Phytophthora gallica sp. nov., a new species from rhizosphere soil of declining oak and reed stands in France and Germany
Jung. T Nechwatal. J
Mycological Research ; 2008 [Vol.112] Pages:1195-1205
Abstract
A non-papillate, slow-growing Phytophthora species, which could not be assigned to any existing taxon, was isolated from rhizosphere soil of a declining oak in Northeast France, and from the rhizosphere of Phragmites australis at Lake Constance in south-west Germany in 1998 and 2004, respectively. We describe this species, previously informally designated Phytophthora taxon ‘G’, as Phytophthora gallica sp. nov. Morphology, growth rates, and pathogenicity against cuttings of riparian tree species and leaves of reed are described and compared with those of morphologically and phylogenetically similar Phytophthora species. P. gallica produces colonieswith limited aerialmyceliumand variable growth patterns. Gametangia are not formed in single ormixed cultures with tester strains of knownmating types. P. gallica produces globose and elongated irregular chlamydospores, of which a high proportion is abortive. Inwater culture irregular hyphal swellings and non-papillate persistent sporangia are formed abundantly. P. gallica ismoderately aggressive to Alnus glutinosa and Fagus sylvatica,weakly aggressive to Quercus robur and Salix alba and non-pathogenic to Fraxinus excelsior and Phragmites australis. According to ITS and mtDNA sequence data P. gallica belongs to a distinct Phytophthora clade,with P. boehmeriae and P. kernoviae being the closest relatives. The origin of P. gallica and its ecological role in wet ecosystems remain unclear.
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