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Tara Chand - One of the best experts on this subject based on the ideXlab platform.
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Enumeration and Characterization of Bacterial Colonists of a Submersed Aquatic Plant, Eurasian Watermilfoil (Myriophyllum spicatum L.).
Applied and Environmental Microbiology, 1992Co-Authors: Tara Chand, Robin F. Harris, John H. AndrewsAbstract:A simple procedure for enumerating and grouping the bacterial colonists of Eurasian watermilfoil (Myriophyllum spicatum L.) is described. Colony characteristics of bacteria associated with M. spicatum were better defined and more stable on nutrient-poor, diluted nutrient broth agar than on high-nutrient media. Acinetobacter, Cytophaga, Flavobacterium, Moraxella, Pseudomonas and/or Alcaligenes, and Vibrio/Aeromonas spp., as well as two highly fastidious unidentified bacterial groups (gram-negative rods and gram-negative cocci), were associated with cultured watermilfoil during January, February, May, June, July, and August 1988. In Lake Wingra (Madison, Wis.), Micrococcus spp. and enterobacters were also associated with Eurasian watermilfoil during July, August, and October 1987.
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Gas chromatographic determination of flurprimidol in a submersed aquatic plant (Myriophyllum spicatum), soil, and water
Journal of Plant Growth Regulation, 1991Co-Authors: Tara Chand, Carole A. LembiAbstract:Methods for the extraction and quantification of flurprimidol residues in Eurasian watermilfoil (Myriophyllum spicatum), soil, and water are described. The compound was detected and quantified by gas chromatography (GC) with a thermionic specific detector. Its identity was confirmed by gas chromatography-mass spectrometry (GCMS) with detection at m/e 40–320. Recoveries from samples spiked with flurprimidol at 10–10,000 ng ml−1 or g−1 averaged 86.8% for Eurasian watermilfoil shoots, 85.2% for roots, 79.3% for loam soil, and 93.3% for water. In a small-scale experiment under field conditions, approximately 88% of the applied flurprimidol dissipated in 4 weeks. The majority of recovered flurprimidol was found in the water and upper 5 cm soil layer. The half-life of the compound in water was 6.8–8 days during June/July 1989.
John H. Andrews - One of the best experts on this subject based on the ideXlab platform.
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Enumeration and Characterization of Bacterial Colonists of a Submersed Aquatic Plant, Eurasian Watermilfoil (Myriophyllum spicatum L.).
Applied and Environmental Microbiology, 1992Co-Authors: Tara Chand, Robin F. Harris, John H. AndrewsAbstract:A simple procedure for enumerating and grouping the bacterial colonists of Eurasian watermilfoil (Myriophyllum spicatum L.) is described. Colony characteristics of bacteria associated with M. spicatum were better defined and more stable on nutrient-poor, diluted nutrient broth agar than on high-nutrient media. Acinetobacter, Cytophaga, Flavobacterium, Moraxella, Pseudomonas and/or Alcaligenes, and Vibrio/Aeromonas spp., as well as two highly fastidious unidentified bacterial groups (gram-negative rods and gram-negative cocci), were associated with cultured watermilfoil during January, February, May, June, July, and August 1988. In Lake Wingra (Madison, Wis.), Micrococcus spp. and enterobacters were also associated with Eurasian watermilfoil during July, August, and October 1987.
Charles W. Boylen - One of the best experts on this subject based on the ideXlab platform.
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Environmental factors affecting seed germination in Myriophyllum spicatum L.
Aquatic Botany, 1993Co-Authors: Christopher F. Hartleb, John D. Madsen, Charles W. BoylenAbstract:Myriophyllum spicatum L. is a submersed aquatic macrophyte that has colonized aquatic habitats across North America. Vegetative propagation is prevalent in M. spicatum and is highly visible, because of the extraordinary capacity of this plant to spread by fragmentation. Because of this, sexual propagation has been considered of limited importance and little is known about in situ seed germination of this species. Laboratory studies were conducted on seeds of M. spicatum to determine the light and temperature requirements necessary for maximum seed germination. Seed germination was also examined in situ at depths of 1, 3 and 5 m in two bays at Lake George, New York (USA). Significant germination of seeds was observed in the northern bay of the lake, but not in the southern, probably because of increased sedimentation in the latter. Temperatures higher than 15°C were found to be necessary for successful seed germination in laboratory studies; however, light was determined not to be a limiting factor on its own. Seeds buried under more than 2 cm of sediment were shown to experience significant decreases in germination.
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Photosynthetic characteristics of Myriophyllum spicatum and six submersed aquatic macrophyte species native to Lake George, New York
Freshwater Biology, 1991Co-Authors: John D. Madsen, Christopher F. Hartleb, Charles W. BoylenAbstract:SUMMARY. 1 The macrophyte community of Lake George, New York is diverse, composing of forty-eight submersed species representing a wide range of habitats, depth ranges and life-history strategies. The photosynthetic rates of seven representative submersed aquatic macrophytes were determined in laboratory studies using measurements of short-term changes in oxygen concentration at eight light intensities from 0 to 1000 μmol m−2 s−1 at 20°C. The species examined were: Elodea canadensis, Myriophyllum spicatum, Potamogeton amplifolius, P. gramineus, P. praelongus, P. robbinsii, and Vallisneria americana. 2 Comparisons of maximum net photosynthesis, Michaelis–Menten Vmax and Km for photosynthesis versus irradiance, and dark respiration rates correlated with changes in community composition and species distribution with depth. 3 In particular, Myriophyllum spicatum exhibited a high photosynthetic rate (Vmax) and high light requirement (both in compensation point and higher half-saturation constant (Km) indicative of a high light-adapted species. In contrast, the native species exhibited shade-tolerant characteristics. 4 Simple daily carbon balance models indicate that M. spicatum has a higher positive carbon balance near the surface than the native species, but carbon balance decreased more rapidly with decreased light. All species showed greatly reduced carbon balances under a simulated M. spicatum canopy, indicating that native species might not survive. Myriopyllum spicatum leaves would experience self-shading and eventual sloughing.
Raymond M. Newman - One of the best experts on this subject based on the ideXlab platform.
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Genetic diversity and differentiation in populations of invasive Eurasian (Myriophyllum spicatum) and hybrid (Myriophyllum spicatum × Myriophyllum sibiricum) watermilfoil
Invasive Plant Science and Management, 2020Co-Authors: Ryan A. Thum, Gregory M. Chorak, Raymond M. Newman, Jasmine A. Eltawely, Jo A. Latimore, Erick Elgin, Syndell R. ParksAbstract:AbstractPopulation genetic studies of within- and among-population genetic variability are still lacking for managed submerged aquatic plant species, and such studies could provide important information for managers. For example, the extent of within-population genetic variation may influence the potential for managed populations to locally adapt to environmental conditions and control tactics. Similarly, among-population variation may influence whether specific control tactics work equally effectively in different locations. In the case of invasive Eurasian watermilfoil (Myriophyllum spicatum L.), including interspecific hybrids with native northern watermilfoil (Myriophyllum sibiricum Kom.), managers recognize that there is genetic variation for growth and herbicide response. However, it is unclear how much overall genetic variation there is, and how it is structured within and among populations. Here, we studied patterns of within- and among-lake genetic variation in 41 lakes in Michigan and 62 lakes in Minnesota using microsatellite markers. We found that within-lake genetic diversity was generally low, and among-lake genetic diversity was relatively high. However, some lakes were genetically diverse, and some genotypes were shared across multiple lakes. For genetically diverse lakes, managers should explicitly recognize the potential for genotypes to differ in control response and should account for this in monitoring and efficacy evaluation and using pretreatment herbicide screens to predict efficacy. Similarly, managers should consider differences in genetic composition among lakes as a source of variation in the growth and herbicide response of lakes with similar control tactics. Finally, laboratory or field information on control efficacy from one lake may be applied to other lakes where genotypes are shared among lakes.
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was Myriophyllum spicatum l haloragaceae recently introduced to south africa from eurasia
Aquatic Botany, 2016Co-Authors: Philip Weyl, Ryan A. Thum, Raymond M. Newman, Michael L Moody, Julie A CoetzeeAbstract:Abstract There is debate over the native or exotic status of Myriophyllum spicatum L. (Haloragaceae) in South Africa, which has important implications for developing and implementing management strategies. The aim of this study was to determine if M. spicatum was recently introduced from Eurasia by reconstructing the genetic relationships between South African and Eurasian M. spicatum using both a nuclear ribosomal (ITS1-5.8S-ITS2-26S) and a chloroplast intron (trnQ-rps16) sequence from 40 populations. For both these DNA markers, the South African populations were distinct from Eurasian populations, but always stemmed from a European origin. The data suggest that South African and European M. spicatum share a common ancestor, however the divergence of both markers are characteristic of a long period of isolation rather than a recent introduction from Europe. The genetic data from this study suggest that M. spicatum has not been introduced recently, but is most likely a native component of the South African flora.
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fish predation on eurasian watermilfoil Myriophyllum spicatum herbivores and indirect effects on macrophytes
Canadian Journal of Fisheries and Aquatic Sciences, 2006Co-Authors: Darren M Ward, Raymond M. NewmanAbstract:We assessed the effect of fish predation on native and naturalized insect herbivores of the invasive aquatic plant Eurasian watermilfoil (Myriophyllum spicatum) using manipulative field experiments within lakes and a field survey across lakes. For the field experiments, we manipulated sunfish (Lepomis spp.) density in cages in the littoral plant beds of two contrasting lakes: one with many sunfish, few watermilfoil herbivores, and abundant Eurasian watermilfoil; and one with few sunfish, many herbivores, and little Eurasian watermilfoil. Watermilfoil herbivores, including the milfoil weevil (Euhrychiopsis lecontei) and aquatic caterpillars, were suppressed by fish in both experiments. Herbivore density was also negatively related to sunfish abundance in the multiple-lake survey. We conclude that abundant sunfish can strongly suppress watermilfoil herbivores. Furthermore, in one of our experiments there was a marginally significant effect of fish exclosure on watermilfoil, suggesting that fish suppression of watermilfoil herbivores can have a positive, indirect effect on plant growth. Fish predation on macrophyte herbivores may be an important trophic interaction in freshwater lakes. Resume : Nous avons evalue les effets de la predation par les poissons sur les insectes herbivores indigenes et natura- lises vivant sur la plante aquatique envahissante, le myriophylle a epis (Myriophyllum spicatum), par des experiences de manipulation en nature dans les lacs et par un inventaire de terrain dans une serie de lacs. Dans les experiences de terrain, nous avons fait varier la densite des crapets (Lepomis spp.) dans des cages placees dans des herbiers littoraux de deux lacs tres differents, l'un contenant beaucoup de crapets, peu d'herbivores du myriophylle et une forte densite de myriophylle a epis, l'autre avec peu de crapets, de nombreux herbivores et peu de myriophylle a epis. Les herbivores consommateurs de myriophylle, dont le charancon du myriophylle (Euhrychiopsis lecontei) et les chenilles aquatiques, ont ete elimines par les poissons dans les deux experiences. De plus, il existe une relation negative entre la densite des herbivores et l'abondance des crapets dans l'inventaire fait dans la serie de lacs. Nous concluons que, lorsqu'ils sont nombreux, les crapets peuvent reduire fortement les populations d'herbivores consommateurs de myriophylle. De plus, dans l'une de nos experiences, il y avait un effet marginalement significatif de l'exclusion des poissons sur le myrio- phylle, ce qui laisse croire que la suppression des herbivores consommateurs de myriophylle peut avoir un effet positif indirect sur la croissance des plantes. La predation par les poissons des herbivores consommateurs de macrophytes peut donc etre une interaction trophique d'importance dans les lacs d'eau douce. (Traduit par la Redaction) Ward and Newman 1057
Darren M Ward - One of the best experts on this subject based on the ideXlab platform.
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fish predation on eurasian watermilfoil Myriophyllum spicatum herbivores and indirect effects on macrophytes
Canadian Journal of Fisheries and Aquatic Sciences, 2006Co-Authors: Darren M Ward, Raymond M. NewmanAbstract:We assessed the effect of fish predation on native and naturalized insect herbivores of the invasive aquatic plant Eurasian watermilfoil (Myriophyllum spicatum) using manipulative field experiments within lakes and a field survey across lakes. For the field experiments, we manipulated sunfish (Lepomis spp.) density in cages in the littoral plant beds of two contrasting lakes: one with many sunfish, few watermilfoil herbivores, and abundant Eurasian watermilfoil; and one with few sunfish, many herbivores, and little Eurasian watermilfoil. Watermilfoil herbivores, including the milfoil weevil (Euhrychiopsis lecontei) and aquatic caterpillars, were suppressed by fish in both experiments. Herbivore density was also negatively related to sunfish abundance in the multiple-lake survey. We conclude that abundant sunfish can strongly suppress watermilfoil herbivores. Furthermore, in one of our experiments there was a marginally significant effect of fish exclosure on watermilfoil, suggesting that fish suppression of watermilfoil herbivores can have a positive, indirect effect on plant growth. Fish predation on macrophyte herbivores may be an important trophic interaction in freshwater lakes. Resume : Nous avons evalue les effets de la predation par les poissons sur les insectes herbivores indigenes et natura- lises vivant sur la plante aquatique envahissante, le myriophylle a epis (Myriophyllum spicatum), par des experiences de manipulation en nature dans les lacs et par un inventaire de terrain dans une serie de lacs. Dans les experiences de terrain, nous avons fait varier la densite des crapets (Lepomis spp.) dans des cages placees dans des herbiers littoraux de deux lacs tres differents, l'un contenant beaucoup de crapets, peu d'herbivores du myriophylle et une forte densite de myriophylle a epis, l'autre avec peu de crapets, de nombreux herbivores et peu de myriophylle a epis. Les herbivores consommateurs de myriophylle, dont le charancon du myriophylle (Euhrychiopsis lecontei) et les chenilles aquatiques, ont ete elimines par les poissons dans les deux experiences. De plus, il existe une relation negative entre la densite des herbivores et l'abondance des crapets dans l'inventaire fait dans la serie de lacs. Nous concluons que, lorsqu'ils sont nombreux, les crapets peuvent reduire fortement les populations d'herbivores consommateurs de myriophylle. De plus, dans l'une de nos experiences, il y avait un effet marginalement significatif de l'exclusion des poissons sur le myrio- phylle, ce qui laisse croire que la suppression des herbivores consommateurs de myriophylle peut avoir un effet positif indirect sur la croissance des plantes. La predation par les poissons des herbivores consommateurs de macrophytes peut donc etre une interaction trophique d'importance dans les lacs d'eau douce. (Traduit par la Redaction) Ward and Newman 1057
