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Don Cipollini - One of the best experts on this subject based on the ideXlab platform.
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Appendix A. HPLC chromatographs from Alliaria petiolata leaves and roots.
2016Co-Authors: Ragan M. Callaway, Daniel Prati, Don Cipollini, Kathryn Barto, Giles C. Thelen, Steven G. Hallett, Kristina Stinson, John KlironomosAbstract:HPLC chromatographs from Alliaria petiolata leaves and roots
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Appendix C. Effect of root exudate fractions from Alliaria petiolata on the viability of AM fungi in soils from six sites in Europe and six sites in North America.
2016Co-Authors: Ragan M. Callaway, Daniel Prati, Don Cipollini, Kathryn Barto, Giles C. Thelen, Steven G. Hallett, Kristina Stinson, John KlironomosAbstract:Effect of root exudate fractions from Alliaria petiolata on the viability of AM fungi in soils from six sites in Europe and six sites in North America
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Evidence for Use of Alliaria petiolata in North America by the European Cabbage White Butterfly, Pieris rapae
Psyche: A Journal of Entomology, 2016Co-Authors: Sam L. Davis, Don CipolliniAbstract:Pieris rapae L., an invasive crop pest, may have recently begun using Alliaria petiolata Bieb. (Cavara & Grande), a European invasive biennial. We investigated how P. rapae uses forest habitats for nectar and oviposition and examined larval performance on A. petiolata in the field and laboratory. Being known primarily to occupy open habitats, we found that P. rapae regularly uses forest edge habitats, most surveyed A. petiolata plants had P. rapae damage, and P. rapae successfully used both stages of A. petiolata for larval development.
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Glucosinolate-Related Glucosides in Alliaria petiolata: Sources of Variation in the Plant and Different Metabolism in an Adapted Specialist Herbivore, Pieris rapae
Journal of Chemical Ecology, 2014Co-Authors: Tina Frisch, Don Cipollini, Niels Agerbirk, Samantha Davis, Birger Lindberg MollerAbstract:Specialized metabolites in plants influence their interactions with other species, including herbivorous insects, which may adapt to tolerate defensive phytochemicals. The chemical arsenal of Alliaria petiolata (garlic mustard, Brassicaceae) includes the glucosinolate sinigrin and alliarinoside, a hydroxynitrile glucoside with defensive properties to glucosinolate-adapted specialists. To further our understanding of the chemical ecology of A. petiolata , which is spreading invasively in North America, we investigated the metabolite profile and here report a novel natural product, petiolatamide, which is structurally related to sinigrin. In an extensive study of North American populations of A. petiolata , we demonstrate that genetic population differences as well as developmental regulation contribute to variation in the leaf content of petiolatamide, alliarinoside, sinigrin, and a related glycoside. We furthermore demonstrate widely different metabolic fates of these metabolites after ingestion in the glucosinolate-adapted herbivore Pieris rapae , ranging from simple passage over metabolic conversion to sequestration. The differences in metabolic fate were influenced by plant β-glucosidases, insect-mediated degradation, and the specificity of the larval gut transport system mediating sequestration.
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Do mothers always know best? Oviposition mistakes and resulting larval failure of Pieris virginiensis on Alliaria petiolata, a novel, toxic host
Biological Invasions, 2014Co-Authors: Samantha L. Davis, Don CipolliniAbstract:Alliaria petiolata is a European biennial herb that invades North American forests and has direct negative effects on associated flora and fauna. In some places, A. petiolata has invaded the habitat of Pieris virginiensis, a rare, univoltine butterfly that normally uses native spring ephemeral crucifer hosts. There are occasional observations of P. virginiensis laying eggs on A. petiolata, but the frequency and effects of these “mistake oviposition events” are not yet known. We investigated P. virginiensis oviposition preference through field observations in three locations (NY, OH, PA), and also through laboratory experiments measuring egg deposition of adult females on either a native or invasive crucifer. In addition, we examined neonate larval performance through no-choice feeding assays on both A. petiolata leaves and cabbage leaves painted with A. petiolata leaf extracts. We found that P. virginiensis lays significantly more eggs on the exotic A. petiolata than on its native host Cardamine diphylla in both field and laboratory experiments. Caterpillars fed either A. petiolata leaf tissue or its ethanol extract did not survive to pupation, and most died after only a few days. Continual invasion and persistence of A. petiolata in P. virginiensis habitats may lead to genetic bottlenecking and possibly local extinctions without human intervention.
Cipollini Don - One of the best experts on this subject based on the ideXlab platform.
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Gas Exchange, Growth, and Defense Responses of Invasive Alliaria petiolata (Brassicaceae) and Native Geum vernum (Rosaceae) to Elevated Atmospheric CO2 and Warm Spring Temperatures
SelectedWorks, 2020Co-Authors: Anderson, Laurel J., Cipollini DonAbstract:Premise of Study: Global increases in atmospheric CO2 and temperature may interact in complex ways to influence plant physiology and growth, particularly for species that grow in cool, early spring conditions in temperate forests. Plant species may also vary in their responses to environmental changes; fast‐growing invasives may be more responsive to rising CO2 than natives and may increase production of allelopathic compounds under these conditions, altering species’ competitive interactions. Methods: We examined growth and physiological responses of Alliaria petiolata, an allelopathic, invasive herb, and Geum vernum, a co‐occurring native herb, to ambient and elevated spring temperatures and atmospheric CO2 conditions in a factorial growth chamber experiment. Key Results: At 5 wk, leaves were larger at high temperature, and shoot biomass increased under elevated CO2 only at high temperature in both species. As temperatures gradually warmed to simulate seasonal progression, G. vernum became responsive to CO2 at both temperatures, whereas A. petiolata continued to respond to elevated CO2 only at high temperature. Elevated CO2 increased thickness and decreased nitrogen concentrations in leaves of both species. Alliaria petiolata showed photosynthetic downregulation at elevated CO2, whereas G. vernum photosynthesis increased at elevated temperature. Flavonoid and cyanide concentrations decreased significantly in A. petiolata leaves in the elevated CO2 and temperature treatment. Total glucosinolate concentrations and trypsin inhibitor activities did not vary among treatments. Conclusions: Future elevated spring temperatures and CO2 will interact to stimulate growth for A. petiolata and G. vernum, but there may be reduced allelochemical effects in A. petiolata
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Separating Above- and Belowground Effects of Alliaria petiolata and Lonicera Maackii on The Performance of Impatiens Capensis
SelectedWorks, 2017Co-Authors: Cipollini Kendra, Mcclain, Georgette Y., Cipollini DonAbstract:Invasive plants can exert their effects on native plants through both above- and belowground mechanisms. In a fully factorial field study, we examined the effects of activated carbon addition and removal of aboveground biomass (i.e., cutting) on the survival, growth and reproduction of transplanted Impatiens capensis seedlings in habitats dominated by either Lonicera maackii(honeysuckle) or Alliaria petiolata (garlic mustard). Activated carbon can adsorb organic molecules, including potential allelochemicals. Cutting of A. petiolata increased survival and fruit production of I. capensis, while cutting of L. maackii increased survival and tended to increase fruit production. Carbon application tended to increase survival of I. capensis in A. petiolata-dominated plots, but had no effect in L. maackii-dominated plots. The effects of carbon application on growth and fruit production of I. capensis depended upon the cutting treatment in A. petiolata – dominated plots. In plots where A. petiolata was not cut, carbon application increased height and fruit production. In plots where A. petiolata was cut, carbon application decreased height and tended to decrease fruit production. Impatiens capensis tended to survive longer when in competition with A. petiolata than with L. maackii. While carbon application may benefit native plant growth in the presence of A. petiolata, the addition of activated carbon after removal of aboveground biomass, a source of both allelochemicals and light competition, may have little benefit as an understory plant restoration tool
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Does the Native West Virginia White Butterfly (Pieris Vir- Giniensis) Oviposit on Invasive, Toxic Garlic Mustard (Alliaria petiolata)?
SelectedWorks, 2017Co-Authors: Davis Samantha, Cipollini DonAbstract:Background/Question/Methods Pieris virginiensis Edwards, the West Virginia White butterfly, is a rare, univoltine butterfly that resides in mature riparian forests in the eastern United States. This butterfly uses Brassicaceae family members Cardamine diphylla, C. concatenata, and Arabis laevigata as its primary host plants, and nectars on a wide variety of spring ephemerals. Evidence indicates that P. virginiensis occasionally oviposit on the exotic invasive plant Alliaria petiolata, garlic mustard, but caterpillars do not survive. However, the frequency of oviposition “mistakes” in natural habitats has not been quantified. We systematically surveyed host plants at a site in Morrow Co., OH, that was surveyed in 1988 for P. virginiensis oviposition, to determine when and on which larval host plants oviposition occurs. We examined host plants for eggs and caterpillars, and quantified the presence of predators and damage present. In addition, we examined oviposition preference through oviposition choice tests in Allegany State Park, Salamanca, NY. Butterflies were offered three host plants: first or second year Alliaria petiolata, first or second year Arabis laevigata, or flowering Cardamine diphylla to determine which age and species of plant is most preferred by ovipositing butterflies. Results/Conclusions In Morrow Co., OH; we found two adult butterflies during the first field visit in 2011, and no flying adults during any field visit in 2012. We found no eggs or caterpillars in 2011 and just one egg in 2012; in contrast, the 1988 systematic search of the same area revealed 123 eggs. The lack of flying adults and eggs suggests that this population is severely reduced and possibly extirpated from this site, however, climate change over the last twenty years may have contributed greatly to this site’s declining butterfly population: flight season wind speed, minimum temperature, and maximum temperature all have increased significantly at this site over the last 20 years. During preliminary oviposition trials with two butterflies, the butterflies oviposited all eggs on Alliaria petiolata , even when offered native host plants Cardamine diphylla and Arabis laevigata. Given our preliminary results as well as anecdotal and historical observations, we expect that 2013 field data will confirm and extend the observation that P. virginiensis prefers to lay its eggs on the invasive A. petiolata. There might be a link between increasing Alliaria petiolata in a forested site and decreasing P. virginiensispopulations, however, more work needs to be done
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Half-lives and Field Soil Concentrations of Alliaria petiolata Secondary Metabolites
SelectedWorks, 2017Co-Authors: Barto Kathryn, Cipollini DonAbstract:The allelopathic potential of Alliaria petiolata is well established in the lab, but questions remain about the importance of these processes in natural settings, partly because we know so little about the stability of the purported allelopathic compounds. We determined the half-lives of several flavonoid glycosides produced by A. petiolata in sterile and non-sterile soil at two temperatures. We also attempted to quantify the levels of the glucosinolates and flavonoid glycosides produced by A. petiolata, in field soils. The flavonoid glycosides had half-lives in non-sterile soil ranging from 3 to12 h. Even in sterile soil the longest half-life was only 45.5 h. None of the glucosinolates or flavonoid glycosides produced by A. petiolatawere detected in bulk soil extracts. Only one compound, isovitexin-6″-O-β-d-glucopyranoside, was detected during nine months of biomimetic soil extraction. These very low field levels and short half-lives suggest that the allelopathic effects of A. petiolata are likely either due to degradates of the compounds produced by the plant, or to other unknown mechanisms
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Evidence for Use of Alliaria petiolata in North America by the European Cabbage White Butterfly, \u3cem\u3ePieris rapae\u3c/em\u3e
SelectedWorks, 2017Co-Authors: Davis, Sam L., Cipollini DonAbstract:Pieris rapae L., an invasive crop pest, may have recently begun using Alliaria petiolata Bieb. (Cavara & Grande), a European invasive biennial. We investigated how P. rapae uses forest habitats for nectar and oviposition and examined larval performance on A. petiolata in the field and laboratory. Being known primarily to occupy open habitats, we found that P. rapae regularly uses forest edge habitats, most surveyed A. petiolata plants had P. rapae damage, and P. rapae successfully used both stages of A. petiolata for larval development
Stephanie Enright - One of the best experts on this subject based on the ideXlab platform.
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Overlapping defense responses to water limitation and pathogen attack and their consequences for resistance to powdery mildew disease in garlic mustard, Alliaria petiolata
Chemoecology, 2011Co-Authors: Stephanie Enright, Don CipolliniAbstract:Plant responses to abiotic stress can alter their response to biotic stress. We examined changes in the activity of several defense proteins in response to powdery mildew infection of garlic mustard (Alliaria petiolata) in the greenhouse and in the field. Second, we examined the effects of water limitation on the same defense protein responses, as well as on total soluble protein and glucose concentration, plant growth, and powdery mildew disease development. Similar increases in the activity of peroxidase, chitinase, and β-1-3-glucanase were observed in leaves of plants with substantial powdery mildew disease in both greenhouse- and field-grown plants. In the greenhouse, activities of chitinase and peroxidase as well as total soluble protein and glucose concentrations generally increased with the degree of water limitation. In turn, leaf growth and powdery mildew symptom development decreased as the degree of water limitation increased. This study revealed that plant chemical responses to water limitation and powdery mildew disease can overlap to a large extent, which, in addition to changing microenvironmental conditions and other indicators of plant quality, may underlie the ability of water limitation to inhibit powdery mildew disease symptom development in this wild plant pathosystem.
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Infection by Powdery Mildew Erysiphe cruciferarum (Erysiphaceae) Strongly Affects Growth and Fitness of Alliaria petiolata (Brassicaceae)
American journal of botany, 2007Co-Authors: Stephanie Enright, Don CipolliniAbstract:Garlic mustard (Alliaria petiolata) is an invasive biennial that negatively impacts plant and animal communities throughout North America and lacks significant herbivory in its invasive range. Throughout Ohio, many garlic mustard populations support the powdery mildew fungus Erysiphe cruciferarum, although disease incidence varies among populations and environments. Effects of infection on plant growth, as well as both plant and fungal responses to drought and light conditions, were examined on greenhouse-grown, first-year garlic mustard plants. Also, the effects of the fungus on plant growth and fitness were studied in a naturally growing population of second-year plants in the field. Powdery mildew significantly reduced growth of first-year plants in the greenhouse, eventually causing complete mortality. Simulated drought slowed both plant growth and disease development, independent of light conditions. In the field, plants with little incidence of disease after their first year grew taller during their second year, producing significantly more siliques and twice as many seeds as heavily diseased plants did. Seed germination rates did not differ between plants with different levels of disease severity. Consistent reductions in survival, growth, and fitness caused by fungal infection may reduce populations of garlic mustard. These effects may be more evident in moist sites that favor fungal development.
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Expression of Constitutive and Inducible Chemical Defenses in Native and Invasive Populations of Alliaria petiolata
Journal of Chemical Ecology, 2005Co-Authors: Don Cipollini, Kathryn Barto, Carl Hillstrom, Jeanne Mbagwu, Stephanie EnrightAbstract:The Evolution of Increased Competitive Ability (EICA) hypothesis posits that invasive plants in introduced habitats with reduced herbivore pressure will evolve reduced levels of costly resistance traits. In light of this hypothesis, we examined the constitutive and inducible expression of five chemical defense traits in Alliaria petiolata from four invasive North American and seven native European populations. When grown under common conditions, significant variation among populations within continents was found for trypsin inhibitors and peroxidase activity, and glucosinolates and trypsin inhibitors were significantly jasmonate-inducible across populations. Across populations, constitutive levels of glucosinolates and trypsin inhibitors were negatively correlated with their degree of induction, with three North American populations tending to have lower constitutive levels and higher inducibility of glucosinolates than the seven European populations. Alliarinoside and isovitexin 6″- O -β- d -glucopyranoside levels were both higher in North American plants than in European plants, but levels of these compounds were generally increased by jasmonate in European plants and decreased by the same treatment in North American plants. Aside from the tendency for invasive populations to have reduced constitutive glucosinolate levels coupled with increased inducibility, little support for the predictions of EICA was evident in the chemical defenses that we studied.
Roger C. Anderson - One of the best experts on this subject based on the ideXlab platform.
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Response of the invasive Alliaria petiolata to extreme temperatures and drought
'Wiley', 2021Co-Authors: Roger C. Anderson, Rebecca M. Anderson, Jonathan T. Bauer, Christopher Loebach, Alicia Mullarkey, Megan EngelhardtAbstract:Abstract Alliaria petiolata, a strict biennial in North America, can have an annual alternating high abundance of rosettes and flowering plants. We monitored changes in abundance of rosettes and flowering plants in permanent plots (2004–2014). Three times during our study, the alternating yearly cycle was not observed (2007–2008, 2008–2009, and 2013–2014). We concluded stochastic extreme climate events (ECEs), deviating from long‐term climatic data norms (10th or 90th percentile), likely caused negative organism responses. Long‐term data from a local NOAA station located 25 km from our study site included monthly data (1) total precipitation, (2) number of days with >0.13 cm precipitation, and (3) mean and minimum temperatures. September 2007 met the criteria for ECEs for all monthly variables. We first observed A. petiolata on our study site in 1988, and by the early 1990s, it was abundant. To determine whether September 2007 significantly differed from other September (1984–2014), we used six variables related to drought: (1) total precipitation, (2) number of days with precipitation, (3) number of contiguous days without precipitation, (4) mean monthly temperature, (5) mean maximum daily temperature, and (6) the number of days with temperatures >30°C. The first two variables likely increase plant stress as they decrease, whereas stress declines as the remaining variables decrease. We used the six variables to generate a principal component analysis (PCA) biplot. Axes 1 and 2 accounted for 74.3% of the variance. Record‐breaking minimum temperatures (ECEs) for January (2009) and February–March (2014) likely reduced rosette abundance and disrupted reestablishment of alternating high abundance of rosettes and flowering plants. Our data suggest that a single ECE variable, minimum temperature, and multiple ECE variables related to drought likely had negative effects on A. petiolata
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Measuring short distance dispersal of Alliaria petiolata and determining potential long distance dispersal mechanisms
PeerJ Inc., 2018Co-Authors: Christopher A. Loebach, Roger C. AndersonAbstract:Introduction Alliaria petiolata, an herbaceous plant, has invaded woodlands in North America. Its ecology has been thoroughly studied, but an overlooked aspect of its biology is seed dispersal distances and mechanisms. We measured seed dispersal distances in the field and tested if epizoochory is a potential mechanism for long-distance seed dispersal. Methods Dispersal distances were measured by placing seed traps in a sector design around three seed point sources, which consisted of 15 second-year plants transplanted within a 0.25 m radius circle. Traps were placed at intervals ranging from 0.25–3.25 m from the point source. Traps remained in the field until a majority of seeds were dispersed. Eight probability density functions were fitted to seed trap counts via maximum likelihood. Epizoochory was tested as a potential seed dispersal mechanism for A. petiolata through a combination of field and laboratory experiments. To test if small mammals transport A. petiolata seeds in their fur, experimental blocks were placed around dense A. petiolata patches. Each block contained a mammal inclusion treatment (MIT) and control. The MIT consisted of a wood-frame (31 × 61× 31 cm) covered in wire mesh, except for the two 31 × 31 cm ends, placed over a germination tray filled with potting soil. A pan filled with bait was placed in the center of the tray. The control frame (11 × 31 × 61 cm) was placed over a germination tray and completely covered in wire mesh to exclude animal activity. Treatments were in the field for peak seed dispersal. In March, trays were moved to a greenhouse and A. petiolata seedlings were counted and then compared between treatments. To determine if A. petiolata seeds attach to raccoon (Procyon lotor) and white-tailed deer (Odocoileus virginianus) fur, wet and dry seeds were dropped onto wet and dry fur. Furs were rotated 180 degrees and the seeds that remained attached were counted. To measure seed retention, seeds were dropped on furs and rotated as before, then the furs were agitated for one hour. The seeds retained in the fur were counted. Results For the seed dispersal experiment, the 2Dt function provided the best fit and was the most biologically meaningful. It predicted that seed density rapidly declined with distance from the point source. Mean dispersal distance was 0.52 m and 95% of seeds dispersed within 1.14 m. The epizoochory field experiment showed increased mammal activity and A. petiolata seedlings in germination trays of the MIT compared to control. Laboratory studies showed 3–26% of seeds were attached and retained by raccoon and deer fur. Retention significantly increased if either seed or fur were wet (57–98%). Discussion Without animal seed vectors, most seeds fall within a short distance of the seed source; however, long distance dispersal may be accomplished by epizoochory. Our data are consistent with A. petiolata’s widespread distribution and development of dense clusters of the species in invaded areas
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Inbreeding depression and partitioning of genetic load in the invasive biennial Alliaria petiolata (Brassicaceae).
American journal of botany, 2013Co-Authors: Alicia A. Mullarkey, Diane L. Byers, Roger C. AndersonAbstract: Premise of the study: Invasive species are nonnative species that enter novel environments, establish sustained populations, and can negatively impact native species. Here we assess a potential weakness of invasive species (genetic load) and show how species might overcome genetic barriers. Colonization of novel habitats by invasive species typically involves few individuals, exposing populations to founder effects. We empirically tested a central Illinois population of an invasive biennial plant, Alliaria petiolata , for evidence of a founder effect by assessing the pattern of genetic load. Methods: To estimate genetic load, we assayed offspring from three cross types (self-pollinated, outcrossed within- and between-populations) in a greenhouse. Vegetative and reproductive traits were measured on fi rst-year plants grown with or without intraspecifi c competition. Key results: We found substantial genetic load in this population of A. petiolata, which can mostly be attributed to genetic drift (founder effect) and not inbreeding depression. Between-population heterosis was expressed more than inbreeding depression under intraspecifi c competition. Conclusions: Inbreeding may be adaptive for A. petiolata in its introduced range by providing reproductive assurance, with limited inbreeding load. Nevertheless, most of the genetic load in this population of A. petiolata is due to fiof deleterious alleles. Drift load is expected, given that this population is near the edge of its continuous geographic range in highly fragmented habitats, and gene fl ow between isolated populations is likely highly limited. Preventing additional introduction and movement of propagules between isolated local populations should reduce heterosis and A. petiolata competitiveness.
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phenological niche separation from native species increases reproductive success of an invasive species Alliaria petiolata brassicaceae garlic mustard1
Journal of The Torrey Botanical Society, 2011Co-Authors: Megan Jean Engelhardt, Roger C. AndersonAbstract:Abstract Successful biological invasion requires correspondence between invader functional traits and their utility in novel environments. We focused on specific phenological and ecophysiological characteristics of an herbaceous biennial, Alliaria petiolata, related to its successful invasion of deciduous forest groundlayers in eastern North America. We tested for phenological separation between A. petiolata and native groundlayer species during spring of its second year, when the plant accumulates 91% of its total biomass, and assessed importance of availability of high irradiance before tree canopy closure on growth and reproductive output. We experimentally shaded plants in situ during three intervals: Early: before native groundlayer was well developed (3 March–20 April), Mid: 21 April to tree canopy closure (18 May), and Late: after canopy closure to 29 May. We measured maximum photosynthetic rates (Amax) in early (13–14 April) and late (22–26 May) spring. Alliaria petiolata began rapid growth and re...
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competitive interactions among first year and second year plants of the invasive biennial garlic mustard Alliaria petiolata and native ground layer vegetation
Restoration Ecology, 2010Co-Authors: Roger C. Anderson, Jonathan T. Bauer, Rebecca M. AndersonAbstract:We studied the effects of hand weeding of second-year plants of the biennial garlic mustard (Alliaria petiolata) on first-year plants (seedlings) and native ground layer vegetation. Garlic mustard is a Eurasian species that has invaded deciduous forest ground layers in eastern North America. Treatments consisted of a control and an early or late weeding of second-year garlic mustard. The early treatment (early March) was applied before garlic mustard seeds had germinated and when most native species were dormant. The late treatment (mid-May) occurred after plants had bolted, flowering was occurring, and most native species and new garlic mustard seedlings were actively growing. Pre-treatment data were obtained in 2004 and treated and control plots were sampled in 2005, 2006, and 2007. No significant treatment effects were observed in 2004 or 2005. In 2006, mean cover of first-year plants was higher in the early weeding treatment than in the late weeding treatment and control. In 2007, mean cover of first-year garlic mustard was higher in the control than in either of the two weeding treatments. There were no significant treatment effects in any year on native vegetation cover, bare ground, or the five most abundant native species. Our data indicate that (1) late weeding of garlic mustard provided more effective control than early weeding because late weeding allows second-year plants to compete with garlic mustard seedlings for a longer period of time and (2) competition between first- and second-year plants is responsible for alternating dominance of first-year and second-year garlic mustard plants.
Oliver Bossdorf - One of the best experts on this subject based on the ideXlab platform.
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molecular evidence for multiple introductions of garlic mustard Alliaria petiolata brassicaceae to north america
Molecular Ecology, 2005Co-Authors: Walter Durka, Oliver Bossdorf, Daniel Prati, Harald AugeAbstract:Invasive species offer excellent model systems for studying rapid evolutionary change. In this context, molecular markers play an important role because they provide information about pathways of introduction, the amount of genetic variation introduced, and the extent to which founder effects and inbreeding after population bottlenecks may have contributed to evolutionary change. Here, we studied microsatellite variation in eight polymorphic loci among and within 27 native and 26 introduced populations of garlic mustard ( Alliaria petiolata ), a European herb which is a current serious invader in North American deciduous forests. Overall, introduced populations were genetically less diverse. However, considerable variability was present and when compared to the probable source regions, no bottleneck was evident. Observed heterozygosity was very low and resulted in high inbreeding coefficients, which did not differ significantly between native and introduced populations. Thus, selfing seems to be equally dominant in both ranges. Consequently, there was strong population differentiation in the native ( F ST = 0.704) and the introduced ( F ST = 0.789) ranges. The high allelic diversity in the introduced range strongly suggests multiple introductions of Alliaria petiolata to North America. Out of six European regions, the British Isles, northern Europe, and central Europe had significantly higher proportions of alleles, which are common to the introduced range, and are therefore the most probable source regions. The genetic diversity established by multiple introductions, and the lack of inbreeding depression in this highly selfing species, may have contributed to the invasion success of Alliaria petiolata .
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Isolation and characterization of microsatellite loci in the invasive Alliaria petiolata (Brassicaceae)
Molecular Ecology Notes, 2004Co-Authors: Walter Durka, Oliver Bossdorf, B. GautschiAbstract:Isolation and characterization of microsatellite loci in the invasive Alliaria petiolata (Brassicaceae).
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palatability and tolerance to simulated herbivory in native and introduced populations of Alliaria petiolata brassicaceae
American Journal of Botany, 2004Co-Authors: Oliver Bossdorf, Daniel Prati, Stefan Schroder, Harald AugeAbstract:The European herb garlic mustard (Alliaria petiolata) is a serious invader of North American deciduous forests. One explanation for its success could be that in the absence of specialized herbivores, selection has favored less defended but more vigorous genotypes. This idea was addressed by comparing offspring from several native and introduced Alliaria populations with respect to their palatability to insect herbivores and their tolerance to simulated herbivory. Feeding rates of a specialist weevil from the native range were significantly greater on American plants, suggesting a loss of resistance in the introduced range. In contrast, there was significant population variation but no continent effect in the feeding rates of a generalist caterpillar. After simulated herbivory, A. petiolata showed a substantial regrowth capacity that involved changes in plant growth, architecture, and allocation. Removal of 75% leaf area or of all bolting stems reduced plant fitness to 81% and 58%, respectively, of the fitness of controls. There was no indication of a difference in tolerance between native and introduced Alliaria populations or of a trade-off between tolerance and resistance.
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allelopathic inhibition of germination by Alliaria petiolata brassicaceae
American Journal of Botany, 2004Co-Authors: Daniel Prati, Oliver BossdorfAbstract:Garlic mustard (Alliaria petiolata, Brassicaceae) is an invasive, nonindigenous species currently invading the understory of North American woodlands where it is a serious threat to the native flora. Part of this success might be due to allelopathic interference by garlic mustard. Two congeneric species, the European Geum urbanum and the North American Geum laciniatum, were tested for allelopathic inhibition of germination by garlic mustard. Seeds were germinated either on substrate contaminated by garlic mustard or on substrate with contamination neutralized by activated carbon. Allelopathic effects of native European and invasive North American garlic mustard populations were also compared. Activated carbon increased germination by 14%, indicating that garlic mustard contaminated the substrate through root exudates. Activated carbon in turn counteracted this effect. The two test species differed in their sensitivity to allelopathic interference. North American G. laciniatum had a much stronger increase in germination when activated carbon was added to the substrate, independent of the origin of garlic mustard. In contrast, the European G. urbanum germinated better in substrate precultivated with North American garlic mustard, whereas activated carbon increased its germination only in substrate precultivated with European garlic mustard.