title: Diversity of Phytophthora Species from Declining Mediterranean Maquis Vegetation, including Two New Species, Phytophthora crassamura and P. ornamentata sp. nov.
abstract: The Mediterranean basin is recognized as a global biodiversity hotspot accounting for more than 25,000 plant species that represent almost 10% of the world's vascular flora. In particular, the maquis vegetation on Mediterranean islands and archipelagos constitutes an important resource of the Mediterranean plant diversity due to its high rate of endemism. Since 2009, a severe and widespread dieback and mortality of Quercus ilex trees and several other plant species of the Mediterranean maquis has been observed in the National Park of La Maddalena archipelago (northeast Sardinia, Italy). Infected plants showed severe decline symptoms and a significant reduction of natural regeneration. First studies revealed the involvement of the highly invasive wide-host range pathogen Phytophthora cinnamomi and several fungal pathogens. Subsequent detailed research led to a better understanding of these epidemics showing that multiple Phytophthora spp. were involved, some of them unknown to science. In total, nine Phytophthora species were isolated from rhizosphere soil samples collected from around symptomatic trees and shrubs including Asparagus albus, Cistus sp., Juniperus phoenicea, J. oxycedrus, Pistacia lentiscus and Rhamnus alaternus. Based on morphological characters, growth-temperature relations and sequence analysis of the ITS and cox1 gene regions, the isolates were identified as Phytophthora asparagi, P. bilorbang, P. cinnamomi, P. cryptogea, P. gonapodyides, P. melonis, P. syringae and two new Clade 6 taxa which are here described as P. crassamura sp. nov. and P. ornamentata sp. nov. Pathogenicity tests supported their possible involvement in the severe decline that is currently threatening the Mediterranean maquis vegetation in the La Maddalena archipelago.
authors.affiliation: Dipartimento di Agraria, Sezione di Patologia vegetale ed Entomologia (SPaVE), Università degli Studi di Sassari, Viale Italia 39, 07100 Sassari, Italy.
authors.forename: Bruno
authors.initials: B
authors.lastname: Scanu
authors.affiliation: Dipartimento di Agraria, Sezione di Patologia vegetale ed Entomologia (SPaVE), Università degli Studi di Sassari, Viale Italia 39, 07100 Sassari, Italy.
authors.forename: Benedetto T
authors.initials: BT
authors.lastname: Linaldeddu
authors.affiliation: Dipartimento di Agraria, Sezione di Patologia vegetale ed Entomologia (SPaVE), Università degli Studi di Sassari, Viale Italia 39, 07100 Sassari, Italy.
authors.forename: Antonio
authors.initials: A
authors.lastname: Deidda
authors.affiliation: Phytophthora Research and Consultancy, Am Rain 9, D-83131, Nußdorf, Germany.|Center for Mediterranean Bioresources and Food (MeditBio), Laboratory of Molecular Biotechnology and Phytopathology, University of Algarve, Campus de Gambelas, 8005-139 Faro, Portugal.
authors.forename: Thomas
authors.initials: T
authors.lastname: Jung
mesh_terms: D044822:Biodiversity; D014644:Genetic Variation; D007558:Italy; D010838:Phytophthora / Q000235:genetics*; D010935:Plant Diseases / Q000382:microbiology*; D018517:Plant Roots / Q000382:microbiology; D029963:Quercus / Q000382:microbiology*; D058441:Rhizosphere; D012988:Soil Microbiology