title: Some arguments in favor of a Myriophyllum aquaticum growth inhibition test in a water-sediment system as an additional test in risk assessment of herbicides.
abstract: The present study compares the practicability, reproducibility, power, and sensitivity of a Myriophyllum aquaticum growth inhibition test in a water-sediment system with the recently accepted Myriophyllum spicatum test in an equivalent testing system and the standard Lemna sp. test. Special consideration was given to endpoints based on M. aquaticum control plant growth and variability of relative growth rate and yield: shoot length, fresh weight, dry weight, and root weight. Sensitivity analysis was based on tests performed with 3,5-dichlorophenol, atrazine, isoproturon, trifluralin, 2,4-dichlorophenoloxyacetic acid, and dicamba. Growth rates for average M. aquaticum control plants were 0.119 d(-1) and 0.112 d(-1), with average estimated doubling time 6.33 d and 6.74 d for relative growth rate fresh weight and shoot length, respectively. Intrinsic variability of M. aquaticum endpoints was low: 12.9%, 12.5%, and 17.8% for relative growth rate shoot length, relative growth rate fresh weight and yield fresh weight, respectively. The power of the test was fairly high. When the most sensitive endpoints were used for comparison, the 2 Myriophyllum species were similarly sensitive, more sensitive (in the case of auxin simulators), or at least equally sensitive as Lemna minor to other tested herbicides. The M. aquaticum 10-d test with a 7-d exposure period in a water-sediment system has acceptable sensitivity and can provide repeatable, reliable, and reproducible results; therefore, it should not be disregarded as a good and representative additional test in environmental risk assessment.
authors.affiliation: Department of Biology and Ecology, Faculty of Sciences, University of Novi Sad, Novi Sad, Serbia.
authors.forename: Tanja
authors.initials: T
authors.lastname: Tunić
authors.affiliation: Department of Biology and Ecology, Faculty of Sciences, University of Novi Sad, Novi Sad, Serbia.
authors.forename: Varja
authors.initials: V
authors.lastname: Knežević
authors.affiliation: Department of Chemistry, Biochemistry, and Environmental Protection, Faculty of Sciences, University of Novi Sad, Novi Sad, Serbia.
authors.forename: Đurđa
authors.initials: Đ
authors.lastname: Kerkez
authors.affiliation: Department of Chemistry, Biochemistry, and Environmental Protection, Faculty of Sciences, University of Novi Sad, Novi Sad, Serbia.
authors.forename: Aleksandra
authors.initials: A
authors.lastname: Tubić
authors.affiliation: Faculty of Agriculture, University of Novi Sad, Novi Sad, Serbia.
authors.forename: Dragana
authors.initials: D
authors.lastname: Šunjka
authors.affiliation: Faculty of Agriculture, University of Novi Sad, Novi Sad, Serbia.
authors.forename: Sanja
authors.initials: S
authors.lastname: Lazić
authors.affiliation: Institute for Pesticides and Environmental Protection, Belgrade-Zemun, Serbia.
authors.forename: Dragica
authors.initials: D
authors.lastname: Brkić
authors.affiliation: Department of Biology and Ecology, Faculty of Sciences, University of Novi Sad, Novi Sad, Serbia.
authors.forename: Ivana
authors.initials: I
authors.lastname: Teodorović
mesh_terms: D029064:Araceae / Q000187:drug effects / Q000254:growth & development; D019015:Geologic Sediments / Q000737:chemistry*; D006540:Herbicides / Q000737:chemistry / Q000633:toxicity*; D019684:Magnoliopsida / Q000187:drug effects* / Q000254:growth & development; D018517:Plant Roots / Q000187:drug effects / Q000254:growth & development; D018547:Plant Stems / Q000187:drug effects / Q000254:growth & development; D018570:Risk Assessment; D014867:Water / Q000737:chemistry*; D014874:Water Pollutants, Chemical / Q000737:chemistry / Q000633:toxicity*
chemical_list: D006540:Herbicides; D014874:Water Pollutants, Chemical; D014867:Water
keywords: Myriophyllum; Risk assessment; Rooted aquatic macrophytes