The morphology, behaviour and molecular phylogeny of Phytophthora taxon Salixsoil and its redesignation as Phytophthora lacustris sp. nov. (31st May 2012)

• Record Type: Journal Article
• Authors: Nechwatal, J.; Bakonyi, J.; Cacciola, S. O.; Cooke, D. E. L.; Jung, T.; Nagy, Z. Á.; Vannini, A.; Vettraino, A. M.; Brasier, C. M.
• Is Part Of: Plant pathology. Volume 62:Number 2(2013:Apr.)
• Page Start: 355
• Page End: 369
• Publication Date: 2012-05-31
• Subjects: Agricultural pests -- Periodicals; Plant diseases -- Periodicals; 632
• DOI: 10.1111/j.1365-3059.2012.02638.x
• Languages: English
• ISSNs: 0032-0862

Abstract

<abstract abstract-type="main" xml:lang="en"> <title> <x xml:space="preserve">Abstract</x> </title> <p>Since its first isolation from <italic>Salix</italic> roots in 1972, isolates of a sexually sterile <italic>Phytophthora</italic> species have been obtained frequently from wet or riparian habitats worldwide and have also been isolated from roots of <italic>Alnus</italic> and <italic>Prunus</italic> spp. Although originally assigned to <italic>Phytophthora gonapodyides</italic> on morphological grounds, it was recognized that these isolates, informally named <italic>P</italic>. taxon Salixsoil, might represent a separate lineage within ITS Clade 6. Based on phylogenetic analyses and comparisons of morphology, growth‐temperature relationships and pathogenicity, this taxon is formally described here as <italic>Phytophthora lacustris</italic> sp. nov. Isolates of <italic>P. lacustris</italic> form a clearly resolved cluster in both ITS and mitochondrial <italic>cox1</italic> phylogenies, basal to most other Clade 6 taxa. <italic>Phytophthora lacustris</italic> shares several unusual behavioural properties with other aquatic Clade 6 species, such as sexual sterility and tolerance of high temperatures, that have been suggested as adaptations to riparian conditions. It appears to be widespread in Europe and has also been detected in Australia, New Zealand and the USA. It was shown to be weakly or moderately aggressive on inoculation to <italic>Alnus</italic>, <italic>Prunus</italic> and <italic>Salix</italic>. The extent of <italic>P. lacustris</italic>' activity as a saprotroph in plant debris in water and as an opportunistic pathogen in riparian habitats needs further investigation. Its pathogenic potential to cultivated fruit trees also deserves attention because <italic>P. lacustris</italic> has apparently been introduced into the nursery trade.</p> </abstract>