Browsing by Author "Jung, T."
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- Eight new Halophytophthora species from marine and brackish-water ecosystems in Portugal and an updated phylogeny for the genusPublication . Maia, Cristiana; Jung, M. Horta; Carella, G.; Milenković, I.; Janoušek, J.; Tomšovský, M.; Mosca, S.; Schena, L.; Cravador, Alfredo; Moricca, S.; Jung, T.During an oomycete survey in December 2015, 10 previously unknown Halophytophthora taxa were isolated from marine and brackish water of tidal ponds and channels in saltmarshes, lagoon ecosystems and river estuaries at seven sites along the Algarve coast in the South of Portugal. Phylogenetic analyses of LSU and ITS datasets, comprising all described Halophytophthora species, the 10 new Halophytophthora taxa and all relevant and distinctive sequences available from GenBank, provided an updated phylogeny of the genus Halophytophthora s.str. showing for the first time a structure of 10 clades designated as Clades 1-10. Nine of the 10 new Halophytophthora taxa resided in Clade 6 together with H. polymorphica and H. vesicula. Based on differences in morphology and temperature-growth relations and a multigene (LSU, ITS, Btub, hsp90, rpl10, tigA, cox1, nadh1, rps10) phylo-geny, eight new Halophytophthora taxa from Portugal are described here as H. brevisporangia, H. cele-ris, H. frigida, H. lateralis, H. lusitanica, H. macrosporangia, H. sinuata and H. thermoambigua. Three species, H. frigida, H. macrosporangia and H. sinuata, have a homothallic breeding system while the remaining five species are sterile. Pathogenicity and litter decomposition tests are underway to clarify their pathological and ecological role in the marine and brackish-water ecosystems. More oomycete surveys in yet undersurveyed regions of the world and population genetic or phylogenomic analyses of global populations are needed to clarify the origin of the new Halophytophthora species.
- Extensive morphological and behavioural diversity among fourteen new and seven described species in Phytophthora Clade 10 and its evolutionary implicationsPublication . Jung, T.; Milenković, I.; Corcobado, T.; Májek, T.; Janoušek, J.; Kudláček, T.; Tomšovský, M.; Nagy, Z.Á.; Durán, A.; Tarigan, M.; Sanfuentes von Stowasser, E.; Singh, R.; Ferreira, M.; Webber, J. F.; Scanu, B.; Chi, N. M.; Thu, P. Q.; Junaid, M.; Rosmana, A.; Baharuddin, B.; Kuswinanti, T.; Nasri, N.; Kageyama, K.; Hieno, A.; Masuya, H.; Uematsu, S.; Oliva, J.; Redondo, M.; Maia, Cristiana; Matsiakh, I.; Kramarets, V.; O'Hanlon, R.; Tomić, Ž.; Brasier, C. M.; Horta Jung, M.During extensive surveys of global Phytophthora diversity 14 new species detected in natural ecosystems in Chile, Indonesia, USA (Louisiana), Sweden, Ukraine and Vietnam were assigned to Phytophthora major Clade 10 based on a multigene phylogeny of nine nuclear and three mitochondrial gene regions. Clade 10 now comprises three subclades. Subclades 10a and 10b contain species with nonpapillate sporangia, a range of breeding systems and a mainly soil-and waterborne lifestyle. These include the previously described P. afrocarpa, P. gallica and P. intercalaris and eight of the new species: P. ludoviciana, P. procera, P. pseudogallica, P. scandinavica, P. subarctica, P. tenuimura, P. tonkinensis and P. ukrainensis. In contrast, all species in Subclade 10c have papillate sporangia and are self-fertile (or homothallic) with an aerial lifestyle including the known P. boehmeriae, P. gondwanensis, P. kernoviae and P. morindae and the new species P. celebensis, P. chilensis, P. javanensis, P. multiglobulosa, P. pseudochilensis and P. pseudokernoviae. All new Phytophthora species differed from each other and from related species by their unique combinations of morphological characters, breeding systems, cardinal temperatures and growth rates. The biogeography and evolutionary history of Clade 10 are discussed. We propose that the three subclades originated via the early divergence of pre-Gondwanan ancestors > 175 Mya into water-and soilborne and aerially dispersed lineages and subsequently underwent multiple allopatric and sympatric radiations during their global spread.
- Phytophthora acerina sp nov., a new species causing bleeding cankers and dieback of Acer pseudoplatanus trees in planted forests in northern ItalyPublication . Ginetti, Beatrice; Moricca, S.; Squires, J. N.; Cooke, D. E. L.; Ragazzi, A.; Jung, T.A severe dieback of Acer pseudoplatanus trees was noticed in planted forest stands in northern Italy in 2010. Affected trees showed collar rot and aerial bleeding cankers along the stems, leading to crown dieback and eventually death. An unknown Phytophthora species was consistently isolated from necrotic bark and xylem tissue and from rhizosphere soil. Based on its unique combination of morphological and physiological characters and phylogenetic analysis, this new taxon is here described as Phytophthora acerina sp. nov. Phylogenetic analysis of ITS, cox1 and beta-tubulin gene regions demonstrated that P. acerina is unique and forms a separate cluster within the 'P. citricola complex', closely related to P. plurivora. Phytophthora acerina is homothallic with smooth-walled oogonia, thick-walled, mostly aplerotic oospores with a high abortion rate, paragynous antheridia, and persistent, morphologically variable semipapillate sporangia. Four to 5-week-old cultures produced globose to subglobose, appressoria-like and coralloid hyphal swellings and characteristic stromata-like hyphal aggregations. Optimum and maximum temperatures for growth are 25 degrees C and 32 degrees C, respectively. Genetic uniformity of all 15 studied isolates and the apparent absence of this species in the extensive surveys of nurseries, forests and seminatural ecosystems conducted in the previous two decades across Europe indicate a recent clonal introduction to northern Italy. Under-bark inoculation tests demonstrated high aggressiveness of P. acerina to A. pseudoplatanus indicating that this pathogen might be a serious risk to maple plantations and forests in Europe.
- Worldwide forest surveys reveal forty-three new species in Phytophthora major Clade 2 with fundamental implications for the evolution and biogeography of the genus and global plant biosecurityPublication . Jung, T.; Milenković, I.; Balci, Y.; Janoušek, J.; Kudláček, T.; Nagy, Z. Á.; Baharuddin, B.; Bakonyi, J.; Broders, K. D.; Cacciola, S. O.; Chang, T.-T.; Chi, N. M.; Corcobado, T.; Cravador, Alfredo; Đorđević, B.; Durán, A.; Ferreira, M.; Fu, C.- H.; Garcia, L.; Hieno, A.; Ho, H.- H.; Hong, C.; Junaid, M.; Kageyama, K.; Kuswinanti, T.; Maia, Cristiana; Májek, T.; Masuya, H.; Magnano di San Lio, G.; Mendieta-Araica, B.; Nasri, N.; Oliveira, L. S. S.; Pane, A.; Pérez-Sierra, A.; Rosmana, A.; Sanfuentes von Stowasser, E.; Scanu, B.; Singh, R.; Stanivuković, Z.; Tarigan, M.; Thu, P. Q.; Tomić, Z.; Tomšovský, M.; Uematsu, S.; Webber, J. F.; Zheng, H.- C.; Zheng, F.- C.; Brasier, C. M.; Horta Jung, M.During 25 surveys of global Phytophthora diversity, conducted between 1998 and 2020, 43 new species were detected in natural ecosystems and, occasionally, in nurseries and outplantings in Europe, Southeast and East Asia and the Americas. Based on a multigene phylogeny of nine nuclear and four mitochondrial gene regions they were assigned to five of the six known subclades, 2a-c, e and f, of Phytophthora major Clade 2 and the new subclade 2g. The evolutionary history of the Clade appears to have involved the pre-Gondwanan divergence of three extant subclades, 2c, 2e and 2f, all having disjunct natural distributions on separate continents and comprising species with a soilborne and aquatic lifestyle and, in addition, a few partially aerial species in Clade 2c; and the post-Gondwanan evolution of subclades 2a and 2g in Southeast/East Asia and 2b in South America, respectively, from their common ancestor. Species in Clade 2g are soilborne whereas Clade 2b comprises both soil-inhabiting and aerial species. Clade 2a has evolved further towards an aerial lifestyle comprising only species which are predominantly or partially airborne. Based on high nuclear heterozygosity levels ca. 38 % of the taxa in Clades 2a and 2b could be some form of hybrid, and the hybridity may be favoured by an A1/A2 breeding system and an aerial life style. Circumstantial evidence suggests the now 93 described species and informally designated taxa in Clade 2 result from both allopatric non-adaptive and sympatric adaptive radiations. They represent most morphological and physiological characters, breeding systems, lifestyles and forms of host specialism found across the Phytophthora clades as a whole, demonstrating the strong biological cohesiveness of the genus. The finding of 43 previously unknown species from a single Phytophthora clade highlight a critical lack of information on the scale of the unknown pathogen threats to forests and natural ecosystems, underlining the risk of basing plant biosecurity protocols mainly on lists of named organisms. More surveys in natural ecosystems of yet unsurveyed regions in Africa, Asia, Central and South America are needed to unveil the full diversity of the clade and the factors driving diversity, speciation and adaptation in Phytophthora.