grown in saturated and dry-down low-water conditions and the same traits were measured in both environments. Patterns of selection varied across years in the native range. Nonnative populations exhibited selection for increased floral size, consistent with the hypothesis that selection favors larger size in nonnative habitats. In the glasshouse, we detected genetic variation for traits across population/treatment combinations. However, size hierarchy in the glasshouse was dependent on water conditions. Our results suggest that both variable selection pressures and local adaptation probably influence the persistence of both native and nonnative populations.
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Affiliation(s)
- Courtney J Murren
- Department of Biology, College of Charleston, Charleston, SC 29424,USA
| | - Cynthia C Chang
- Department of Ecology and Evolution, Yale University, New Haven, CT 06520, USA
- Department of Biology, University of Maryland, College Park, MD 20742, USA
| | - Michele R Dudash
- Department of Biology, University of Maryland, College Park, MD 20742, USA
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Burd M, Ashman TL, Campbell DR, Dudash MR, Johnston MO, Knight TM, Mazer SJ, Mitchell RJ, Steets JA, Vamosi JC. Ovule number per flower in a world of unpredictable pollination. Am J Bot 2009; 96:1159-1167. [PMID: 21628266 DOI: 10.3732/ajb.0800183] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
The number of ovules per flower varies over several orders of magnitude among angiosperms. Here we consider evidence that stochastic uncertainty in pollen receipt and ovule fertilization has been a selective factor in the evolution of ovule number per flower. We hypothesize that stochastic variation in floral mating success creates an advantage to producing many ovules per flower because a plant will often gain more fitness from occasional abundant seed production in randomly successful flowers than it loses in resource commitment to less successful flowers. Greater statistical dispersion in pollination and fertilization among flowers increases the frequency of windfall success, which should increase the strength of selection for greater ovule number per flower. We therefore looked for evidence of a positive relationship between ovule number per flower and the statistical dispersion of pollen receipt or seed number per flower in a comparative analysis involving 187 angiosperm species. We found strong evidence of such a relationship. Our results support the hypothesis that unpredictable variation in mating success at the floral level has been a factor in the evolution of ovule packaging in angiosperms.
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Affiliation(s)
- Martin Burd
- School of Biological Sciences, Monash University, Melbourne, Victoria 3800, Australia
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Fenster CB, Cheely G, Dudash MR, Reynolds RJ. Nectar reward and advertisement in hummingbird-pollinated Silene virginica (Caryophyllaceae). Am J Bot 2006; 93:1800-1807. [PMID: 21642126 DOI: 10.3732/ajb.93.12.1800] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
We tested for an association between nectar and various floral traits and investigated their roles as primary and secondary pollinator attractants in hummingbird-pollinated Silene virginica. Our goal was to gain insight into the mechanisms of pollinator-mediated selection that underlies floral trait divergence within the genus. In a field population of S. virginica, we measured five floral and eight vegetative traits and quantified nectar volume, nectar sugar concentration, and total sugar reward (nectar volume × nectar sugar concentration). All three components of nectar reward were positively correlated to flower size, and nectar volume varied significantly among individuals within the population. To ascertain whether the correlation of specific floral traits with nectar reward influences the behavior of the primary pollinator of S. virginica, the ruby-throated hummingbird, Archilochus colubris, we investigated whether A. colubris preferred the expression of floral traits associated with high nectar volume and total sugar reward. We accomplished this by constructing floral arrays consisting of artificial flowers that had equal nectar quantity and total sugar reward but that differed in petal area and corolla tube diameter, which were positively correlated with nectar quantity and total sugar reward in our field study. In observations of visitation frequencies to the various floral-trait combinations, hummingbirds preferentially visited artificial floral phenotypes with larger petal displays, with the greatest preference for floral phenotypes with both larger petals and wider corolla-tube diameters. This association between primary and secondary floral attractants and hummingbird discrimination of floral features supports the concept that the floral traits of S. virginica reflect pollinator-mediated selection by the principal pollinator.
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Affiliation(s)
- Charles B Fenster
- Department of Biology, University of Maryland, College Park, Maryland 20742 USA; Mountain Lake Biological Station, Pembroke, Virginia 24136 USA; and Department of Biology, Amherst College, Amherst, Massachusetts 01002 USA
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Abstract
Low Ca/Mg ratios (a defining component of serpentine soils) and low water environmental conditions often co-occur in nature and are thought to exert strong selection pressures on natural populations. However, few studies test the individual and combined effects of these environmental factors. We investigated the effects of low Ca/Mg ratio and low water availability on plant leaf, stem, stolon, and floral traits of Mimulus guttatus, a bodenvag species, i.e., a species that occurs in serpentine and non-serpentine areas. We quantified genetic variation and genetic variation for plasticity for these leaf, stem, stolon, and floral traits at three hierarchical levels: field-habitat type, population, and family, and we evaluated the relative importance of local adaptation and plasticity. We chose two populations and 10 families per population from four distinct field "habitat types" in northern California: high Ca/Mg ratio (non-serpentine) and season-long water availability, high Ca/Mg ratio and seasonally drying, low Ca/Mg ratio (serpentine) and season-long water availability, and low Ca/Mg ratio and seasonally drying. Seedlings were planted into greenhouse treatments that mimicked the four field conditions. We only detected genetic variation for stem diameter and length of longest leaf at the field-habitat level, but we detected genetic variation at the family level for nearly all traits. Soil chemistry and water availability had strong phenotypic effects, alone and in combination. Our hypothesis of an association between responses to low water levels and low Ca/Mg ratio was upheld for length of longest leaf, stem diameter, corolla width, and total number of reproductive units, whereas for other traits, responses to Ca/Mg ratio and low water were clearly independent. Our results suggest that traits may evolve independently from Ca/Mg ratios and water availability and that our focal traits were not simple alternative measures of vigor. We found genetic variation for plasticity both at the field-habitat type and family levels for half of the traits studied. Phenotypic plasticity and genetic variation for plasticity appear to be more important than local adaptation in the success of these M. guttatus populations found across a heterogeneous landscape in northern California. Phenotypic plasticity is an important mechanism maintaining the broad ecological breadth of native populations of M. guttatus.
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Affiliation(s)
- Courtney J Murren
- Department of Biology, University of Maryland, College Park, Maryland 20742, USA.
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Kephart S, Reynolds RJ, Rutter MT, Fenster CB, Dudash MR. Pollination and seed predation by moths on Silene and allied Caryophyllaceae: evaluating a model system to study the evolution of mutualisms. New Phytol 2006; 169:667-80. [PMID: 16441748 DOI: 10.1111/j.1469-8137.2005.01619.x] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/06/2023]
Abstract
Nursery pollinators, and the plants they use as hosts for offspring development, function as exemplary models of coevolutionary mutualism. The two pre-eminent examples--fig wasps and yucca moths--show little variation in the interaction: the primary pollinator is an obligate mutualist. By contrast, nursery pollination of certain Caryophyllaceae, including Silene spp., by two nocturnal moth genera, Hadena and Perizoma, ranges from antagonistic to potentially mutualistic, offering an opportunity to test hypotheses about the factors that promote or discourage the evolution of mutualism. Here, we review nursery pollination and host-plant interactions in over 30 caryophyllaceous plants, based on published studies and a survey of researchers investigating pollination, seed predation, and moth morphology and behavior. We detected little direct evidence of mutualism in these moth-plant interactions, but found traits and patterns in both that are nonetheless consistent with the evolution of mutualism and merit further attention.
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Affiliation(s)
- Susan Kephart
- Department of Biology, Willamette University, Salem, OR 97301, USA.
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Knight TM, Steets JA, Vamosi JC, Mazer SJ, Burd M, Campbell DR, Dudash MR, Johnston MO, Mitchell RJ, Ashman TL. Pollen Limitation of Plant Reproduction: Pattern and Process. Annu Rev Ecol Evol Syst 2005. [DOI: 10.1146/annurev.ecolsys.36.102403.115320] [Citation(s) in RCA: 762] [Impact Index Per Article: 40.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Tiffany M. Knight
- National Center for Ecological Analysis and Synthesis, Santa Barbara, California 93101;
| | - Janette A. Steets
- Department of Biological Sciences, University of Pittsburgh, Pittsburgh, Pennsylvania 15260; ,
| | - Jana C. Vamosi
- Department of Biological Sciences, University of Calgary, Calgary, Alberta, Canada T2N 1N4;
| | - Susan J. Mazer
- Department of Ecology, Evolution and Marine Biology, University of California, Santa Barbara, California 93106;
| | - Martin Burd
- School of Biological Sciences, Monash University, Melbourne, Victoria 3800, Australia;
| | - Diane R. Campbell
- Department of Ecology and Evolutionary Biology, University of California, Irvine, California 92697;
| | - Michele R. Dudash
- Department of Biology, University of Maryland, College Park, Maryland 20742;
| | - Mark O. Johnston
- Department of Biology, Dalhousie University, Halifax, Nova Scotia, Canada B3H 4J1;
| | | | - Tia-Lynn Ashman
- Department of Biological Sciences, University of Pittsburgh, Pittsburgh, Pennsylvania 15260; ,
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Affiliation(s)
- Charles B. Fenster
- Department of Biology, University of Maryland, College Park, Maryland 20742;
| | - W. Scott Armbruster
- School of Biological Sciences, University of Portsmouth, Portsmouth, PO1 2DY, United Kingdom; Department of Biology, Norwegian University of Science and Technology, N-7491 Trondheim, Norway; Institute of Arctic Biology, University of Alaska, Fairbanks, Alaska 99775;
| | - Paul Wilson
- Department of Biology, California State University, Northridge, California 91330-8303;
| | - Michele R. Dudash
- Department of Biology, University of Maryland, College Park, Maryland 20742;
| | - James D. Thomson
- Department of Zoology, University of Toronto, Toronto, ON M5S 3G5;
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Ashman TL, Knight TM, Steets JA, Amarasekare P, Burd M, Campbell DR, Dudash MR, Johnston MO, Mazer SJ, Mitchell RJ, Morgan MT, Wilson WG. POLLEN LIMITATION OF PLANT REPRODUCTION: ECOLOGICAL AND EVOLUTIONARY CAUSES AND CONSEQUENCES. Ecology 2004. [DOI: 10.1890/03-8024] [Citation(s) in RCA: 850] [Impact Index Per Article: 42.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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Abstract
Predictions for the evolution of mating systems and genetic load vary, depending on the genetic basis of inbreeding depression (dominance versus overdominance, epistasis and the relative frequencies of genes of large and small effect). A distinction between the dominance and overdominance hypotheses is that deleterious recessive mutations should be purged in inbreeding populations. Comparative studies of populations differing in their level of inbreeding and experimental approaches that allow selection among inbred lines support this prediction. More direct biometric approaches provide strong support for the importance of partly recessive deleterious alleles. Investigators using molecular markers to study quantitative trait loci (QTL) often find support for overdominance, though pseudo-overdominance (deleterious alleles linked in repulsion) may bias this perception. QTL and biometric studies of inbred lines often find evidence for epistasis, which may also contribute to the perception of overdominance, though this may be because of the divergent lines initially crossed in QTL studies. Studies of marker segregation distortion commonly uncover genes of major effect on viability, but these have only minor contributions to inbreeding depression. Although considerable progress has been made in understanding the genetic basis of inbreeding depression, we feel that all three aspects merit more study in natural plant populations.
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Affiliation(s)
- David E Carr
- Blandy Experimental Farm, University of Virginia, 400 Blandy Farm Lane, Boyce, VA 22620, USA.
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Dudash MR, Fenster CB. The role of breeding system and inbreeding depression in the maintenance of an outcrossing mating strategy in Silene virginica (Caryophyllaceae). Am J Bot 2001; 88:1953-1959. [PMID: 21669628 DOI: 10.2307/3558422] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
The goal of this study was to understand the interaction among breeding system, mating system, and expression of inbreeding depression in the hermaphroditic, primarily hummingbird-pollinated, iteroparous, short-lived perennial Silene virginica. We performed hand-selfed and hand-outcrossed pollinations in the field, conducted detailed floral observations within individual flowers and plants, and assayed adult tissue from flowering plants for a genetic estimate of population outcrossing rate. We quantified the opportunity for geitonogamy as the proportion of days each plant exhibited simultaneous male and female function, i.e., asynchronous expression of male- and female-phased flowers. Expression of cumulative inbreeding depression based on germination rate and total flower production in the glasshouse was ∼40% and was congruent with the estimated high outcrossing rate of 0.89. Floral observations demonstrated strong temporal protandry within each flower (dichogamy) as well as complete spatial separation between male and female function within each flower (herkogamy). On average, 29% of the time there were both male- and female-phased flowers present on an individual plant. We conclude that our estimate of inbreeding depression is compatible with a largely outcrossing mating system and the amount of selfing observed, likely results from geitonogamy. This study illustrates the utility of examining both the causes and the consequences of inbreeding via selfing to provide additional insights into the evolution of plant mating systems.
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Affiliation(s)
- M R Dudash
- Department of Biology, H. J. Patterson Hall, University of Maryland, College Park, Maryland 20742 USA
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Carr DE, Dudash MR. The Effects of Five Generations of Enforced Selfing on Potential Male and Female Function in Mimulus guttatus. Evolution 1997. [DOI: 10.2307/2411002] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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Carr DE, Fenster CB, Dudash MR. The Relationship Between Mating-System Characters and Inbreeding Depression in Mimulus guttatus. Evolution 1997. [DOI: 10.2307/2411108] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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