title: Marine Phytophthora species can hamper conservation and restoration of vegetated coastal ecosystems.
abstract: Phytophthora species are potent pathogens that can devastate terrestrial plants, causing billions of dollars of damage yearly to agricultural crops and harming fragile ecosystems worldwide. Yet, virtually nothing is known about the distribution and pathogenicity of their marine relatives. This is surprising, as marine plants form vital habitats in coastal zones worldwide (i.e. mangrove forests, salt marshes, seagrass beds), and disease may be an important bottleneck for the conservation and restoration of these rapidly declining ecosystems. We are the first to report on widespread infection of Phytophthora and Halophytophthora species on a common seagrass species, Zostera marina (eelgrass), across the northern Atlantic and Mediterranean. In addition, we tested the effects of Halophytophthora sp. Zostera and Phytophthora gemini on Z. marina seed germination in a full-factorial laboratory experiment under various environmental conditions. Results suggest that Phytophthora species are widespread as we found these oomycetes in eelgrass beds in six countries across the North Atlantic and Mediterranean. Infection by Halophytophthora sp. Zostera, P. gemini, or both, strongly affected sexual reproduction by reducing seed germination sixfold. Our findings have important implications for seagrass ecology, because these putative pathogens probably negatively affect ecosystem functioning, as well as current restoration and conservation efforts.
authors: Department of Aquatic Ecology and Environmental Biology, Institute for Water and Wetland research, Radboud University, Heyendaalseweg 135, 6525 AJ, Nijmegen, The Netherlands Conservation Ecology Group, Groningen Institute for Evolutionary Life Sciences, University of Groningen, Post Office Box 11103, 9700 CC, Groningen, The Netherlands l.l.govers@rug.nl.
authors: Laura L
authors: 0000-0003-4532-9419
authors: LL
authors: Govers
authors: Department of Mycology, National Plant Protection Organisation (NPPO-NL), Post Office Box 9102, 6700 HC, Wageningen, The Netherlands.
authors: Willem A
authors: WA
authors: Man In 't Veld
authors: Department of Mycology, National Plant Protection Organisation (NPPO-NL), Post Office Box 9102, 6700 HC, Wageningen, The Netherlands.
authors: Johan P
authors: JP
authors: Meffert
authors: Conservation Ecology Group, Groningen Institute for Evolutionary Life Sciences, University of Groningen, Post Office Box 11103, 9700 CC, Groningen, The Netherlands Department of Spatial Ecology, Royal Netherlands Institute for Sea Research, Post Office Box 140, 4400 AC, Yerseke, The Netherlands.
authors: Tjeerd J
authors: TJ
authors: Bouma
authors: Department of Mycology, National Plant Protection Organisation (NPPO-NL), Post Office Box 9102, 6700 HC, Wageningen, The Netherlands.
authors: Patricia C J
authors: PC
authors: van Rijswick
authors: The Fieldwork Company, Stockholmstraat 2b, 9723 BC, Groningen, The Netherlands.
authors: Jannes H T
authors: JH
authors: Heusinkveld
authors: Virginia Institute of Marine Science, College of William and Mary, Box 1346 Gloucester Point, VA 23062, USA.
authors: Robert J
authors: RJ
authors: Orth
authors: Department of Environmental Science, Institute for Water and Wetland research, Radboud University, Heyendaalseweg 135, 6525 AJ, Nijmegen, The Netherlands.
authors: Marieke M
authors: MM
authors: van Katwijk
authors: Department of Aquatic Ecology and Environmental Biology, Institute for Water and Wetland research, Radboud University, Heyendaalseweg 135, 6525 AJ, Nijmegen, The Netherlands.
authors: Tjisse
authors: T
authors: van der Heide
mesh_terms: D003247:Conservation of Natural Resources; D017753:Ecosystem; D052918:Environmental Restoration and Remediation; D010838:Phytophthora / Q000472:pathogenicity*; D035962:Zosteraceae / Q000382:microbiology*
keywords: Halophytophthora; Phytophthora gemini; Zostera marina; pathogen; seagrass; sexual reproduction