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Montalvo LD, Kimball RT, Austin JD, Robinson SK. Unraveling the genomic landscape of Campylorhynchus wrens along western Ecuador's precipitation gradient: Insights into hybridization, isolation by distance, and isolation by the environment. Ecol Evol 2024; 14:e11661. [PMID: 38994212 PMCID: PMC11237350 DOI: 10.1002/ece3.11661] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2023] [Revised: 05/31/2024] [Accepted: 06/17/2024] [Indexed: 07/13/2024] Open
Abstract
Environmental gradients have the potential to influence genetic differentiation among populations ultimately leading to allopatric speciation. However, environmental gradients can also facilitate hybridization between closely related taxa. We investigated a putative hybrid zone in western Ecuador, involving two polytypic wren species (Aves: Troglodytidae), Campylorhynchus zonatus and C. fasciatus. Our study addressed two primary questions: (1) Is there evidence of population structure and genetic admixture between these taxa in western Ecuador? and (2) What are the relative contributions of isolation by distance and isolation by the environment to the observed genetic differentiation along the environmental gradient in this region? We analyzed 4409 single-nucleotide polymorphisms (SNPs) from 112 blood samples sequenced using ddRadSeq and a de novo assembly. The optimum number of genetic clusters ranged from 2 to 4, aligning with geographic origins, known phylogenetics, and physical or ecological constraints. We observed notable transitions in admixture proportions along the environmental gradient in western Ecuador between C. z. brevirostris and the northern and southern genetic clusters of C. f. pallescens. Genetic differentiation between the two C. f. pallescens populations could be attributed to an unreported potential physical barrier in central western Ecuador, where the proximity of the Andes to the coastline restricts lowland habitats, limiting dispersal and gene flow, especially among dry-habitat specialists. The observed admixture in C. f. pallescens suggests that this subspecies may be a hybrid between C. z. brevirostris and C. fasciatus, with varying degrees of admixture in western Ecuador and northwestern Peru. We found evidence of isolation by distance, while isolation by the environment was less pronounced but still significant for annual mean precipitation and precipitation seasonality. This study enhances our understanding of avian population genomics in tropical regions.
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Affiliation(s)
- Luis Daniel Montalvo
- Florida Museum of Natural History University of Florida Gainesville Florida USA
- Department of Biology University of Florida Gainesville Florida USA
| | | | - James D Austin
- Department of Wildlife Ecology and Conservation University of Florida Gainesville Florida USA
| | - Scott K Robinson
- Florida Museum of Natural History University of Florida Gainesville Florida USA
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2
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Contolini GM, Palkovacs EP. Intraspecific variation in a predator changes intertidal community through effects on a foundation species. Ecol Evol 2023; 13:e10131. [PMID: 37293122 PMCID: PMC10244894 DOI: 10.1002/ece3.10131] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2023] [Revised: 05/02/2023] [Accepted: 05/09/2023] [Indexed: 06/10/2023] Open
Abstract
Intraspecific variation is an important form of biodiversity that can alter community and ecosystem properties. Recent work demonstrates the community effects of intraspecific variation in predators via altering prey communities and in foundation species via shaping habitat attributes. However, tests of the community effects of intraspecific trait variation in predators acting on foundation species are lacking despite the fact that consumption of foundation species can have strong community effects by shaping habitat structure. Here, we tested the hypothesis that intraspecific foraging differences among populations of mussel-drilling dogwhelk predators (Nucella) differentially alter intertidal communities through effects on foundational mussels. We conducted a 9-month field experiment where we exposed intertidal mussel bed communities to predation from three Nucella populations that exhibit differences in size-selectivity and consumption time for mussel prey. At the end of the experiment, we measured mussel bed structure, species diversity, and community composition. While exposure to Nucella originating from different populations did not significantly alter overall community diversity, we found that differences in Nucella mussel selectivity significantly altered foundational mussel bed structure, which in turn altered the biomass of shore crabs and periwinkle snails. Our study extends the emerging paradigm of the ecological importance of intraspecific variation to include the effects of intraspecific variation on predators of foundation species.
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Affiliation(s)
- Gina M. Contolini
- Department of Ecology and Evolutionary BiologyUniversity of California Santa CruzSanta CruzCaliforniaUSA
| | - Eric P. Palkovacs
- Department of Ecology and Evolutionary BiologyUniversity of California Santa CruzSanta CruzCaliforniaUSA
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3
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Ectomycorrhizal fungal communities differ among parental and hybrid Populus cross types within a natural riparian habitat. FUNGAL ECOL 2021. [DOI: 10.1016/j.funeco.2021.101059] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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4
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Rushworth CA, Brandvain Y, Mitchell‐Olds T. Identifying the fitness consequences of sex in complex natural environments. Evol Lett 2020; 4:516-529. [PMID: 33312687 PMCID: PMC7719549 DOI: 10.1002/evl3.194] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2020] [Revised: 08/14/2020] [Accepted: 08/24/2020] [Indexed: 02/06/2023] Open
Abstract
In the natural world, sex prevails, despite its costs. Although much effort has been dedicated to identifying the intrinsic costs of sex (e.g., the cost of males), few studies have identified the ecological fitness consequences of sex. Furthermore, correlated biological traits that differ between sexuals and asexuals may alter these costs, or even render the typical costs of sex irrelevant. We conducted a large-scale, multisite, reciprocal transplant using multiple sexual and asexual genotypes of a native North American wildflower to show that sexual genotypes have reduced lifetime fitness, despite lower herbivory. We separated the effects of sex from those of hybridity, finding that overwinter survival is elevated in asexuals regardless of hybridity, but herbivores target hybrid asexuals more than nonhybrid asexual or sexual genotypes. Survival is lowest in homozygous sexual lineages, implicating inbreeding depression as a cost of sex. Our results show that the consequences of sex are shaped not just by sex itself, but by complex natural environments, correlated traits, and the identity and availability of mates.
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Affiliation(s)
- Catherine A. Rushworth
- Department of Evolution and EcologyUniversity of California, DavisDavisCalifornia95616
- University and Jepson HerbariaUniversity of California, BerkeleyBerkeleyCalifornia94720
- Department of Plant and Microbial BiologyUniversity of MinnesotaSt. PaulMinnesota55108
- Department of BiologyDuke UniversityDurhamNorth Carolina27708
| | - Yaniv Brandvain
- Department of Plant and Microbial BiologyUniversity of MinnesotaSt. PaulMinnesota55108
| | - Tom Mitchell‐Olds
- Department of BiologyDuke UniversityDurhamNorth Carolina27708
- Center for Genomic and Computational BiologyDuke UniversityDurhamNorth Carolina27708
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5
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Hultine KR, Allan GJ, Blasini D, Bothwell HM, Cadmus A, Cooper HF, Doughty CE, Gehring CA, Gitlin AR, Grady KC, Hull JB, Keith AR, Koepke DF, Markovchick L, Corbin Parker JM, Sankey TT, Whitham TG. Adaptive capacity in the foundation tree species Populus fremontii: implications for resilience to climate change and non-native species invasion in the American Southwest. CONSERVATION PHYSIOLOGY 2020; 8:coaa061. [PMID: 32685164 PMCID: PMC7359000 DOI: 10.1093/conphys/coaa061] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/21/2020] [Revised: 05/28/2020] [Accepted: 06/14/2020] [Indexed: 05/29/2023]
Abstract
Populus fremontii (Fremont cottonwood) is recognized as one of the most important foundation tree species in the southwestern USA and northern Mexico because of its ability to structure communities across multiple trophic levels, drive ecosystem processes and influence biodiversity via genetic-based functional trait variation. However, the areal extent of P. fremontii cover has declined dramatically over the last century due to the effects of surface water diversions, non-native species invasions and more recently climate change. Consequently, P. fremontii gallery forests are considered amongst the most threatened forest types in North America. In this paper, we unify four conceptual areas of genes to ecosystems research related to P. fremontii's capacity to survive or even thrive under current and future environmental conditions: (i) hydraulic function related to canopy thermal regulation during heat waves; (ii) mycorrhizal mutualists in relation to resiliency to climate change and invasion by the non-native tree/shrub, Tamarix; (iii) phenotypic plasticity as a mechanism for coping with rapid changes in climate; and (iv) hybridization between P. fremontii and other closely related Populus species where enhanced vigour of hybrids may preserve the foundational capacity of Populus in the face of environmental change. We also discuss opportunities to scale these conceptual areas from genes to the ecosystem level via remote sensing. We anticipate that the exploration of these conceptual areas of research will facilitate solutions to climate change with a foundation species that is recognized as being critically important for biodiversity conservation and could serve as a model for adaptive management of arid regions in the southwestern USA and around the world.
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Affiliation(s)
- Kevin R Hultine
- Department of Research, Conservation and Collections, Desert Botanical Garden, 1201 North Galvin Parkway, Phoenix, AZ 85008, USA
| | - Gerard J Allan
- Department of Biological Sciences and Merriam-Powell Center for Environmental Research, Northern Arizona University, 617 South Beaver Drive, Flagstaff, AZ 86011, USA
| | - Davis Blasini
- School of Life Sciences, Arizona State University, 427 East Tyler Mall, Tempe, AZ 85281, USA
| | - Helen M Bothwell
- Research School of Biology, Australian National University, 134 Linnaeus Way, Canberra ACT2601, Australia
| | - Abraham Cadmus
- Department of Biological Sciences and Merriam-Powell Center for Environmental Research, Northern Arizona University, 617 South Beaver Drive, Flagstaff, AZ 86011, USA
| | - Hillary F Cooper
- Department of Biological Sciences and Merriam-Powell Center for Environmental Research, Northern Arizona University, 617 South Beaver Drive, Flagstaff, AZ 86011, USA
| | - Chris E Doughty
- School of Informatics, Computing, and Cyber Systems, Northern Arizona University, 1295 South Knoles Drive, Flagstaff, AZ 86011, USA
| | - Catherine A Gehring
- Department of Biological Sciences and Merriam-Powell Center for Environmental Research, Northern Arizona University, 617 South Beaver Drive, Flagstaff, AZ 86011, USA
| | - Alicyn R Gitlin
- Sierra Club – Grand Canyon Chapter, 514 West Roosevelt Street, Phoenix, AZ 85003, USA
| | - Kevin C Grady
- School of Forestry, Northern Arizona University, East Pine Knoll Drive, Flagstaff, AZ 86011, USA
| | - Julia B Hull
- Department of Biological Sciences and Merriam-Powell Center for Environmental Research, Northern Arizona University, 617 South Beaver Drive, Flagstaff, AZ 86011, USA
| | - Arthur R Keith
- Department of Biological Sciences and Merriam-Powell Center for Environmental Research, Northern Arizona University, 617 South Beaver Drive, Flagstaff, AZ 86011, USA
| | - Dan F Koepke
- Department of Research, Conservation and Collections, Desert Botanical Garden, 1201 North Galvin Parkway, Phoenix, AZ 85008, USA
| | - Lisa Markovchick
- Department of Biological Sciences and Merriam-Powell Center for Environmental Research, Northern Arizona University, 617 South Beaver Drive, Flagstaff, AZ 86011, USA
| | - Jackie M Corbin Parker
- Department of Biological Sciences and Merriam-Powell Center for Environmental Research, Northern Arizona University, 617 South Beaver Drive, Flagstaff, AZ 86011, USA
| | - Temuulen T Sankey
- School of Informatics, Computing, and Cyber Systems, Northern Arizona University, 1295 South Knoles Drive, Flagstaff, AZ 86011, USA
| | - Thomas G Whitham
- Department of Biological Sciences and Merriam-Powell Center for Environmental Research, Northern Arizona University, 617 South Beaver Drive, Flagstaff, AZ 86011, USA
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6
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Mihaylova-Kroumova AB, Artiouchine I, Korenkov VD, Wagner GJ. Patterns of inheritance of acylsugar acyl groups in selected interspecific hybrids of genus Nicotiana. JOURNAL OF PLANT RESEARCH 2020; 133:509-523. [PMID: 32277383 DOI: 10.1007/s10265-020-01188-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/05/2019] [Accepted: 04/02/2020] [Indexed: 05/26/2023]
Abstract
Glandular trichomes on the surface of Solanaceae species produce acyl sugars that are species-, and cultivar-specific. Acyl sugars are known to possess insecticidal, antibiotic, and hormone-like properties, and as such have great potential as a class of naturally occurring pesticides and antibiotics. The objective of this work was to analyze the acyl composition of acyl sugars in the leaf trichome exudate from selected Nicotiana species and to follow the inheritance of acyl content in their hybrids. Trichome exudates were collected, and the acyl profiles of acyl sugars were identified via GC-MS. The variations in acyl group inheritance in the hybrids (a single parent resemblance, missing, complementary, and novel groups) matched the patterns described in the literature for a variety of secondary metabolites. However, we did not find a complementation of major parental acyl groups. Instead, in some hybrids we observed a dynamic change in the proportions of acyl groups, distinguishing the acyl group profiles as novel. We observed paternal (i.e. N. tabacum cv. Turkish Samsun × N. benthamiana hybrids) and maternal (i.e. N. tabacum cv. Samsun-nn × N. otophora) inheritance patterns, novel acyl profiles (N. excelsior hybrids), and missing acyl groups (N. excelsiana). Selective inheritance of some acyl groups in the hybrids of N. benthamiana (4- and 5-methylheptanoic isomers) or N. alata (octanoate) was found. Suggestions are given to explain certain patterns of inheritance. The data presented here contribute to the body of knowledge about the effect of interspecific hybridization on the secondary metabolites by including acylsugar acyl groups that have not been studied previously.
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Affiliation(s)
- Antoaneta B Mihaylova-Kroumova
- Kentucky Tobacco Research and Development Center, College of Agriculture, University of Kentucky, 1401 University Dr., Lexington, KY, 40546-0236, USA.
| | - Ivan Artiouchine
- Kentucky Tobacco Research and Development Center, College of Agriculture, University of Kentucky, 1401 University Dr., Lexington, KY, 40546-0236, USA
| | - Victor D Korenkov
- Kentucky Tobacco Research and Development Center, College of Agriculture, University of Kentucky, 1401 University Dr., Lexington, KY, 40546-0236, USA
| | - George J Wagner
- Kentucky Tobacco Research and Development Center, College of Agriculture, University of Kentucky, 1401 University Dr., Lexington, KY, 40546-0236, USA
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7
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Arraiano-Castilho R, Bidartondo M, Niskanen T, Zimmermann S, Frey B, Brunner I, Senn-Irlet B, Hörandl E, Gramlich S, Suz L. Plant-fungal interactions in hybrid zones: Ectomycorrhizal communities of willows (Salix) in an alpine glacier forefield. FUNGAL ECOL 2020. [DOI: 10.1016/j.funeco.2020.100936] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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8
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Selmants PC, Schweitzer JA, Adair KL, Holeski LM, Lindroth RL, Hart SC, Whitham TG. Genetic variation in tree leaf chemistry predicts the abundance and activity of autotrophic soil microorganisms. Ecosphere 2019. [DOI: 10.1002/ecs2.2795] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Affiliation(s)
- Paul C. Selmants
- U.S. Geological Survey Western Geographic Science Center Menlo Park California USA
| | - Jennifer A. Schweitzer
- Department of Ecology and Evolutionary Biology University of Tennessee Knoxville Tennessee USA
| | - Karen L. Adair
- Institute of Ecology and Evolution University of Oregon Eugene Oregon USA
| | - Liza M. Holeski
- Department of Biological Sciences Northern Arizona University Flagstaff Arizona USA
| | - Richard L. Lindroth
- Department of Entomology University of Wisconsin‐Madison Madison Wisconsin USA
| | - Stephen C. Hart
- Department of Life & Environmental Sciences Sierra Nevada Research Institute University of California Merced California USA
| | - Thomas G. Whitham
- Department of Biological Sciences Northern Arizona University Flagstaff Arizona USA
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9
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Mable BK. Conservation of adaptive potential and functional diversity: integrating old and new approaches. CONSERV GENET 2018. [DOI: 10.1007/s10592-018-1129-9] [Citation(s) in RCA: 52] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
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10
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Axelsson EP, Senior JK. The extended consequences of genetic conductivity: Mating distance affects community phenotypes in Norway spruce. Ecol Evol 2018; 8:11645-11655. [PMID: 30598763 PMCID: PMC6303695 DOI: 10.1002/ece3.4616] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2018] [Revised: 08/24/2018] [Accepted: 08/28/2018] [Indexed: 11/11/2022] Open
Abstract
Anthropogenic landscape-level alterations such as habitat fragmentation and long distance translocation of genetic material are currently altering the genetic connectivity and structure of forest tree populations globally. As the susceptibility of individual trees to dependent organisms is often genetically determined, it is possible that these genetic changes may extend beyond individuals to affect associated communities. To test this, we examined how variation in crossing distance among the progeny of 18 controlled crosses of Norway spruce (Picea abies) populations occurring across central Sweden affected chemical defense, and subsequently, a small community of galling Adelges aphids infecting planted trees at two common garden trails. Although crossing distance did not influence growth, vitality or reproduction in the studied population, it did influence the expression of one candidate defensive chemical compound, apigenin, which was found in higher concentrations within outcrossed trees. We also show that this variation in apigenin induced by crossing distance correlated with susceptibility to one member of the galling community but not the other. Furthermore, the effect of crossing distance on galling communities and the general susceptibility of Norway spruce to infection also varied with environment. Specifically, in the more benign environment, inbred trees suffered greater gall infection than outcrossed trees, which is contrary to general predictions that the effects of inbreeding should be more pronounced in harsher environments. These findings suggest that the effects of variation in crossing distance in forest trees can extend beyond the individual to influence whole communities.
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Affiliation(s)
- Erik Petter Axelsson
- Department of Wildlife, Fish and Environmental StudiesSwedish University of Agricultural SciencesSkogsmarksgrändUmeå
| | - John Keith Senior
- Department of Wildlife, Fish and Environmental StudiesSwedish University of Agricultural SciencesSkogsmarksgrändUmeå
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11
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Woolbright SA, Rehill BJ, Lindroth RL, DiFazio SP, Martinsen GD, Zinkgraf MS, Allan GJ, Keim P, Whitham TG. Large effect quantitative trait loci for salicinoid phenolic glycosides in Populus: Implications for gene discovery. Ecol Evol 2018; 8:3726-3737. [PMID: 29686853 PMCID: PMC5901179 DOI: 10.1002/ece3.3932] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2017] [Revised: 01/11/2018] [Accepted: 01/23/2018] [Indexed: 01/01/2023] Open
Abstract
Genomic studies have been used to identify genes underlying many important plant secondary metabolic pathways. However, genes for salicinoid phenolic glycosides (SPGs)—ecologically important compounds with significant commercial, cultural, and medicinal applications—remain largely undescribed. We used a linkage map derived from a full‐sib population of hybrid cottonwoods (Populus spp.) to search for quantitative trait loci (QTL) for the SPGs salicortin and HCH‐salicortin. SSR markers and primer sequences were used to anchor the map to the V3.0 P. trichocarpa genome. We discovered 21 QTL for the two traits, including a major QTL for HCH‐salicortin (R2 = .52) that colocated with a QTL for salicortin on chr12. Using the V3.0 Populus genome sequence, we identified 2,983 annotated genes and 1,480 genes of unknown function within our QTL intervals. We note ten candidate genes of interest, including a BAHD‐type acyltransferase that has been potentially linked to PopulusSPGs. Our results complement other recent studies in Populus with implications for gene discovery and the evolution of defensive chemistry in a model genus. To our knowledge, this is the first study to use a full‐sib mapping population to identify QTL intervals and gene lists associated with SPGs.
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Affiliation(s)
- Scott A Woolbright
- Department of Biology University of Arkansas at Little Rock Little Rock AR USA
| | - Brian J Rehill
- Department of Chemistry US Naval Academy Annapolis MD USA
| | | | | | - Gregory D Martinsen
- Environmental Genetics and Genomics Laboratory (EnGGen) Department of Biological Sciences Merriam-Powell Center for Environmental Research Northern Arizona University Flagstaff AZ USA
| | | | - Gerard J Allan
- Environmental Genetics and Genomics Laboratory (EnGGen) Department of Biological Sciences Merriam-Powell Center for Environmental Research Northern Arizona University Flagstaff AZ USA
| | - Paul Keim
- Department of Biological Sciences Pathogen and Microbe Institute Northern Arizona University Flagstaff AZ USA
| | - Thomas G Whitham
- Environmental Genetics and Genomics Laboratory (EnGGen) Department of Biological Sciences Merriam-Powell Center for Environmental Research Northern Arizona University Flagstaff AZ USA
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12
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Valencia-Cuevas L, Mussali-Galante P, Cano-Santana Z, Pujade-Villar J, Equihua-Martínez A, Tovar-Sánchez E. Genetic variation in foundation species governs the dynamics of trophic interactions. Curr Zool 2018; 64:13-22. [PMID: 29492034 PMCID: PMC5809035 DOI: 10.1093/cz/zox015] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2016] [Revised: 10/11/2016] [Accepted: 02/27/2017] [Indexed: 11/25/2022] Open
Abstract
Various studies have demonstrated that the foundation species genetic diversity can have direct effects that extend beyond the individual or population level, affecting the dependent communities. Additionally, these effects may be indirectly extended to higher trophic levels throughout the entire community. Quercus castanea is an oak species with characteristics of foundation species beyond presenting a wide geographical distribution and being a dominant element of Mexican temperate forests. In this study, we analyzed the influence of population (He) and individual (HL) genetic diversity of Q. castanea on its canopy endophagous insect community and associated parasitoids. Specifically, we studied the composition, richness (S) and density of leaf-mining moths (Lepidoptera: Tischeridae, Citheraniidae), gall-forming wasps (Hymenoptera: Cynipidae), and canopy parasitoids of Q. castanea. We sampled 120 trees belonging to six populations (20/site) through the previously recognized gradient of genetic diversity. In total, 22 endophagous insect species belonging to three orders (Hymenoptera, Lepidoptera, and Diptera) and 20 parasitoid species belonging to 13 families were identified. In general, we observed that the individual genetic diversity of the host plant (HL) has a significant positive effect on the S and density of the canopy endophagous insect communities. In contrast, He has a significant negative effect on the S of endophagous insects. Additionally, indirect effects of HL were observed, affecting the S and density of parasitoid insects. Our results suggest that genetic variation in foundation species can be one of the most important factors governing the dynamics of tritrophic interactions that involve oaks, herbivores, and parasitoids.
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Affiliation(s)
- Leticia Valencia-Cuevas
- Laboratorio de Marcadores Moleculares, Centro de Investigación en Biodiversidad y Conservación, Universidad Autónoma del Estado de Morelos, Av. Universidad 1001, Col. Chamilpa, Cuernavaca, Morelos, CP 62209, México
| | - Patricia Mussali-Galante
- Laboratorio de Investigaciones Ambientales, Centro de Investigación en Biotecnología, Universidad Autónoma del Estado de Morelos, Av. Universidad 1001, Col. Chamilpa, Cuernavaca, Morelos, CP 62209, México
| | - Zenón Cano-Santana
- Departamento de Ecología y Recursos Naturales, Facultad de Ciencias, Universidad Nacional Autónoma de México, Delegación Coyoacán, DF 04510, México
| | - Juli Pujade-Villar
- Departamento de Biología Animal, Universitat de Barcelona, Facultat de Biología, Av. Diagonal, 645, Barcelona 08028, España
| | | | - Efraín Tovar-Sánchez
- Laboratorio de Marcadores Moleculares, Centro de Investigación en Biodiversidad y Conservación, Universidad Autónoma del Estado de Morelos, Av. Universidad 1001, Col. Chamilpa, Cuernavaca, Morelos, CP 62209, México
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13
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Paffetti D, Travaglini D, Labriola M, Buonamici A, Bottalico F, Materassi A, Fasano G, Nocentini S, Vettori C. Land use and wind direction drive hybridization between cultivated poplar and native species in a Mediterranean floodplain environment. THE SCIENCE OF THE TOTAL ENVIRONMENT 2018; 610-611:1400-1412. [PMID: 28854483 DOI: 10.1016/j.scitotenv.2017.08.238] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/08/2017] [Revised: 08/22/2017] [Accepted: 08/22/2017] [Indexed: 06/07/2023]
Abstract
Deforestation and intensive land use management with plantations of fast-growing tree species, like Populus spp., may endanger native trees not only by eliminating or reducing their habitats, but also by diminishing their species integrity via hybridization and introgression. The genus Populus has persistent natural hybrids because clonal and sexual reproduction is common. The objective of this study was to assess the effect of land use management of poplar plantations on the spatial genetic structure and species composition in poplar stands. Specifically, we studied the potential breeding between natural and cultivated poplar populations in the Mediterranean environment to gain insight into spontaneous hybridization events between exotic and native poplars; we also used a GIS-based model to evaluate the potential threats related to an intensive land use management. Two study areas, both near to poplar plantations (P.×euramericana), were designated in the native mixed stands of P. alba, P. nigra and P.×canescens within protected areas. We found that the spatial genetic structure differed between the two stands and their differences depended on their environmental features. We detected a hybridization event with P.×canescens that was made possible by the synchrony of flowering between the poplar plantation and P.×canescens and facilitated by the wind intensity and direction favoring the spread of pollen. Taken together, our results indicate that natural and artificial barriers are crucial to mitigate the threats, and so they should be explicitly considered in land use planning. For example, our results suggest the importance of conserving rows of trees and shrubs along rivers and in agricultural landscapes. In sum, it is necessary to understand, evaluate, and monitor the spread of exotic species and genetic material to ensure effective land use management and mitigation of their impact on native tree populations.
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Affiliation(s)
- Donatella Paffetti
- Department of Agriculture, Food and Environmental Sciences, Agricultural Genetics Section, University of Florence, P.le delle Cascine 28, 50144 Florence, Italy.
| | - Davide Travaglini
- Department of Agricultural, Food and Forestry Systems, University of Florence, Via San Bonaventura 13, 50145, Florence, Italy.
| | - Mariaceleste Labriola
- Department of Agriculture, Food and Environmental Sciences, Agricultural Genetics Section, University of Florence, P.le delle Cascine 28, 50144 Florence, Italy; Institute of Bioscience and Bioresources (IBBR), National Research Council (CNR), Via Madonna del Piano 10, 50019 Sesto Fiorentino (FI), Italy.
| | - Anna Buonamici
- Institute of Bioscience and Bioresources (IBBR), National Research Council (CNR), Via Madonna del Piano 10, 50019 Sesto Fiorentino (FI), Italy.
| | - Francesca Bottalico
- Department of Agricultural, Food and Forestry Systems, University of Florence, Via San Bonaventura 13, 50145, Florence, Italy.
| | - Alessandro Materassi
- Institute for Biometeorology (IBIMET), National Research Council (CNR), Via Caproni 8, 50145 Firenze, Italy.
| | - Gianni Fasano
- Institute for Biometeorology (IBIMET), National Research Council (CNR), Via Caproni 8, 50145 Firenze, Italy.
| | - Susanna Nocentini
- Department of Agricultural, Food and Forestry Systems, University of Florence, Via San Bonaventura 13, 50145, Florence, Italy.
| | - Cristina Vettori
- Institute of Bioscience and Bioresources (IBBR), National Research Council (CNR), Via Madonna del Piano 10, 50019 Sesto Fiorentino (FI), Italy.
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14
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Segraves KA. The effects of genome duplications in a community context. THE NEW PHYTOLOGIST 2017; 215:57-69. [PMID: 28418074 DOI: 10.1111/nph.14564] [Citation(s) in RCA: 47] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/05/2016] [Accepted: 02/16/2017] [Indexed: 06/07/2023]
Abstract
Contents 57 I. 57 II. 59 III. 59 IV. 63 V. 64 VI. 64 VII. 66 66 References 66 SUMMARY: Whole-genome duplication (WGD), or polyploidy, has important effects on the genotype and phenotype of plants, potentially altering ecological interactions with other organisms. Even though the connections between polyploidy and species interactions have been recognized for some time, we are only just beginning to test whether WGD affects community context. Here I review the sparse information on polyploidy and community context and then present a set of hypotheses for future work. Thus far, community-level studies of polyploids suggest an array of outcomes, from no changes in community context to shifts in the abundance and composition of interacting species. I propose a number of mechanisms for how WGD could alter community context and how the emergence of polyploids in populations could also alter the community context of parental diploids and other plant species. Resolving how and when these changes are expected to occur will require a deeper understanding of the connections among WGD, phenotypic changes, and the direct and indirect effects of species interactions.
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Affiliation(s)
- Kari A Segraves
- Department of Biology, Syracuse University, Syracuse, NY, 13244, USA
- Archbold Biological Station, Venus, FL, 33960, USA
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Jarvis KJ, Allan GJ, Craig AJ, Beresic-Perrins RK, Wimp G, Gehring CA, Whitham TG. Arthropod communities on hybrid and parental cottonwoods are phylogenetically structured by tree type: Implications for conservation of biodiversity in plant hybrid zones. Ecol Evol 2017; 7:5909-5921. [PMID: 28808554 PMCID: PMC5551273 DOI: 10.1002/ece3.3146] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2017] [Accepted: 05/17/2017] [Indexed: 02/03/2023] Open
Abstract
Although hybridization in plants has been recognized as an important pathway in plant speciation, it may also affect the ecology and evolution of associated communities. Cottonwood species (Populus angustifolia and P. fremontii) and their naturally occurring hybrids are known to support different plant, animal, and microbial communities, but no studies have examined community structure within the context of phylogenetic history. Using a community composed of 199 arthropod species, we tested for differences in arthropod phylogenetic patterns within and among hybrid and parental tree types in a common garden. Three major patterns emerged. (1) Phylogenetic diversity (PD) was significantly different between arthropod communities on hybrids and Fremont cottonwood when pooled by tree type. (2) Mean phylogenetic distance (MPD) and net relatedness index (NRI) indicated that communities on hybrid trees were significantly more phylogenetically overdispersed than communities on either parental tree type. (3) Community distance (Dpw) indicated that communities on hybrids were significantly different than parental species. Our results show that arthropod communities on parental and hybrid cottonwoods exhibit significantly different patterns of phylogenetic structure. This suggests that arthropod community assembly is driven, in part, by plant-arthropod interactions at the level of cottonwood tree type. We discuss potential hypotheses to explain the effect of plant genetic dissimilarity on arthropod phylogenetic community structure, including the role of competition and environmental filtering. Our findings suggest that cottonwood species and their hybrids function as evolutionarily significant units (ESUs) that affect the assembly and composition of associated arthropod communities and deserve high priority for conservation.
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Affiliation(s)
- Karl J Jarvis
- School of Forestry Northern Arizona University Flagstaff AZ USA.,Biology Department Southern Utah University Cedar City UT USA
| | - Gerard J Allan
- Department of Biological Sciences Northern Arizona University Flagstaff AZ USA.,Merriam-Powell Center for Environmental Research Flagstaff AZ USA
| | - Ashley J Craig
- Department of Biological Sciences Northern Arizona University Flagstaff AZ USA
| | | | - Gina Wimp
- Department of Biology Georgetown University Washington DC USA
| | - Catherine A Gehring
- Department of Biological Sciences Northern Arizona University Flagstaff AZ USA.,Merriam-Powell Center for Environmental Research Flagstaff AZ USA
| | - Thomas G Whitham
- Department of Biological Sciences Northern Arizona University Flagstaff AZ USA.,Merriam-Powell Center for Environmental Research Flagstaff AZ USA
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Floate KD, Godbout J, Lau MK, Isabel N, Whitham TG. Plant-herbivore interactions in a trispecific hybrid swarm of Populus: assessing support for hypotheses of hybrid bridges, evolutionary novelty and genetic similarity. THE NEW PHYTOLOGIST 2016; 209:832-844. [PMID: 26346922 DOI: 10.1111/nph.13622] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/26/2015] [Accepted: 07/28/2015] [Indexed: 06/05/2023]
Abstract
UNLABELLED Natural systems of hybridizing plants are powerful tools with which to assess evolutionary processes between parental species and their associated arthropods. Here we report on these processes in a trispecific hybrid swarm of Populus trees. Using field observations, common garden experiments and genetic markers, we tested the hypothesis that genetic similarities among hosts underlie the distributions of 10 species of gall-forming arthropods and their ability to adapt to new host genotypes. KEY FINDINGS the degree of genetic relatedness among parental species determines whether hybridization is primarily bidirectional or unidirectional; host genotype and genetic similarity strongly affect the distributions of gall-forming species, individually and as a community. These effects were detected observationally in the wild and experimentally in common gardens; correlations between the diversity of host genotypes and their associated arthropods identify hybrid zones as centres of biodiversity and potential species interactions with important ecological and evolutionary consequences. These findings support both hybrid bridge and evolutionary novelty hypotheses. However, the lack of parallel genetic studies on gall-forming arthropods limits our ability to define the host of origin with their subsequent shift to other host species or their evolution on hybrids as their final destination.
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Affiliation(s)
- Kevin D Floate
- Agriculture and Agri-Food Canada, Lethbridge Research Centre, Lethbridge, Alberta, T1J 4B1, Canada
| | - Julie Godbout
- Natural Resources Canada, Canadian Forest Service, Laurentian Forestry Centre, Québec (Sainte-Foy), QC, G1V 4C7, Canada
| | - Matthew K Lau
- Merriam-Powell Center for Environmental Research and Department of Biological Sciences, Northern Arizona University, Flagstaff, AZ, 86011, USA
| | - Nathalie Isabel
- Natural Resources Canada, Canadian Forest Service, Laurentian Forestry Centre, Québec (Sainte-Foy), QC, G1V 4C7, Canada
| | - Thomas G Whitham
- Merriam-Powell Center for Environmental Research and Department of Biological Sciences, Northern Arizona University, Flagstaff, AZ, 86011, USA
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Gene Flow of a Forest-Dependent Bird across a Fragmented Landscape. PLoS One 2015; 10:e0140938. [PMID: 26580222 PMCID: PMC4651334 DOI: 10.1371/journal.pone.0140938] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2015] [Accepted: 09/30/2015] [Indexed: 02/01/2023] Open
Abstract
Habitat loss and fragmentation can affect the persistence of populations by reducing connectivity and restricting the ability of individuals to disperse across landscapes. Dispersal corridors promote population connectivity and therefore play important roles in maintaining gene flow in natural populations inhabiting fragmented landscapes. In the prairies, forests are restricted to riparian areas along river systems which act as important dispersal corridors for forest dependent species across large expanses of unsuitable grassland habitat. However, natural and anthropogenic barriers within riparian systems have fragmented these forested habitats. In this study, we used microsatellite markers to assess the fine-scale genetic structure of a forest-dependent species, the black-capped chickadee (Poecile atricapillus), along 10 different river systems in Southern Alberta. Using a landscape genetic approach, landscape features (e.g., land cover) were found to have a significant effect on patterns of genetic differentiation. Populations are genetically structured as a result of natural breaks in continuous habitat at small spatial scales, but the artificial barriers we tested do not appear to restrict gene flow. Dispersal between rivers is impeded by grasslands, evident from isolation of nearby populations (~ 50 km apart), but also within river systems by large treeless canyons (>100 km). Significant population genetic differentiation within some rivers corresponded with zones of different cottonwood (riparian poplar) tree species and their hybrids. This study illustrates the importance of considering the impacts of habitat fragmentation at small spatial scales as well as other ecological processes to gain a better understanding of how organisms respond to their environmental connectivity. Here, even in a common and widespread songbird with high dispersal potential, small breaks in continuous habitats strongly influenced the spatial patterns of genetic variation.
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Valencia-Cuevas L, Tovar-Sánchez E. Oak canopy arthropod communities: which factors shape its structure? REVISTA CHILENA DE HISTORIA NATURAL 2015. [DOI: 10.1186/s40693-015-0045-3] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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Caseys C, Stritt C, Glauser G, Blanchard T, Lexer C. Effects of hybridization and evolutionary constraints on secondary metabolites: the genetic architecture of phenylpropanoids in European populus species. PLoS One 2015; 10:e0128200. [PMID: 26010156 PMCID: PMC4444209 DOI: 10.1371/journal.pone.0128200] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2015] [Accepted: 04/24/2015] [Indexed: 12/18/2022] Open
Abstract
The mechanisms responsible for the origin, maintenance and evolution of plant secondary metabolite diversity remain largely unknown. Decades of phenotypic studies suggest hybridization as a key player in generating chemical diversity in plants. Knowledge of the genetic architecture and selective constraints of phytochemical traits is key to understanding the effects of hybridization on plant chemical diversity and ecological interactions. Using the European Populus species P. alba (White poplar) and P. tremula (European aspen) and their hybrids as a model, we examined levels of inter- and intraspecific variation, heritabilities, phenotypic correlations, and the genetic architecture of 38 compounds of the phenylpropanoid pathway measured by liquid chromatography and mass spectrometry (UHPLC-MS). We detected 41 quantitative trait loci (QTL) for chlorogenic acids, salicinoids and flavonoids by genetic mapping in natural hybrid crosses. We show that these three branches of the phenylpropanoid pathway exhibit different geographic patterns of variation, heritabilities, and genetic architectures, and that they are affected differently by hybridization and evolutionary constraints. Flavonoid abundances present high species specificity, clear geographic structure, and strong genetic determination, contrary to salicinoids and chlorogenic acids. Salicinoids, which represent important defence compounds in Salicaceae, exhibited pronounced genetic correlations on the QTL map. Our results suggest that interspecific phytochemical differentiation is concentrated in downstream sections of the phenylpropanoid pathway. In particular, our data point to glycosyltransferase enzymes as likely targets of rapid evolution and interspecific differentiation in the 'model forest tree' Populus.
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Affiliation(s)
- Celine Caseys
- Unit of Ecology and Evolution, Department of Biology, University of Fribourg, Fribourg, Switzerland
- Department of Botany and Biodiversity Research Centre, University of British Columbia, Vancouver, Canada
| | - Christoph Stritt
- Unit of Ecology and Evolution, Department of Biology, University of Fribourg, Fribourg, Switzerland
| | - Gaetan Glauser
- Neuchâtel Platform of Analytical Chemistry, Faculty of science, University of Neuchâtel, Neuchâtel, Switzerland
| | - Thierry Blanchard
- Unit of Ecology and Evolution, Department of Biology, University of Fribourg, Fribourg, Switzerland
| | - Christian Lexer
- Unit of Ecology and Evolution, Department of Biology, University of Fribourg, Fribourg, Switzerland
- Department of Botany and Biodiversity Research, University of Vienna, Vienna, Austria
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Tovar-Sánchez E, Valencia-Cuevas L, Mussali-Galante P, Ramírez-Rodríguez R, Castillo-Mendoza E. Effect of host-plant genetic diversity on oak canopy arthropod community structure in central Mexico. REVISTA CHILENA DE HISTORIA NATURAL 2015. [DOI: 10.1186/s40693-015-0042-6] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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Maldonado-López Y, Cuevas-Reyes P, González-Rodríguez A, Pérez-López G, Acosta-Gómez C, Oyama K. Relationships among plant genetics, phytochemistry and herbivory patterns in Quercus castanea across a fragmented landscape. Ecol Res 2014. [DOI: 10.1007/s11284-014-1218-2] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Wojtowicz T, Compson ZG, Lamit LJ, Whitham TG, Gehring CA. Plant genetic identity of foundation tree species and their hybrids affects a litter-dwelling generalist predator. Oecologia 2014; 176:799-810. [PMID: 25205028 DOI: 10.1007/s00442-014-2998-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2014] [Accepted: 06/09/2014] [Indexed: 12/01/2022]
Abstract
The effects of plant genetics on predators, especially those not living on the plant itself, are rarely studied and poorly understood. Therefore, we investigated the effect of plant hybridization and genotype on litter-dwelling spiders. Using an 18-year-old cottonwood common garden, we recorded agelenid sheet-web density associated with the litter layers of replicated genotypes of three tree cross types: Populus fremontii, Populus angustifolia, and their F1 hybrids. We surveyed 118 trees for agelenid litter webs at two distances from the trees (0-100 and 100-200 cm from trunk) and measured litter depth as a potential mechanism of web density patterns. Five major results emerged: web density within a 1-m radius of P. angustifolia was approximately three times higher than within a 1-m radius of P. fremontii, with F1 hybrids having intermediate densities; web density responded to P. angustifolia and F1 hybrid genotypes as indicated by a significant genotype × distance interaction, with some genotypes exhibiting a strong decline in web density with distance, while others did not; P. angustifolia litter layers were deeper than those of P. fremontii at both distance classes, and litter depth among P. angustifolia genotypes differed up to 300%; cross type and genotype influenced web density via their effects on litter depth, and these effects were influenced by distance; web density was more sensitive to the effects of tree cross type than genotype. By influencing generalist predators, plant hybridization and genotype may indirectly impact trophic interactions such as intraguild predation, possibly affecting trophic cascades and ecosystem processes.
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Affiliation(s)
- Todd Wojtowicz
- Department of Biological Sciences, Northern Arizona University, Flagstaff, AZ, 86011-5640, USA,
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Alexander HM, Emry DJ, Pace BA, Kost MA, Sparks KA, Mercer KL. Roles of maternal effects and nuclear genetic composition change across the life cycle of crop-wild hybrids. AMERICAN JOURNAL OF BOTANY 2014; 101:1176-1188. [PMID: 25016007 DOI: 10.3732/ajb.1400088] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
• Premise of the study: The fitness of an offspring may depend on its nuclear genetic composition (via both parental genotypes) as well as on genetic maternal effects (via only the maternal parent). Understanding the relative importance of these two genetic factors is particularly important for research on crop-wild hybridization, since traits with important genetic maternal effects (e.g., seed size) often differ among crops and their relatives. We hypothesized that the effects of these genetic factors on fitness components would change across the life cycle of hybrids.• Methods: We followed seed, plant size, and reproductive traits in field experiments with wild and four crop-wild hybrids of sunflower (Helianthus annuus), which differed in nuclear genetic composition and maternal parent (wild or F1 hybrid).• Key results: We identified strong genetic maternal effects for early life cycle characteristics, with seeds produced on an F1 mother having premature germination, negligible seed dormancy, and greater seedling size. Increased percentages of crop alleles also increased premature germination and reduced dormancy in seeds produced on a wild mother. For mature plants, nuclear genetic composition dominated: greater percentages of crop alleles reduced height, branching, and fecundity.• Conclusions: Particular backcrosses between hybrids and wilds may differentially facilitate movement of crop alleles into wild populations due to their specific features. For example, backcross seeds produced on wild mothers can persist in the seed bank, illustrating the importance of genetic maternal effects, whereas backcross individuals with either wild or F1 mothers have high fecundity, resulting from their wild-like nuclear genetic composition.
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Affiliation(s)
- Helen M Alexander
- Department of Ecology and Evolutionary Biology, University of Kansas, Lawrence, Kansas 66045 USA
| | - D Jason Emry
- Department of Biology, Washburn University, Topeka, Kansas 66621 USA
| | - Brian A Pace
- Department of Horticulture and Crop Science, Ohio State University, Columbus, Ohio 43210 USA
| | - Matthew A Kost
- Department of Horticulture and Crop Science, Ohio State University, Columbus, Ohio 43210 USA
| | - Kathryn A Sparks
- Department of Ecology and Evolutionary Biology, University of Kansas, Lawrence, Kansas 66045 USA
| | - Kristin L Mercer
- Department of Horticulture and Crop Science, Ohio State University, Columbus, Ohio 43210 USA
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Grant PR, Grant BR. Synergism of natural selection and introgression in the origin of a new species. Am Nat 2014; 183:671-81. [PMID: 24739199 DOI: 10.1086/675496] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
This article explores how introgressive hybridization enhances the evolutionary effects of natural selection and how, reciprocally, natural selection can enhance the evolutionary effects of introgression. Both types of interaction were observed during a 40-year study of Darwin's finches (Geospiza) on the small Galápagos island of Daphne Major. Hybrids, produced rarely by Geospiza fortis (medium ground finch) breeding with Geospiza scandens (cactus finch) and Geospiza fuliginosa (small ground finch), survived and bred as well as the parental species in the past 3 decades. By backcrossing, they increased the standing genetic variation and thereby the evolutionary responsiveness of the populations to natural selection. Natural selection occurred in droughts and oscillated in direction as a result of climatically induced fluctuations in food composition. Introgressive hybridization has led to the formation of a new lineage. It was initiated by a large, introgressed, hybrid male with a unique song and genetic marker that immigrated from the nearby island of Santa Cruz and bred with local hybrids and with G. fortis. All members of the lineage died in the 2003-2005 drought except a brother and a sister, who then bred with each other. Subsequent increase in the lineage was facilitated by selective mortality of the largest G. fortis. Breeding endogamously, the lineage is behaving as a biological species.
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Affiliation(s)
- Peter R Grant
- Department of Ecology and Evolutionary Biology, Princeton University, Princeton, New Jersey 08544
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LeBoldus JM, Isabel N, Floate KD, Blenis P, Thomas BR. Testing the 'hybrid susceptibility' and 'phenological sink' hypotheses using the P. balsamifera - P. deltoides hybrid zone and septoria leaf spot [Septoria musiva]. PLoS One 2013; 8:e84437. [PMID: 24386379 PMCID: PMC3874013 DOI: 10.1371/journal.pone.0084437] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2013] [Accepted: 11/15/2013] [Indexed: 11/19/2022] Open
Abstract
Hybrid genotypes that arise between plant species frequently have increased susceptibility to arthropod pests and fungal pathogens. This pattern has been attributed to the breakdown of plant defenses ('Hybrid susceptibility' hypothesis) and (or) to extended periods of susceptibility attributed to plant phenologies in zones of species overlap and (or) hybridization ('phenological sink' hypothesis). We examined these hypotheses by assessing the susceptibility of parental and hybrid Populus host genotypes to a leaf spot disease caused by the fungal pathogen Septoria musiva. For this purpose, 214 genotypes were obtained from morphologically pure zones of P. balsamifera and P. deltoides, and from an intervening zone of overlap and hybridization on the drainage of the Red Deer River, Alberta, Canada. Genotypes were identified as P. balsamifera, P. deltoides, or hybrid using a suite of 27 species-specific SNP markers. Initially the genetic structure of the hybrid zone was characterized with 27.7% of trees classified as admixed individuals. To test the hybrid susceptibility hypothesis, a subset of 52 genotypes was inoculated with four isolates of S. musiva. Levels of susceptibility were P. balsamifera > F1 hybrid > P. deltoides. A further 53 genotypes were grown in a common garden to assess the effect of genotype on variation in leaf phenology. Leaf phenology was more variable within the category of hybrid genotypes than within categories of either parental species. Leaf phenology was also more variable for the category of trees originating in the hybrid (P. balsamifera - P. deltoides [hybrid and parental genotypes combined]) zone than in adjacent pure zones of the parental species. The results from the inoculation experiment support the hybrid intermediacy hypothesis. The results from the common garden experiment support the 'phenological sink' hypothesis. These findings have greatly increased our understanding of the epidemiology and ecology of fungal pathogens in plant hybrid zones.
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Affiliation(s)
- Jared M. LeBoldus
- Department of Plant Pathology, North Dakota State University, Fargo, North Dakota, United States of America
| | - Nathalie Isabel
- Laurentian Forestry Centre, Canadian Forest Service, Natural Resources Canada, Sainte-Foy, Québec, Canada
| | - Kevin D. Floate
- Lethbridge Research Center, Agriculture and Agri-Food Canada, Lethbridge, Alberta, Canada
| | - Peter Blenis
- Department of Renewable Resources, University of Alberta, Edmonton, Alberta, Canada
| | - Barb R. Thomas
- Department of Renewable Resources, University of Alberta, Edmonton, Alberta, Canada
- Alberta-Pacific Forest Industries Inc., Boyle, Alberta, Canada
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Scriber JM. Climate-Driven Reshuffling of Species and Genes: Potential Conservation Roles for Species Translocations and Recombinant Hybrid Genotypes. INSECTS 2013; 5:1-61. [PMID: 26462579 PMCID: PMC4592632 DOI: 10.3390/insects5010001] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/11/2013] [Revised: 12/04/2013] [Accepted: 12/06/2013] [Indexed: 01/11/2023]
Abstract
Comprising 50%-75% of the world's fauna, insects are a prominent part of biodiversity in communities and ecosystems globally. Biodiversity across all levels of biological classifications is fundamentally based on genetic diversity. However, the integration of genomics and phylogenetics into conservation management may not be as rapid as climate change. The genetics of hybrid introgression as a source of novel variation for ecological divergence and evolutionary speciation (and resilience) may generate adaptive potential and diversity fast enough to respond to locally-altered environmental conditions. Major plant and herbivore hybrid zones with associated communities deserve conservation consideration. This review addresses functional genetics across multi-trophic-level interactions including "invasive species" in various ecosystems as they may become disrupted in different ways by rapid climate change. "Invasive genes" (into new species and populations) need to be recognized for their positive creative potential and addressed in conservation programs. "Genetic rescue" via hybrid translocations may provide needed adaptive flexibility for rapid adaptation to environmental change. While concerns persist for some conservationists, this review emphasizes the positive aspects of hybrids and hybridization. Specific implications of natural genetic introgression are addressed with a few examples from butterflies, including transgressive phenotypes and climate-driven homoploid recombinant hybrid speciation. Some specific examples illustrate these points using the swallowtail butterflies (Papilionidae) with their long-term historical data base (phylogeographical diversity changes) and recent (3-decade) climate-driven temporal and genetic divergence in recombinant homoploid hybrids and relatively recent hybrid speciation of Papilio appalachiensis in North America. Climate-induced "reshuffling" (recombinations) of species composition, genotypes, and genomes may become increasingly ecologically and evolutionarily predictable, but future conservation management programs are more likely to remain constrained by human behavior than by lack of academic knowledge.
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Affiliation(s)
- Jon Mark Scriber
- Department of Entomology, Michigan State University, East Lansing, Michigan, MI 48824, USA.
- McGuire Center for Lepidoptera and Biodiversity, Florida Museum of Natural History, University of Florida, Gainesville, FL 32611, USA.
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Wang ZH, Zhang D, Bai Y, Zhang YH, Liu Y, Wu Y, Lin XY, Wen JW, Xu CM, Li LF, Liu B. Genomewide variation in an introgression line of rice-Zizania revealed by whole-genome re-sequencing. PLoS One 2013; 8:e74479. [PMID: 24058573 PMCID: PMC3776793 DOI: 10.1371/journal.pone.0074479] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2013] [Accepted: 07/31/2013] [Indexed: 12/17/2022] Open
Abstract
BACKGROUND Hybridization between genetically diverged organisms is known as an important avenue that drives plant genome evolution. The possible outcomes of hybridization would be the occurrences of genetic instabilities in the resultant hybrids. It remained under-investigated however whether pollination by alien pollens of a closely related but sexually "incompatible" species could evoke genomic changes and to what extent it may result in phenotypic novelties in the derived progenies. METHODOLOGY/PRINCIPAL FINDINGS In this study, we have re-sequenced the genomes of Oryza sativa ssp. japonica cv. Matsumae and one of its derived introgressant RZ35 that was obtained from an introgressive hybridization between Matsumae and Zizanialatifolia Griseb. in general, 131 millions 90 base pair (bp) paired-end reads were generated which covered 13.2 and 21.9 folds of the Matsumae and RZ35 genomes, respectively. Relative to Matsumae, a total of 41,724 homozygous single nucleotide polymorphisms (SNPs) and 17,839 homozygous insertions/deletions (indels) were identified in RZ35, of which 3,797 SNPs were nonsynonymous mutations. Furthermore, rampant mobilization of transposable elements (TEs) was found in the RZ35 genome. The results of pathogen inoculation revealed that RZ35 exhibited enhanced resistance to blast relative to Matsumae. Notably, one nonsynonymous mutation was found in the known blast resistance gene Pid3/Pi25 and real-time quantitative (q) RT-PCR analysis revealed constitutive up-regulation of its expression, suggesting both altered function and expression of Pid3/Pi25 may be responsible for the enhanced resistance to rice blast by RZ35. CONCLUSIONS/SIGNIFICANCE Our results demonstrate that introgressive hybridization by Zizania has provoked genomewide, extensive genomic changes in the rice genome, and some of which have resulted in important phenotypic novelties. These findings suggest that introgressive hybridization by alien pollens of even a sexually incompatible species may represent a potent means to generate novel genetic diversities, and which may have played relevant roles in plant evolution and can be manipulated for crop improvements.
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Affiliation(s)
- Zhen-Hui Wang
- Key Laboratory of Molecular Epigenetics of Ministry of Education (MOE) and Institute of Genetics and Cytology, Northeast Normal University, Changchun, China
- Faculty of Agronomy, Jilin Agricultural University, Changchun, China
| | - Di Zhang
- Key Laboratory of Molecular Epigenetics of Ministry of Education (MOE) and Institute of Genetics and Cytology, Northeast Normal University, Changchun, China
| | - Yan Bai
- Key Laboratory of Molecular Epigenetics of Ministry of Education (MOE) and Institute of Genetics and Cytology, Northeast Normal University, Changchun, China
| | - Yun-Hong Zhang
- Key Laboratory of Molecular Epigenetics of Ministry of Education (MOE) and Institute of Genetics and Cytology, Northeast Normal University, Changchun, China
| | - Ying Liu
- Key Laboratory of Molecular Epigenetics of Ministry of Education (MOE) and Institute of Genetics and Cytology, Northeast Normal University, Changchun, China
| | - Ying Wu
- Key Laboratory of Molecular Epigenetics of Ministry of Education (MOE) and Institute of Genetics and Cytology, Northeast Normal University, Changchun, China
| | - Xiu-Yun Lin
- Jilin Academy of Agricultural Sciences, Changchun, China
| | - Jia-Wei Wen
- Jilin Academy of Agricultural Sciences, Changchun, China
| | - Chun-Ming Xu
- Key Laboratory of Molecular Epigenetics of Ministry of Education (MOE) and Institute of Genetics and Cytology, Northeast Normal University, Changchun, China
| | - Lin-Feng Li
- Key Laboratory of Molecular Epigenetics of Ministry of Education (MOE) and Institute of Genetics and Cytology, Northeast Normal University, Changchun, China
- * E-mail: (LL); (BL)
| | - Bao Liu
- Key Laboratory of Molecular Epigenetics of Ministry of Education (MOE) and Institute of Genetics and Cytology, Northeast Normal University, Changchun, China
- * E-mail: (LL); (BL)
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Soltis PS. Hybridization, speciation and novelty. J Evol Biol 2013; 26:291-3. [PMID: 23324011 DOI: 10.1111/jeb.12095] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2012] [Revised: 12/03/2012] [Accepted: 12/03/2012] [Indexed: 12/22/2022]
Affiliation(s)
- P S Soltis
- Florida Museum of Natural History, University of Florida, Gainesville, FL 32611-7800, USA.
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Whitehead SR, Bowers MD. Iridoid and secoiridoid glycosides in a hybrid complex of bush honeysuckles (Lonicera spp., Caprifolicaceae): implications for evolutionary ecology and invasion biology. PHYTOCHEMISTRY 2013; 86:57-63. [PMID: 23228598 DOI: 10.1016/j.phytochem.2012.10.012] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/30/2012] [Revised: 09/06/2012] [Accepted: 10/16/2012] [Indexed: 05/21/2023]
Abstract
Interspecific hybridization among non-native plant species can generate genotypes that are more reproductively successful in the introduced habitat than either parent. One important mechanism that may serve as a stimulus for the evolution of invasiveness in hybrids is increased variation in secondary metabolite chemistry, but still very little is known about patterns of chemical trait introgression in plant hybrid zones. This study examined the occurrence of iridoid and secoiridoid glycosides (IGs), an important group of plant defense compounds, in three species of honeysuckle, Lonicera morrowii A. Gray, Lonicera tatarica L., and their hybrid Lonicera×bella Zabel. (Caprifoliaceae), all of which are considered invasive in various parts of North America. Hybrid genotypes had a diversity of IGs inherited from both parent species, as well as one component not detected in either parent. All three species were similar in that overall concentrations of IGs were significantly higher in fruits than in leaves, and several compounds that were major components of fruits were never found in leaves. However, specific patterns of quantitative distribution among leaves, unripe fruits, and ripe fruits differed among the three species, with a relatively higher allocation to fruits in the hybrid species than for either parent. These patterns likely have important consequences for plant interactions with antagonistic herbivores and pathogens as well as mutualistic seed dispersers, and thus the potential invasiveness of hybrid and parental species in their introduced range. Methods established here for quantitative analysis of IGs will allow for the exploration of many compelling research questions related to the evolutionary ecology and invasion biology of these and other related species in the genus Lonicera.
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Affiliation(s)
- Susan R Whitehead
- Ecology and Evolutionary Biology and Museum of Natural History, University of Colorado at Boulder, UCB 334, Boulder, CO 80309, USA.
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Populus hybrid hosts drive divergence in the herbivorous mite, Aceria parapopuli: implications for conservation of plant hybrid zones as essential habitat. CONSERV GENET 2012. [DOI: 10.1007/s10592-012-0409-z] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Busby PE, Catherine Aime M, Newcombe G. Foliar pathogens of Populus angustifolia are consistent with a hypothesis of Beringian migration into North America. Fungal Biol 2012; 116:792-801. [DOI: 10.1016/j.funbio.2012.04.012] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2011] [Revised: 04/19/2012] [Accepted: 04/24/2012] [Indexed: 11/15/2022]
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Herbivore host-associated genetic differentiation depends on the scale of plant genetic variation examined. Evol Ecol 2012. [DOI: 10.1007/s10682-012-9582-2] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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Jones RC, Steane DA, Lavery M, Vaillancourt RE, Potts BM. Multiple evolutionary processes drive the patterns of genetic differentiation in a forest tree species complex. Ecol Evol 2012; 3:1-17. [PMID: 23403692 PMCID: PMC3568837 DOI: 10.1002/ece3.421] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2012] [Revised: 09/26/2012] [Accepted: 10/03/2012] [Indexed: 12/02/2022] Open
Abstract
Forest trees frequently form species complexes, complicating taxonomic classification and gene pool management. This is certainly the case in Eucalyptus, and well exemplified by the Eucalyptus globulus complex. This ecologically and economically significant complex comprises four taxa (sspp. bicostata, globulus, maidenii, pseudoglobulus) that are geographically and morphologically distinct, but linked by extensive "intergrade" populations. To resolve their genetic affinities, nine microsatellites were used to genotype 1200 trees from throughout the natural range of the complex in Australia, representing 33 morphological core and intergrade populations. There was significant spatial genetic structure (F(ST) = 0.10), but variation was continuous. High genetic diversity in southern ssp. maidenii indicates that this region is the center of origin. Genetic diversity decreases and population differentiation increases with distance from this area, suggesting that drift is a major evolutionary process. Many of the intergrade populations, along with other populations morphologically classified as ssp. pseudoglobulus or ssp. globulus, belong to a "cryptic genetic entity" that is genetically and geographically intermediate between core ssp. bicostata, ssp. maidenii, and ssp. globulus. Geography, rather than morphology, therefore, is the best predictor of overall genetic affinities within the complex and should be used to classify germplasm into management units for conservation and breeding purposes.
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Affiliation(s)
- Rebecca C Jones
- School of Plant Science, University of Tasmania Private Bag 55, Hobart, Tasmania, 7001, Australia ; CRC for Forestry Private Bag 12, Hobart, Tasmania, 7001, Australia
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Evans LM, Clark JS, Whipple AV, Whitham TG. The relative influences of host plant genotype and yearly abiotic variability in determining herbivore abundance. Oecologia 2011; 168:483-9. [PMID: 21918874 DOI: 10.1007/s00442-011-2108-8] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2010] [Accepted: 06/29/2011] [Indexed: 11/29/2022]
Abstract
Both plant genotype and yearly abiotic variation affect herbivore population sizes, but long-term data have rarely been used to contrast the relative contributions of each. Using a hierarchical Bayesian model, we directly compare effects of these two factors on the population size of a common herbivore, Aceria parapopuli, on Populus angustifolia × fremontii F(1) hybrid trees growing in a common garden across 8 years. Several patterns emerged. First, the Bayesian posterior estimates of tree genotype effects on mite gall number ranged from 0.0043 to 229 on a linear scale. Second, year effect sizes across 8 years of study ranged from 0.133 to 1.895. Third, in comparing the magnitudes of genotypic versus yearly variation, we found that genotypic variation was over 130 times greater than variation among years. Fourth, precipitation in the previous year negatively affected gall abundances, but was minimal compared to tree genotype effects. These findings demonstrate the relative importance of tree genotypic variation in determining herbivore population size. However, given the demonstrated sensitivity of cottonwoods to drought, the loss of individual tree genotypes from an altered climate would have catastrophic impacts on mites that are dependent upon these genotypes for their survival.
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Affiliation(s)
- Luke M Evans
- Department of Biological Sciences, The Environmental Genetics and Genomics Laboratory and Merriam-Powell Center for Environmental Research, Northern Arizona University, PO Box 5640, Flagstaff, AZ 86011, USA.
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Tack AJM, Roslin T. The relative importance of host-plant genetic diversity in structuring the associated herbivore community. Ecology 2011; 92:1594-604. [DOI: 10.1890/10-2006.1] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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Krebs C, Gerber E, Matthies D, Schaffner U. Herbivore resistance of invasive Fallopia species and their hybrids. Oecologia 2011; 167:1041-52. [PMID: 21656300 DOI: 10.1007/s00442-011-2035-8] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2010] [Accepted: 05/18/2011] [Indexed: 10/18/2022]
Abstract
Hybridization has been proposed as a mechanism by which exotic plants can increase their invasiveness. By generating novel recombinants, hybridization may result in phenotypes that are better adapted to the new environment than their parental species. We experimentally assessed the resistance of five exotic Fallopia taxa, F. japonica var. japonica, F. sachalinensis and F. baldschuanica, the two hybrids F. × bohemica and F. × conollyana, and the common European plants Rumex obtusifolius and Taraxacum officinale to four native European herbivores, the slug Arion lusitanicus, the moth Noctua pronuba, the grasshopper Metrioptera roeselii and the beetle Gastrophysa viridula. Leaf area consumed and relative growth rate of the herbivores differed significantly between the Fallopia taxa and the native species, as well as among the Fallopia taxa, and was partly influenced by interspecific variation in leaf morphology and physiology. Fallopia japonica, the most abundant Fallopia taxon in Europe, showed the highest level of resistance against all herbivores tested. The level of resistance of the hybrids compared to that of their parental species varied depending on hybrid taxon and herbivore species. Genotypes of the hybrid F. × bohemica varied significantly in herbivore resistance, but no evidence was found that hybridization has generated novel recombinants that are inherently better defended against resident herbivores than their parental species, thereby increasing the hybrid's invasion success. In general, exotic Fallopia taxa showed higher levels of herbivore resistance than the two native plant species, suggesting that both parental and hybrid Fallopia taxa largely escape from herbivory in Europe.
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40
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Bezemer TM, Fountain MT, Barea JM, Christensen S, Dekker SC, Duyts H, van Hal R, Harvey JA, Hedlund K, Maraun M, Mikola J, Mladenov AG, Robin C, de Ruiter PC, Scheu S, Setälä H, Šmilauer P, van der Putten WH. Divergent composition but similar function of soil food webs of individual plants: plant species and community effects. Ecology 2010; 91:3027-36. [DOI: 10.1890/09-2198.1] [Citation(s) in RCA: 172] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Affiliation(s)
- T. M. Bezemer
- Department of Terrestrial Ecology, Netherlands Institute of Ecology (NIOO-KNAW), P.O. Box 40, 6666 ZG Heteren, The Netherlands
- Laboratory of Nematology, Wageningen University and Research Centre, P.O. Box 8123, 6700 ES Wageningen, The Netherlands
| | - M. T. Fountain
- Science Department, East Malling Research, East Malling, Kent ME19 6BJ United Kingdom
| | - J. M. Barea
- Departamento de Microbiología del Suelo y Sistemas Simbióticos, Estación Experimental del Zaidín, CSIC, Profesor Albareda, 1, 18008 Granada, Spain
| | - S. Christensen
- Copenhagen University, Department of Terrestrial Ecology, Ø. Farimagsgade 2D, DK 1353 Copenhagen, Denmark
| | - S. C. Dekker
- Department of Environmental Sciences, Copernicus Institute, Utrecht University, P.O. Box 80115, 3508 TC Utrecht, The Netherlands
| | - H. Duyts
- Department of Terrestrial Ecology, Netherlands Institute of Ecology (NIOO-KNAW), P.O. Box 40, 6666 ZG Heteren, The Netherlands
| | - R. van Hal
- Department of Environmental Sciences, Copernicus Institute, Utrecht University, P.O. Box 80115, 3508 TC Utrecht, The Netherlands
| | - J. A. Harvey
- Department of Terrestrial Ecology, Netherlands Institute of Ecology (NIOO-KNAW), P.O. Box 40, 6666 ZG Heteren, The Netherlands
| | - K. Hedlund
- Department of Ecology, Lund University, S 223 62 Lund, Sweden
| | - M. Maraun
- Georg August University of Goettingen, J.F. Blumenbach Institute of Zoology and Anthropology, Animal Ecology, Berliner Strasse 28, 37073 Goettingen, Germany
| | - J. Mikola
- Department of Ecological and Environmental Sciences, University of Helsinki, Niemenkatu 73, 15140 Lahti, Finland
| | - A. G. Mladenov
- Biodiversity Department, Central Laboratory of General Ecology, 2, Yurii Gagarin Street, 1113 Sofia, Bulgaria
| | - C. Robin
- Nancy Université, (INPL)-INRA, Agronomie et Environment, Nancy-Colmar, BP 172, F-54505 Vandoeuvre-les-Nancy, France
| | - P. C. de Ruiter
- Department of Environmental Sciences, Copernicus Institute, Utrecht University, P.O. Box 80115, 3508 TC Utrecht, The Netherlands
- Soil Centre, Wageningen University and Research Centre, Droevendaalsesteeg 4, 6708 PB Wageningen, The Netherlands
| | - S. Scheu
- Georg August University of Goettingen, J.F. Blumenbach Institute of Zoology and Anthropology, Animal Ecology, Berliner Strasse 28, 37073 Goettingen, Germany
| | - H. Setälä
- Department of Ecological and Environmental Sciences, University of Helsinki, Niemenkatu 73, 15140 Lahti, Finland
| | - P. Šmilauer
- Faculty of Science, University of South Bohemia, Branišovská 31, CZ-370 05 České Budějovice, Czech Republic
| | - W. H. van der Putten
- Department of Terrestrial Ecology, Netherlands Institute of Ecology (NIOO-KNAW), P.O. Box 40, 6666 ZG Heteren, The Netherlands
- Laboratory of Nematology, Wageningen University and Research Centre, P.O. Box 8123, 6700 ES Wageningen, The Netherlands
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Nakamura M, Asanuma M, Hiura T. Differential effects of host plant hybridization on herbivore community structure and grazing pressure on forest canopies. OIKOS 2010. [DOI: 10.1111/j.1600-0706.2010.18255.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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Hamilton CE, Dowling TE, Faeth SH. Hybridization in endophyte symbionts alters host response to moisture and nutrient treatments. MICROBIAL ECOLOGY 2010; 59:768-775. [PMID: 19921327 DOI: 10.1007/s00248-009-9606-9] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/24/2009] [Accepted: 10/17/2009] [Indexed: 05/28/2023]
Abstract
When a host organism is infected by a symbiont, the resulting symbiotum has a phenotype distinct from uninfected hosts. Genotypic interactions between the partners may increase phenotypic variation of the host at the population level. Neotyphodium is an asexual, vertically transmitted endophytic symbiont of grasses often existing in hybrid form. Hybridization in Neotyphodium rapidly increases the symbiotum's genomic content and is likely to increase the phenotypic variation of the host. This phenotypic variation is predicted to enhance host performance, especially in stressful environments. We tested this hypothesis by comparing the growth, survival, and resource allocation of hybrid and nonhybrid infected host plants exposed to controlled variation in soil moisture and nutrients. Infection by a hybrid endophyte did not fit our predictions of comparatively higher root and total biomass production under low moisture/low nutrient treatments. Regardless of whether the host was infected by a hybrid or nonhybrid endophyte, both produced significantly higher root/total biomass when both nutrient and moisture were high compared to limited nutrient/moisture treatments. However, infection by hybrid Neotyphodium did result in significantly higher total biomass and host survival compared to nonhybrid infected hosts, regardless of treatment. Endophyte hybridization alters host strategies in response to stress by increasing survival in depauperate habitats and thus, potentially increasing the relative long-term host fitness.
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Affiliation(s)
- Cyd E Hamilton
- Arizona State University, School of Life Sciences, Tempe, AZ 85287, USA.
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Astles PA, Moore AJ, Preziosi RF. Genetic variation in response to an indirect ecological effect. Proc Biol Sci 2009; 272:2577-81. [PMID: 16321778 PMCID: PMC1559979 DOI: 10.1098/rspb.2005.3174] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Indirect ecological effects (IEEs) are widespread and often as strong as the phenotypic effects arising from direct interactions in natural communities. Indirect effects can influence competitive interactions, and are thought to be important selective forces. However, the extent that selection arising from IEEs results in long-term evolutionary change depends on genetic variation underlying the phenotypic response-that is, a genotype-by-IEE interaction. We provide the first data on genetic variation in the response of traits to an IEE, and illustrate how such genetic variation might be detected and analysed. We used a model tri-trophic system to investigate the effect of host plants on two populations of predatory ladybirds through a clonal aphid herbivore. A split-family experimental design allowed us to estimate the effects of aphid host plant on ladybird traits (IEE) and the extent of genetic variation in ladybird predators for response to these effects (genotype-by-indirect environmental effect interaction). We found significant genetic variation in the response of ladybird phenotypes to the indirect effect of host plant of their aphid prey, demonstrating the potential for evolutionary responses to selection arising from the prey host.
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Affiliation(s)
- Philip A Astles
- Faculty of Life Sciences, 3.614 Stopford Building, The University of ManchesterOxford Road, Manchester M13 9PT, UK
| | - Allen J Moore
- Centre for Ecology and Conservation, University of Exeter in CornwallTremough, Penryn, TR10 9EZ, UK
| | - Richard F Preziosi
- Faculty of Life Sciences, 3.614 Stopford Building, The University of ManchesterOxford Road, Manchester M13 9PT, UK
- Author for correspondence ()
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Abstract
Biological invasions greatly increase the potential for hybridization among native and non-native species. Hybridization may influence the palatability of novel hybrids to consumers potentially influencing invasion success; however, the palatability of non-native hybrids relative to the parent species is poorly known. In contrast, studies of native-only hybrids find they are nearly always more palatable to consumers than the parent species. Here, I experimentally demonstrate that an invasive hybrid cordgrass (Spartina) is dramatically less palatable to grazing geese than the native parent species. Using field and aviary experiments, I show that grazing geese ignore the hybrid cordgrass and preferentially consume native Spartina. I also experimentally demonstrate that reduced herbivory of the invasive hybrid may contribute to faster spread in a California estuary. These results suggest that biological invasions may increase future opportunities for creating novel hybrids that may pose a greater risk to natural systems than the parent species.
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Affiliation(s)
- E Grosholz
- Department of Environmental Science and Policy, University of California, Davis, CA 95616, USA.
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46
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Lojewski NR, Fischer DG, Bailey JK, Schweitzer JA, Whitham TG, Hart SC. Genetic basis of aboveground productivity in two native Populus species and their hybrids. TREE PHYSIOLOGY 2009; 29:1133-1142. [PMID: 19578030 DOI: 10.1093/treephys/tpp046] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Demonstration of genetic control over riparian tree productivity has major implications for responses of riparian systems to shifting environmental conditions and effects of genetics on ecosystems in general. We used field studies and common gardens, applying both molecular and quantitative techniques, to compare plot-level tree aboveground net primary productivity (ANPP(tree)) and individual tree growth rate constants in relation to plant genetic identity in two naturally occurring Populus tree species and their hybrids. In field comparisons of four cross types (Populus fremontii S. Wats., Populus angustifolia James, F(1) hybrids and backcross hybrids) across 11 natural stands, productivity was greatest for P. fremontii trees, followed by hybrids and lowest in P. angustifolia. A similar pattern was observed in four common gardens across a 290 m elevation and 100 km environmental gradient. Despite a doubling in productivity across the common gardens, the relative differences among the cross types remained constant. Using clonal replicates in a common garden, we found ANPP(tree) to be a heritable plant trait (i.e., broad-sense heritability), such that plant genetic factors explained between 38% and 82% of the variation in ANPP(tree). Furthermore, analysis of the genetic composition among individual tree genotypes using restriction fragment length polymorphism molecular markers showed that genetically similar trees also exhibited similar ANPP(tree). These findings indicate strong genetic contributions to natural variation in ANPP with important ecological implications.
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Affiliation(s)
- Nathan R Lojewski
- School of Forestry, Northern Arizona University, Flagstaff, AZ 86011, USA
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47
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Ammann K. Why farming with high tech methods should integrate elements of organic agriculture. N Biotechnol 2009; 25:378-88. [DOI: 10.1016/j.nbt.2009.06.933] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2009] [Revised: 06/14/2009] [Accepted: 06/17/2009] [Indexed: 10/20/2022]
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48
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Bailey JK, Schweitzer JA, Ubeda F, Koricheva J, LeRoy CJ, Madritch MD, Rehill BJ, Bangert RK, Fischer DG, Allan GJ, Whitham TG. From genes to ecosystems: a synthesis of the effects of plant genetic factors across levels of organization. Philos Trans R Soc Lond B Biol Sci 2009; 364:1607-16. [PMID: 19414474 DOI: 10.1098/rstb.2008.0336] [Citation(s) in RCA: 161] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Using two genetic approaches and seven different plant systems, we present findings from a meta-analysis examining the strength of the effects of plant genetic introgression and genotypic diversity across individual, community and ecosystem levels with the goal of synthesizing the patterns to date. We found that (i) the strength of plant genetic effects can be quite high; however, the overall strength of genetic effects on most response variables declined as the levels of organization increased. (ii) Plant genetic effects varied such that introgression had a greater impact on individual phenotypes than extended effects on arthropods or microbes/fungi. By contrast, the greatest effects of genotypic diversity were on arthropods. (iii) Plant genetic effects were greater on above-ground versus below-ground processes, but there was no difference between terrestrial and aquatic environments. (iv) The strength of the effects of intraspecific genotypic diversity tended to be weaker than interspecific genetic introgression. (v) Although genetic effects generally decline across levels of organization, in some cases they do not, suggesting that specific organisms and/or processes may respond more than others to underlying genetic variation. Because patterns in the overall impacts of introgression and genotypic diversity were generally consistent across diverse study systems and consistent with theoretical expectations, these results provide generality for understanding the extended consequences of plant genetic variation across levels of organization, with evolutionary implications.
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Affiliation(s)
- Joseph K Bailey
- Department of Ecology and Evolution, University of Tennessee, Knoxville, TN 37996, USA.
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Hersch-Green EI, Cronn R. Tangled trios?: Characterizing a hybrid zone in Castilleja (Orobanchaceae). AMERICAN JOURNAL OF BOTANY 2009; 96:1519-1531. [PMID: 21628297 DOI: 10.3732/ajb.0800357] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
Hybridization and polyploidization are exceedingly important processes because both influence the ecological envelope and evolutionary trajectory of land plants. These processes are frequently invoked for Castilleja (Indian paintbrushes) as contributors to morphological and genetic novelty and as complicating factors in species delimitations. Here, we provide a detailed analysis of morphological and genetic evidence for hybridization in a well-characterized hybrid swarm involving three broadly sympatric species (C. miniata, C. rhexiifolia, C. sulphurea) in western Colorado. Field-classified hybrids are present at high frequencies at these sites and show morphological intermediacy to and segregate for chloroplast DNA haplotypes with C. rhexiifolia and C. sulphurea. Contrarily, DNA content and AFLP variation show that field-classified hybrids are not recent hybrids but a distinctive fourth taxon. Actual hybrids (plants showing admixture ≥10% for two genotypic groups) comprised 13% of our sample, with most admixture involving C. rhexiifolia, C. sulphurea, and the unknown taxon. The identity of the field-classified "hybrids" remains unknown; they either represent a stabilized hybrid species or a species with uncharacteristically high diversity for color alleles. This study highlights the importance of examining concordance and discordance between morphology, cytology, and genetic criteria to understand the complex evolutionary history of diverse groups such as Castilleja.
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Affiliation(s)
- Erika I Hersch-Green
- Department of Biology, Northern Arizona University, S. Beaver St. Box 5640 Flagstaff, Arizona 86011 USA
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50
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Poelman EH, Dam NM, Loon JJA, Vet LEM, Dicke M. Chemical diversity inBrassica oleraceaaffects biodiversity of insect herbivores. Ecology 2009; 90:1863-77. [DOI: 10.1890/08-0977.1] [Citation(s) in RCA: 108] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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