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 biosecurity.

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. Taxonomic novelties: New species: Phytophthora amamensis T. Jung, K. Kageyama, H. Masuya & S. Uematsu, Phytophthora angustata T. Jung, L. Garcia, B. Mendieta-Araica, & Y. Balci, Phytophthora balkanensis I. Milenkovic, Z. Tomic, T. Jung & M. Horta Jung, Phytophthora borneensis T. Jung, A. Durán, M. Tarigan & M. Horta Jung, Phytophthora calidophila T. Jung, Y. Balci, L. Garcia & B. Mendieta-Araica, Phytophthora catenulata T. Jung, T.-T. Chang, N.M. Chi & M. Horta Jung, Phytophthora celeris T. Jung, L. Oliveira, M. Tarigan & I. Milenkovic, Phytophthora curvata T. Jung, A. Hieno, H. Masuya & M. Horta Jung, Phytophthora distorta T. Jung, A. Durán, E. Sanfuentes von Stowasser & M. Horta Jung, Phytophthora excentrica T. Jung, S. Uematsu, K. Kageyama & C.M. Brasier, Phytophthora falcata T. Jung, K. Kageyama, S. Uematsu & M. Horta Jung, Phytophthora fansipanensis T. Jung, N.M. Chi, T. Corcobado & C.M. Brasier, Phytophthora frigidophila T. Jung, Y. Balci, K. Broders & I. Milenkovic, Phytophthora furcata T. Jung, N.M. Chi, I. Milenkovic & M. Horta Jung, Phytophthora inclinata N.M. Chi, T. Jung, M. Horta Jung & I. Milenkovic, Phytophthora indonesiensis T. Jung, M. Tarigan, L. Oliveira & I. Milenkovic, Phytophthora japonensis T. Jung, A. Hieno, H. Masuya & J.F. Webber, Phytophthora limosa T. Corcobado, T. Majek, M. Ferreira & T. Jung, Phytophthora macroglobulosa H.-C. Zeng, H.-H. Ho, F.-C. Zheng & T. Jung, Phytophthora montana T. Jung, Y. Balci, K. Broders & M. Horta Jung, Phytophthora multipapillata T. Jung, M. Tarigan, I. Milenkovic & M. Horta Jung, Phytophthora multiplex T. Jung, Y. Balci, K. Broders & M. Horta Jung, Phytophthora nimia T. Jung, H. Masuya, A. Hieno & C.M. Brasier, Phytophthora oblonga T. Jung, S. Uematsu, K. Kageyama & C.M. Brasier, Phytophthora obovoidea T. Jung, Y. Balci, L. Garcia & B. Mendieta-Araica, Phytophthora obturata T. Jung, N.M. Chi, I. Milenkovic & M. Horta Jung, Phytophthora penetrans T. Jung, Y. Balci, K. Broders & I. Milenkovic, Phytophthora platani T. Jung, A. Pérez-Sierra, S.O. Cacciola & M. Horta Jung, Phytophthora proliferata T. Jung, N.M. Chi, I. Milenkovic & M. Horta Jung, Phytophthora pseudocapensis T. Jung, T.-T. Chang, I. Milenkovic & M. Horta Jung, Phytophthora pseudocitrophthora T. Jung, S.O. Cacciola, J. Bakonyi & M. Horta Jung, Phytophthora pseudofrigida T. Jung, A. Durán, M. Tarigan & M. Horta Jung, Phytophthora pseudoccultans T. Jung, T.-T. Chang, I. Milenkovic & M. Horta Jung, Phytophthora pyriformis T. Jung, Y. Balci, K.D. Boders & M. Horta Jung, Phytophthora sumatera T. Jung, M. Tarigan, M. Junaid & A. Durán, Phytophthora transposita T. Jung, K. Kageyama, C.M. Brasier & H. Masuya, Phytophthora vacuola T. Jung, H. Masuya, K. Kageyama & J.F. Webber, Phytophthora valdiviana T. Jung, E. Sanfuentes von Stowasser, A. Durán & M. Horta Jung, Phytophthora variepedicellata T. Jung, Y. Balci, K. Broders & I. Milenkovic, Phytophthora vietnamensis T. Jung, N.M. Chi, I. Milenkovic & M. Horta Jung, Phytophthora ×australasiatica T. Jung, N.M. Chi, M. Tarigan & M. Horta Jung, Phytophthora ×lusitanica T. Jung, M. Horta Jung, C. Maia & I. Milenkovic, Phytophthora ×taiwanensis T. Jung, T.-T. Chang, H.-S. Fu & M. Horta Jung. Citation: Jung T, Milenkovic I, Balci Y, Janousek J, Kudlácek T, Nagy ZÁ, Baharuddin B, Bakonyi J, Broders KD, Cacciola SO, Chang T-T, Chi NM, Corcobado T, Cravador A, Dordevic B, Durán A, Ferreira M, Fu C-H, Garcia L, Hieno A, Ho H-H, Hong C, Junaid M, Kageyama K, Kuswinanti T, Maia C, Májek T, Masuya H, Magnano di San Lio G, Mendieta-Araica B, Nasri N, Oliveira LSS, Pane A, Pérez-Sierra A, Rosmana A, Sanfuentes von Stowasser E, Scanu B, Singh R, Stanivukovic Z, Tarigan M, Thu PQ, Tomic Z, Tomsovský M, Uematsu S, Webber JF, Zeng H-C, Zheng F-C, Brasier CM, Horta Jung M (2024). 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 biosecurity. Studies in Mycology 107: 251-388. doi: 10.3114/sim.2024.107.04.

Genera of phytopathogenic fungi: GOPHY 4.

This paper is the fourth contribution in the Genera of Phytopathogenic Fungi (GOPHY) series. The series provides morphological descriptions and information about the pathology, distribution, hosts and disease symptoms, as well as DNA barcodes for the taxa covered. Moreover, 12 whole-genome sequences for the type or new species in the treated genera are provided. The fourth paper in the GOPHY series covers 19 genera of phytopathogenic fungi and their relatives, including Ascochyta, Cadophora, Celoporthe, Cercospora, Coleophoma, Cytospora, Dendrostoma, Didymella, Endothia, Heterophaeomoniella, Leptosphaerulina, Melampsora, Nigrospora, Pezicula, Phaeomoniella, Pseudocercospora, Pteridopassalora, Zymoseptoria, and one genus of oomycetes, Phytophthora. This study includes two new genera, 30 new species, five new combinations, and 43 typifications of older names. Taxonomic novelties: New genera: Heterophaeomoniella L. Mostert, C.F.J. Spies, Halleen & Gramaje, Pteridopassalora C. Nakash. & Crous; New species: Ascochyta flava Qian Chen & L. Cai, Cadophora domestica L. Mostert, R. van der Merwe, Halleen & Gramaje, Cadophora rotunda L. Mostert, R. van der Merwe, Halleen & Gramaje, Cadophora vinacea J.R. Úrbez-Torres, D.T. O'Gorman & Gramaje, Cadophora vivarii L. Mostert, Havenga, Halleen & Gramaje, Celoporthe foliorum H. Suzuki, Marinc. & M.J. Wingf., Cercospora alyssopsidis M. Bakhshi, Zare & Crous, Dendrostoma elaeocarpi C.M. Tian & Q. Yang, Didymella chlamydospora Qian Chen & L. Cai, Didymella gei Qian Chen & L. Cai, Didymella ligulariae Qian Chen & L. Cai, Didymella qilianensis Qian Chen & L. Cai, Didymella uniseptata Qian Chen & L. Cai, Endothia cerciana W. Wang. & S.F. Chen, Leptosphaerulina miscanthi Qian Chen & L. Cai, Nigrospora covidalis M. Raza, Qian Chen & L. Cai, Nigrospora globospora M. Raza, Qian Chen & L. Cai, Nigrospora philosophiae-doctoris M. Raza, Qian Chen & L. Cai, Phytophthora transitoria I. Milenkovic, T. Májek & T. Jung, Phytophthora panamensis T. Jung, Y. Balci, K. Broders & I. Milenkovic, Phytophthora variabilis T. Jung, M. Horta Jung & I. Milenkovic, Pseudocercospora delonicicola C. Nakash., L. Suhaizan & I. Nurul Faziha, Pseudocercospora farfugii C. Nakash., I. Araki, & Ai Ito, Pseudocercospora hardenbergiae Crous & C. Nakash., Pseudocercospora kenyirana C. Nakash., L. Suhaizan & I. Nurul Faziha, Pseudocercospora perrottetiae Crous, C. Nakash. & C.Y. Chen, Pseudocercospora platyceriicola C. Nakash., Y. Hatt, L. Suhaizan & I. Nurul Faziha, Pseudocercospora stemonicola C. Nakash., Y. Hatt., L. Suhaizan & I. Nurul Faziha, Pseudocercospora terengganuensis C. Nakash., Y. Hatt., L. Suhaizan & I. Nurul Faziha, Pseudocercospora xenopunicae Crous & C. Nakash.; New combinations: Heterophaeomoniella pinifoliorum (Hyang B. Lee et al.) L. Mostert, C.F.J. Spies, Halleen & Gramaje, Pseudocercospora pruni-grayanae (Sawada) C. Nakash. & Motohashi., Pseudocercospora togashiana (K. Ito & Tak. Kobay.) C. Nakash. & Tak. Kobay., Pteridopassalora nephrolepidicola (Crous & R.G. Shivas) C. Nakash. & Crous, Pteridopassalora lygodii (Goh & W.H. Hsieh) C. Nakash. & Crous; Typification: Epitypification: Botrytis infestans Mont., Cercospora abeliae Katsuki, Cercospora ceratoniae Pat. & Trab., Cercospora cladrastidis Jacz., Cercospora cryptomeriicola Sawada, Cercospora dalbergiae S.H. Sun, Cercospora ebulicola W. Yamam., Cercospora formosana W. Yamam., Cercospora fukuii W. Yamam., Cercospora glochidionis Sawada, Cercospora ixorana J.M. Yen & Lim, Cercospora liquidambaricola J.M. Yen, Cercospora pancratii Ellis & Everh., Cercospora pini-densiflorae Hori & Nambu, Cercospora profusa Syd. & P. Syd., Cercospora pyracanthae Katsuki, Cercospora horiana Togashi & Katsuki, Cercospora tabernaemontanae Syd. & P. Syd., Cercospora trinidadensis F. Stevens & Solheim, Melampsora laricis-urbanianae Tak. Matsumoto, Melampsora salicis-cupularis Wang, Phaeoisariopsis pruni-grayanae Sawada, Pseudocercospora angiopteridis Goh & W.H. Hsieh, Pseudocercospora basitruncata Crous, Pseudocercospora boehmeriigena U. Braun, Pseudocercospora coprosmae U. Braun & C.F. Hill, Pseudocercospora cratevicola C. Nakash. & U. Braun, Pseudocercospora cymbidiicola U. Braun & C.F. Hill, Pseudocercospora dodonaeae Boesew., Pseudocercospora euphorbiacearum U. Braun, Pseudocercospora lygodii Goh & W.H. Hsieh, Pseudocercospora metrosideri U. Braun, Pseudocercospora paraexosporioides C. Nakash. & U. Braun, Pseudocercospora symploci Katsuki & Tak. Kobay. ex U. Braun & Crous, Septogloeum punctatum Wakef.; Neotypification: Cercospora aleuritis I. Miyake; Lectotypification: Cercospora dalbergiae S.H. Sun, Cercospora formosana W. Yamam., Cercospora fukuii W. Yamam., Cercospora glochidionis Sawada, Cercospora profusa Syd. & P. Syd., Melampsora laricis-urbanianae Tak. Matsumoto, Phaeoisariopsis pruni-grayanae Sawada, Pseudocercospora symploci Katsuki & Tak. Kobay. ex U. Braun & Crous. Citation: Chen Q, Bakhshi M, Balci Y, Broders KD, Cheewangkoon R, Chen SF, Fan XL, Gramaje D, Halleen F, Horta Jung M, Jiang N, Jung T, Májek T, Marincowitz S, Milenkovic T, Mostert L, Nakashima C, Nurul Faziha I, Pan M, Raza M, Scanu B, Spies CFJ, Suhaizan L, Suzuki H, Tian CM, Tomsovský M, Úrbez-Torres JR, Wang W, Wingfield BD, Wingfield MJ, Yang Q, Yang X, Zare R, Zhao P, Groenewald JZ, Cai L, Crous PW (2022). Genera of phytopathogenic fungi: GOPHY 4. Studies in Mycology 101: 417-564. doi: 10.3114/sim.2022.101.06.

Extensive morphological and behavioural diversity among fourteen new and seven described species in Phytophthora Clade 10 and its evolutionary implications.

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. Citation: Jung T, Milenkovic I, Corcobado T, et al. 2022. Extensive morphological and behavioural diversity among fourteen new and seven described species in Phytophthora Clade 10 and its evolutionary implications. Persoonia 49: 1-57. https://doi.org/10.3767/persoonia.2022.49.01.

Eight new Halophytophthora species from marine and brackish-water ecosystems in Portugal and an updated phylogeny for the genus.

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. Citation: Maia C, Horta Jung M, Carella G, et al. 2022. Eight new Halophytophthora species from marine and brackish-water ecosystems in Portugal and an updated phylogeny for the genus. Persoonia 48: 54 - 90. https://doi.org/10.3767/persoonia.2022.48.02..

A re-evaluation of Neotropical Junghuhnia s.lat. (Polyporales, Basidiomycota) based on morphological and multigene analyses.

Junghuhnia is a genus of polypores traditionally characterised by a dimitic hyphal system with clamped generative hyphae and presence of encrusted skeletocystidia. However, recent molecular studies revealed that Junghuhnia is polyphyletic and most of the species cluster with Steccherinum, a morphologically similar genus separated only by a hydnoid hymenophore. In the Neotropics, very little is known about the evolutionary relationships of Junghuhnia s.lat. taxa and very few species have been included in molecular studies. In order to test the proper phylogenetic placement of Neotropical species of this group, morphological and molecular analyses were carried out. Specimens were collected in Brazil and used for DNA sequence analyses of the internal transcribed spacer and the large subunit of the nuclear ribosomal RNA gene, the translation elongation factor 1-α gene, and the second largest subunit of RNA polymerase II gene. Herbarium collections, including type specimens, were studied for morphological comparison and to confirm the identity of collections. The molecular data obtained revealed that the studied species are placed in three different genera. Specimens of Junghuhnia carneola represent two distinct species that group in a lineage within the phlebioid clade, separated from Junghuhnia and Steccherinum, which belong to the residual polyporoid clade. Therefore, the new genus Geesterania is proposed including two species, G. carneola comb. nov. and G. davidii sp. nov. Neotropical specimens identified as Junghuhnia nitida represent a different lineage from the European species and are described as Steccherinum neonitidum sp. nov. In addition, the new combinations Steccherinum meridionale, Steccherinum polycystidiferum and Steccherinum undigerum, as well as the new name Flaviporus tenuis, are proposed.

In vitro growth response of Phytophthora cactorum, P. nicotianae and P. × pelgrandis to antibiotics and fungicides.

The reactions of isolates of Phytophthora cactorum, P. nicotianae and P. × pelgrandis to metalaxyl, mancozeb, dimethomorph, streptomycin and chloramphenicol were tested to obtain information about the variability of resistance in these pathogens. Distinct genetic groups showed significant differences in resistance to all tested substances except streptomycin. In response to streptomycin, the growth inhibition rates of distinct groups did not differ significantly. The most remarkable differences were detected in the reactions to chloramphenicol and metalaxyl. Discriminant analysis evaluating the effect of all substances confirmed the differences among the groups, which are in agreement with the differences revealed by earlier DNA analyses.

The variability of Hosta virus X isolates in the Czech Republic.

The coat protein (CP) gene DNA sequences of nine isolates of Hosta virus X (HVX) from different regions of the Czech Republic were determined and compared with sequences available in GenBank. The sequences were almost uniform, the pairwise nucleotide identities among the Czech HVX isolates were 99-100%. The respective range was 98-100% when sequences from the GenBank were included. Therefore, phylogenetic analyses including Maximum parsimony and Bayesian analyses of either, DNA and deduced amino acid sequences, showed close relationship among isolates. Only the group of two isolates, HVXCR1 and HVXCR8 showed significant sequence divergence in phylogenetic trees. The HVXCR1-HVXCR8 group differs from the others by the substitution of glutamine (Q) by arginine (R). Moreover, these isolates showed different symptoms on infected hosta leaves - deformation on the leaves without a mosaic or mottling. This amino acid change may, therefore, have a biological significance.

Taxonomy and phylogeny of European Gymnopus subsection Levipedes (Basidiomycota, Omphalotaceae).

The systematic integrity of European Gymnopus subsect. Levipedes is verified based on anatomic-morphological characters with support from DNA sequences of ITS and translation elongation factor 1-alpha genes. Seven species (G. alpinus, G. aquosus, G. dryophilus - including var. lanipes, G. erythropus, G. fagiphilus, G. hybridus, and G. ocior) belonging to this subsection are included. We clarify the concepts of G. dryophilus and G. ocior, which were occasionally confused in older literature. Due to unavailability of previously selected neotype of G. dryophilus the substitute neotype specimen is selected. Gymnopus dryophilus var. lanipes is confirmed as a variety; no important differences from nominotypical variability were detected. All discriminative characters used for identification of these species are discussed in detail. An identification key is also provided.

European species of Clavaria (Agaricales, Agaricomycetes) with dark basidiomata - a morphological and molecular study.

Clavaria species with dark basidiomata occurring in Europe were analysed using morphological and molecular methods. Morphological analyses revealed four groups containing seven Clavaria species with dark basidiomata. Phylogenetic analysis of the LSU nrDNA region confirmed the separate positions of all seven Clavaria species within the genus. All sequences were grouped in four well-supported clades, mostly corresponding to defined morphological species. The results of the molecular study are inconsistent with the infrageneric classification of Clavaria based on the presence or absence of clamps on the bases of basidia and two widely accepted subgenera. Clavaria and Holocoryne appear to be polyphyletic. A new approach in species delimitation is presented: 1) C. asperulispora and C. atrofusca are two distinct species recognized by the shape of their spores, and the name C. neo-nigrita is a possible synonym of C. asperulispora; 2) species with clustered fragile basidiomata, C. fumosa and Clavaria cf. fuscoferruginea, which are almost identical in shape and size of spores differing only in the darker basidiomata of the latter, are phylogenetically unrelated; 3) Clavaria atrobadia is a dubious species, the name being most likely a synonym of C. fuscoferruginea; 4) two species with close morphological and phylogenetic affinity, C. atroumbrina and C. pullei, are distinguished based on the more oblong and narrower spores of the former. Comparison of European and North American material suggests the transatlantic nature of the distribution of C. asperulispora, C. atroumbrina and C. fumosa.

First Report of Root Rot of Pedunculate Oak and Other Forest Tree Species Caused by Phytophthora plurivora in the Czech Republic.

From 2006 to 2008, several similar Phytophthora isolates were obtained from roots of mature Quercus robur and other tree species (Acer platanoides, Fraxinus excelsior, Q. rubra, and Tilia cordata) in forests and parks in several areas in the Czech Republic. The trees were characterized by chlorotic and reduced foliage, crown dieback, and reduced root hairs. Several isolates of Phytophthora were obtained from necrotic roots of these trees and identified as Phytophthora plurivora Jung & Burgess (1). Isolated colonies grown on V8A medium were radiate to slightly chrysanthemum shaped with limited aerial mycelium in the center. Optimum growth was at 25°C, minimum at 5°C and maximum at 32°C. Radial growth of colonies averaged 6.4 mm/day at 20°C. The isolates were homothallic and produced abundant smooth-walled, spherical oogonia (23.3 to 29.1 µm in diameter), oospores were nearly plerotic or plerotic (21.8 to 26.9 µm in diameter), and the oospore wall was 1.2 to 1.4 µm thick. Antheridia were usually paragynous and measured 8.4 to 12 × 6.5 to 8 µm, but amphigynous antheridia were occasionally observed. Noncaducous, semipapillate sporangia formed on simple or sympodial sporangiophores, were obpyriform, ovoid, ellipsoid or irregular in shape, and occasionally distorted with more than one apex. Sporangia dimensions were 33 to 65 × 24 to 33 µm; L/B ratio 1.2 to 1.6 (-2.1). Comparison of DNA sequences of internal transcribed spacer (ITS) regions of isolates (representative strain GenBank Accession No. FJ952382) confirmed the 100% identity of P. plurivora (1). The soil infestation test was conducted using a P. plurivora isolate acquired from roots of Q. robur and 20 3-year-old plants of Q. robur. Sterilized millet seeds colonized by pathogen with the method as described (2) were used as inoculation medium and added into sterilized peat substrate at the rate of 0.5% (vol/vol). The plants were cultivated in 5.8-liter pots in a greenhouse (20°C, 16-h/8-h photoperiod). After 4 months, the roots of all plants were washed, dried, and weighed. The root biomass of 20 infected plants was significantly reduced by approximately 25% on average compared with the control 20 plants (P < 0.05, t-test, Statistica 7.1). The pathogen was consistently reisolated from the roots of infected plants but not from control plants. Stem inoculation tests were conducted with 20 replicates in each group of 2-year-old plants of oak, maple, ash, and lime and isolates acquired from the hosts. On each seedling, a 5-mm-diameter bark plug was removed 5 cm above the collar. The inoculum (5-mm-diameter V8A agar plug with actively growing mycelium) was applied to the exposed substrate. The wounds were sealed with Parafilm. Stem necrosis developed in all cases after 1 to 2 weeks, whereas control plants remained healthy. The pathogen was successfully reisolated from necrotic stem tissues. To our knowledge, this is the first report of P. plurivora causing root rot on oak, maple, ash, and lime in the Czech Republic. On the basis of the host range and distribution of P. plurivora in the Czech Republic, it can be assumed that, as elsewhere in Europe (1), this pathogen is widespread and is a common cause of decline of many tree species. References: (1) T. Jung and T. I. Burgess. Persoonia 22:95, 2009. (2) C. Robin et al. Plant Pathol. 50:708, 2001.

Production and regulation of lignocellulose-degrading enzymes of Poria-like wood-inhabiting basidiomycetes.

The wood-decomposing fungal species Antrodia macra, A. pulvinascens, Ceriporiopsis aneirina, C. resinascens and Dichomitus albidofuscus were determined for production of laccase (LAC), Mn peroxidase (MnP), lignin peroxidase (LiP), endo-l,4-P-beta-glucanase, endo-l,4-beta-xylanase, cellobiohydrolase, 1,4-beta-glucosidase and 1,4-beta-xylosidase. The results confirmed the brown-rot mode of Antrodia spp. which did not produce the activity of LAC and MnP. The remaining species performed detectable activity of both enzymes while no strain produced LiP. Significant inhibition of LAC production by high nitrogen was found in all white-rot species while only MnP of D. albidofuscus was regulated in the same way. The endoglucanase and endoxylanase activities of white-rotting species were inhibited by glucose in the medium while those of Antrodia spp. were not influenced by glucose concentration. The regulation of enzyme activity and bio-mass production can vary even within a single fungal genus.

First Report of Phoma exigua var. populi Causing Canker of Twigs and Shoots of Poplar in the Czech Republic.

During 2007 and the spring of 2008, a disease of poplars (Populus spp.) resembling the Dothichiza canker was found in plantations of fast-growing trees in central Bohemia and in southern Moravia where it was more abundant. The yellowish brown-to-brown, round or elongated cankers occurred on damaged shoots and twigs. Tissues directly under the bark were discolored and turned black. As the cankers enlarged, infected shoots and twigs died after several months. Small, black, gregarious pycnidia were observed under the bark or in lenticels after several weeks. The disease occurred on Populus nigra, P. × euroamericana cvs. Regenerata, Robusta, Brabantica, Spreewald, CZ-425/58, Blanc du Poitou, and Flaschlanden, and other Populus spp. Isolates of a species of Phoma were acquired by culturing damaged tissues on agar plates containing 3% oatmeal agar (OA) and 2% malt agar. Initial identification of the isolates was done by cultural and morphological characteristics (1). Colonies were floccose, aerial mycelium was olivaceous gray to gray, reverse olivaceous gray sometimes with darker tones at the margins or in the colony center, and NaOH reaction was negative. The growth rate was 42 to 56 in diameter after 7 days at 20°C on OA (optimum temperature for growth was 22°C with a minimum of 1°C and a maximum of 28 to 29°C). Pycnidia in culture scattered, were globose or subglobose, obviously with one nonpapillate ostiolum, olivaceous black or black, 120 to 370 µm in diameter, and conidial exudate was whitish. Phialides were globose to ampulliform and 3 to 7 × 3 to 6 µm. Conidia were hyaline, ellipsoidal, often guttulate, 3.1 to 7.8 × 1.9 to 3.1 µm, and L/B ratio 1.4:3.1. Septate conidia occurred only on natural substrate up to 10.6 × 3.9 µm. Morphological and cultural characteristics resembled those of P. exiqua var. populi Gruyter & P. Scheer (1). The internal transcribed spacer (ITS) sequence (GenBank Accession No EU562206) for the representative isolate (CCF No 3759) confirmed 100% identity to P. exigua. Pathogenicity was confirmed with 1-year-old P. nigra plants during a 2-month greenhouse experiment at 15 to 20°C. Fifteen replicate plants were wounded (5-mm diameter), inoculated with 5-mm OA plugs from actively growing colonies (isolate CCF No 3759), and sealed by Parafilming. An additional 15 control plants following wounding were inoculated with a sterile agar plug. After 3 to 4 weeks, yellowish or brownish necrotic lesions ranging from 1 to 1.5 cm long developed on all inoculated plants. The pathogen was successfully reisolated from lesions and the control plants were asymptomatic. P. exigua var. populi is considered an opportunistic poplar and willow pathogen (2) that becomes more important in winter (1). The pathogen potentially invades host tissues damaged by frost, sun scald, or weakened by excessive transpiration during sunny winter days. To our knowledge, this is the first record of the pathogen on poplars in the Czech Republic, which may have an economic impact on short-rotation coppice plantations. References: (1) J. de Gruyter and P. Scheer. J. Phytopathol. 146:411, 1998. (2) H. A. van der Aa et al. Persoonia 17:435, 2000.

First Report of Leaf Spot, Shoot Blight, and Stem and Collar Canker of Rhododendron spp. Caused by Phytophthora citricola in the Czech Republic.

During the summer and autumn of 2006, a disease of rhododendron plants (Ericaceae) was found in nurseries and public gardens in several areas of the Czech Republic. Leaves of damaged plants showed dark brown-to-black lesions extending along the mid-rib and commonly spreading to petioles and shoots. The infected shoots turned black and died. The cankers on branches, stems, and collars were characterized by reddish, brownish, or blackish discoloration. The disease was identified on Rhododendron catawbiense, R. repens, and other Rhododendron spp. After plating pieces of symptomatic tissue on PARPNH medium (2), several isolates of a homothallic Phytophthora sp. were acquired. Ten representative isolates of the pathogen were cultivated on V8A plates and examined for cultural and morphological characteristics. Colonies had a stellate pattern of growth with sparse aerial mycelium at 20°C; optimum temperature for growth was 25 to 28°C, minimum was 4°C, and maximum was 33°C. Radial growth was 14 mm per day at 20°C on V8A. The isolates produced terminal, spherical, smooth-walled oogonia, which were 19 to 37 µm in diameter. Oospores were plerotic (17 to 32 µm) with walls 2 to 4 µm thick; antheridia were paragynous. Single, terminal, noncaducous, semipapillate sporangia were formed on simple (occasionally sympodial) sporangiophores in nonsterile soil filtrate. The sporangia (28 to 61 × 24 to 35 µm, L:B ratio 1.5) were mostly obpyriform, rarely obovoid, or ovoid-ellipsoid. Morphological and cultural characters resembled those described for Phytophthora citricola Sawada (1). The ITS sequences of the rDNA of the two representative isolates (GenBank Accession Nos. EF194772 and EF194773) showed 100% homology to P. citricola sequences obtained from GenBank, thus the identity was confirmed as P. citricola. Both specimens were deposited in CCF (Culture Collection of Fungi, Charles University, Prague, Czech Republic). To confirm the pathogenicity of isolates, Koch's postulates were tested using 40 3-year-old potted rhododendron (R. catawbiense and R. repens) plants and the two P. citricola strains deposited in CCF. Surfaces of attached healthy leaves were disinfected with 95% ethanol and gently abraded with a sterile scalpel near the mid-rib. Agar plugs from the margin of a 5-day-old colony grown on carrot agar were placed on leaf surfaces and also inserted under flaps of stem tissues made with a sterile scalpel. The leaves and stems were then sealed with Parafilm. Control plants were treated in the same manner with sterile agar plugs. All plants were watered with deionized water, covered with a plastic bag, and maintained in a greenhouse at 21°C for 6 weeks. All inoculated plants exhibited necrotic lesions on leaves and stems around the points of inoculation after 4 days, whereas the control plants remained healthy. The pathogen was consistently reisolated from symptomatic plants. P. citricola is well known as a pathogen of rhododendron (1), but to our knowledge, this is the first report of P. citricola on Rhododendron sp. in the Czech Republic. P. citricola has been found at five different locations and in the most frequently isolated Phytophthora spp. from rhododendron in the Czech Republic. References: (1) D. C. Erwin and O. K. Ribeiro. Phytophthora Diseases Worldwide. The American Phytopathological Society. St. Paul, MN, 1996. (2) T. Jung et al. Eur. J. For. Pathol. 26:253, 1996.

Laccase and other ligninolytic enzyme activities of selected strains of Trametes spp. from different localities and substrates.

Eighty-three strains belonging to three species of the genus Trametes FR. (T. versicolor, T. hirsuta and T. ochracea) collected in different localities and on different substrates were screened for laccase production. The production of other lignin-modifying enzymes--manganese peroxidase (MnP) and lignin peroxidase (LiP)--and the decolorization ability were also determined in 21 of them. Production variability was relatively high and no significant correlation was found between the origin of the strains (locality, substrate) and the enzyme production. Dikaryons of all 3 species (but not of all their strains) exhibited LiP activity, which was not detected in the respective monokaryons.